Tables, your secret layout friend! Now with added lists.
This specification is an experimental breakup of the HTML specification. You can see the full list on the index page and take part in the discussion in the repository.
table
elementcaption
element,
followed by zero or more colgroup
elements, followed
optionally by a thead
element, followed optionally by
a tfoot
element, followed by either zero or more
tbody
elements or one or more tr
elements, followed optionally by a tfoot
element (but
there can only be one tfoot
element child in
total), optionally intermixed with one or more script-supporting elements.border
sortable
— Enables a sorting interface for the tablearia-*
attributes
applicable to the allowed roles.interface HTMLTableElement : HTMLElement { attribute HTMLTableCaptionElement? caption; HTMLElement createCaption(); void deleteCaption(); attribute HTMLTableSectionElement? tHead; HTMLElement createTHead(); void deleteTHead(); attribute HTMLTableSectionElement? tFoot; HTMLElement createTFoot(); void deleteTFoot(); readonly attribute HTMLCollection tBodies; HTMLElement createTBody(); readonly attribute HTMLCollection rows; HTMLElement insertRow(optional long index = -1); void deleteRow(long index); attribute boolean sortable; void stopSorting(); // also has obsolete members attribute DOMString border; };
The table
element represents data with more than one dimension, in
the form of a table.
The table
element takes part in the table
model. Tables have rows, columns, and cells given by their descendants. The rows and
columns form a grid; a table's cells must completely cover that grid without overlap.
Precise rules for determining whether this conformance requirement is met are described in the description of the table model.
Authors are encouraged to provide information describing how to interpret complex tables. Guidance on how to provide such information is given below.
Tables should not be used as layout aids. Historically, some Web authors have misused tables in HTML as a way to control their page layout. This usage is non-conforming, because tools attempting to extract tabular data from such documents would obtain very confusing results. In particular, users of accessibility tools like screen readers are likely to find it very difficult to navigate pages with tables used for layout.
There are a variety of alternatives to using HTML tables for layout, primarily using CSS positioning and the CSS table model. [[!CSS]]
The border
attribute may be specified on a
table
element to explicitly indicate that the
table
element is not being used for layout
purposes. If specified, the attribute\'s value must either be the empty string or the value
"1
". The attribute is used by certain user agents as an indication that borders
should be drawn around cells of the table.
Tables can be complicated to understand and navigate. To help users with this, user agents should clearly delineate cells in a table from each other, unless the user agent has classified the table as a (non-conforming) layout table.
Authors and implementors are encouraged to consider using some of the table design techniques described below to make tables easier to navigate for users.
User agents, especially those that do table analysis on arbitrary content, are encouraged to find heuristics to determine which tables actually contain data and which are merely being used for layout. This specification does not define a precise heuristic, but the following are suggested as possible indicators:
Feature | Indication |
---|---|
The use of the role attribute with the value presentation
| Probably a layout table |
The use of the border attribute with the non-conforming value 0
| Probably a layout table |
The use of the non-conforming cellspacing and
cellpadding attributes with the value 0
| Probably a layout table |
The use of caption , thead , or th elements
| Probably a non-layout table |
The use of the headers and scope attributes
| Probably a non-layout table |
The use of the border attribute with a value other than 0
| Probably a non-layout table |
Explicit visible borders set using CSS | Probably a non-layout table |
The use of the summary attribute
| Not a good indicator (both layout and non-layout tables have historically been given this attribute) |
It is quite possible that the above suggestions are wrong. Implementors are urged to provide feedback elaborating on their experiences with trying to create a layout table detection heuristic.
If a table
element has a (non-conforming) summary
attribute, and the user agent has not classified the
table as a layout table, the user agent may report the contents of that attribute to the user.
The sortable
attribute is used in the table
sorting model.
caption
[ = value ]Returns the table's caption
element.
Can be set, to replace the caption
element.
createCaption
()Ensures the table has a caption
element, and returns it.
deleteCaption
()Ensures the table does not have a caption
element.
tHead
[ = value ]Returns the table's thead
element.
Can be set, to replace the thead
element. If the new value is not a
thead
element, throws a HierarchyRequestError
exception.
createTHead
()Ensures the table has a thead
element, and returns it.
deleteTHead
()Ensures the table does not have a thead
element.
tFoot
[ = value ]Returns the table's tfoot
element.
Can be set, to replace the tfoot
element. If the new value is not a
tfoot
element, throws a HierarchyRequestError
exception.
createTFoot
()Ensures the table has a tfoot
element, and returns it.
deleteTFoot
()Ensures the table does not have a tfoot
element.
tBodies
Returns an HTMLCollection
of the tbody
elements of the table.
createTBody
()Creates a tbody
element, inserts it into the table, and returns it.
rows
Returns an HTMLCollection
of the tr
elements of the table.
insertRow
( [ index ] )Creates a tr
element, along with a tbody
if required, inserts them
into the table at the position given by the argument, and returns the tr
.
The position is relative to the rows in the table. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the table.
If the given position is less than −1 or greater than the number of rows, throws an
IndexSizeError
exception.
deleteRow
(index)Removes the tr
element with the given position in the table.
The position is relative to the rows in the table. The index −1 is equivalent to deleting the last row of the table.
If the given position is less than −1 or greater than the index of the last row, or if
there are no rows, throws an IndexSizeError
exception.
The caption
IDL attribute must return, on
getting, the first caption
element child of the table
element, if any,
or null otherwise. On setting, the first caption
element child of the
table
element, if any, must be removed, and the new value, if not null, must be
inserted as the first node of the table
element.
The createCaption()
method must return
the first caption
element child of the table
element, if any; otherwise
a new caption
element must be created, inserted as the first node of the
table
element, and then returned.
The deleteCaption()
method must remove
the first caption
element child of the table
element, if any.
The tHead
IDL attribute must return, on
getting, the first thead
element child of the table
element, if any, or
null otherwise. On setting, if the new value is null or a thead
element, the first
thead
element child of the table
element, if any, must be removed, and
the new value, if not null, must be inserted immediately before the first element in the
table
element that is neither a caption
element nor a
colgroup
element, if any, or at the end of the table if there are no such elements.
If the new value is neither null nor a thead
element, then a
HierarchyRequestError
DOM exception must be thrown instead.
The createTHead()
method must return the
first thead
element child of the table
element, if any; otherwise a new
thead
element must be created and inserted immediately before the first element in
the table
element that is neither a caption
element nor a
colgroup
element, if any, or at the end of the table if there are no such elements,
and then that new element must be returned.
The deleteTHead()
method must remove the
first thead
element child of the table
element, if any.
The tFoot
IDL attribute must return, on
getting, the first tfoot
element child of the table
element, if any, or
null otherwise. On setting, if the new value is null or a tfoot
element, the first
tfoot
element child of the table
element, if any, must be removed, and
the new value, if not null, must be inserted immediately before the first element in the
table
element that is neither a caption
element, a colgroup
element, nor a thead
element, if any, or at the end of the table if there are no such
elements. If the new value is neither null nor a tfoot
element, then a
HierarchyRequestError
DOM exception must be thrown instead.
The createTFoot()
method must return the
first tfoot
element child of the table
element, if any; otherwise a new
tfoot
element must be created and inserted immediately before the first element in
the table
element that is neither a caption
element, a
colgroup
element, nor a thead
element, if any, or at the end of the
table if there are no such elements, and then that new element must be returned.
The deleteTFoot()
method must remove the
first tfoot
element child of the table
element, if any.
The tBodies
attribute must return an
HTMLCollection
rooted at the table
node, whose filter matches only
tbody
elements that are children of the table
element.
The createTBody()
method must create a
new tbody
element, insert it immediately after the last tbody
element
child in the table
element, if any, or at the end of the table
element
if the table
element has no tbody
element children, and then must return
the new tbody
element.
The rows
attribute must return an
HTMLCollection
rooted at the table
node, whose filter matches only
tr
elements that are either children of the table
element, or children
of thead
, tbody
, or tfoot
elements that are themselves
children of the table
element. The elements in the collection must be ordered such
that those elements whose parent is a thead
are included first, in tree order,
followed by those elements whose parent is either a table
or tbody
element, again in tree order, followed finally by those elements whose parent is a
tfoot
element, still in tree order.
The behaviour of the insertRow(index)
method depends on the state of the table. When it is called,
the method must act as required by the first item in the following list of conditions that
describes the state of the table and the index argument:
rows
collection:IndexSizeError
exception.rows
collection has zero elements in it, and the
table
has no tbody
elements in it:tbody
element, then create a tr
element,
then append the tr
element to the tbody
element, then append the
tbody
element to the table
element, and finally return the
tr
element.rows
collection has zero elements in it:tr
element, append it to the last tbody
element in the table, and return the tr
element.rows
collection:tr
element, and append it to the parent of the last
tr
element in the rows
collection. Then, the
newly created tr
element must be returned.tr
element, insert it immediately before the indexth tr
element in the rows
collection, in the same parent, and finally must return the newly created tr
element.When the deleteRow(index)
method is called, the user agent must run the following
steps:
If index is equal to −1, then index must be
set to the number of items in the rows
collection, minus
one.
Now, if index is less than zero, or greater than or equal to the
number of elements in the rows
collection, the method must
instead throw an IndexSizeError
exception, and these steps must be aborted.
Otherwise, the method must remove the indexth element in the rows
collection from its parent.
The stopSorting()
method is used in the table
sorting model.
The IDL attribute sortable
must
reflect the sortable
content attribute.
Here is an example of a table being used to mark up a Sudoku puzzle. Observe the lack of headers, which are not necessary in such a table.
<section> <style scoped> table { border-collapse: collapse; border: solid thick; } colgroup, tbody { border: solid medium; } td { border: solid thin; height: 1.4em; width: 1.4em; text-align: center; padding: 0; } </style> <h1>Today's Sudoku</h1> <table> <colgroup><col><col><col> <colgroup><col><col><col> <colgroup><col><col><col> <tbody> <tr> <td> 1 <td> <td> 3 <td> 6 <td> <td> 4 <td> 7 <td> <td> 9 <tr> <td> <td> 2 <td> <td> <td> 9 <td> <td> <td> 1 <td> <tr> <td> 7 <td> <td> <td> <td> <td> <td> <td> <td> 6 <tbody> <tr> <td> 2 <td> <td> 4 <td> <td> 3 <td> <td> 9 <td> <td> 8 <tr> <td> <td> <td> <td> <td> <td> <td> <td> <td> <tr> <td> 5 <td> <td> <td> 9 <td> <td> 7 <td> <td> <td> 1 <tbody> <tr> <td> 6 <td> <td> <td> <td> 5 <td> <td> <td> <td> 2 <tr> <td> <td> <td> <td> <td> 7 <td> <td> <td> <td> <tr> <td> 9 <td> <td> <td> 8 <td> <td> 2 <td> <td> <td> 5 </table> </section>
For tables that consist of more than just a grid of cells with headers in the first row and headers in the first column, and for any table in general where the reader might have difficulty understanding the content, authors should include explanatory information introducing the table. This information is useful for all users, but is especially useful for users who cannot see the table, e.g. users of screen readers.
Such explanatory information should introduce the purpose of the table, outline its basic cell structure, highlight any trends or patterns, and generally teach the user how to use the table.
For instance, the following table:
Negative | Characteristic | Positive |
---|---|---|
Sad | Mood | Happy |
Failing | Grade | Passing |
...might benefit from a description explaining the way the table is laid out, something like "Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column".
There are a variety of ways to include this information, such as:
<p>In the following table, characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> <table> <caption>Characteristics with positive and negative sides</caption> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table>
caption
<table> <caption> <strong>Characteristics with positive and negative sides.</strong> <p>Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> </caption> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table>
caption
, in a details
element<table> <caption> <strong>Characteristics with positive and negative sides.</strong> <details> <summary>Help</summary> <p>Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> </details> </caption> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table>
figure
<figure> <figcaption>Characteristics with positive and negative sides</figcaption> <p>Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> <table> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table> </figure>
figure
's figcaption
<figure> <figcaption> <strong>Characteristics with positive and negative sides</strong> <p>Characteristics are given in the second column, with the negative side in the left column and the positive side in the right column.</p> </figcaption> <table> <thead> <tr> <th id="n"> Negative <th> Characteristic <th> Positive <tbody> <tr> <td headers="n r1"> Sad <th id="r1"> Mood <td> Happy <tr> <td headers="n r2"> Failing <th id="r2"> Grade <td> Passing </table> </figure>
Authors may also use other techniques, or combinations of the above techniques, as appropriate.
The best option, of course, rather than writing a description explaining the way the table is laid out, is to adjust the table such that no explanation is needed.
In the case of the table used in the examples above, a simple rearrangement of the table so
that the headers are on the top and left sides removes the need for an explanation as well as
removing the need for the use of headers
attributes:
<table> <caption>Characteristics with positive and negative sides</caption> <thead> <tr> <th> Characteristic <th> Negative <th> Positive <tbody> <tr> <th> Mood <td> Sad <td> Happy <tr> <th> Grade <td> Failing <td> Passing </table>
Good table design is key to making tables more readable and usable.
In visual media, providing column and row borders and alternating row backgrounds can be very effective to make complicated tables more readable.
For tables with large volumes of numeric content, using monospaced fonts can help users see patterns, especially in situations where a user agent does not render the borders. (Unfortunately, for historical reasons, not rendering borders on tables is a common default.)
In speech media, table cells can be distinguished by reporting the corresponding headers before reading the cell's contents, and by allowing users to navigate the table in a grid fashion, rather than serialising the entire contents of the table in source order.
Authors are encouraged to use CSS to achieve these effects.
User agents are encouraged to render tables using these techniques whenever the page does not use CSS and the table is not classified as a layout table.
caption
elementtable
element.table
elements.caption
element's end tag can be omitted if
the caption
element is not immediately followed by a space character or
a comment.aria-*
attributes
applicable to the allowed roles.interface HTMLTableCaptionElement : HTMLElement { // also has obsolete members };
The caption
element represents the title of the table
that is its parent, if it has a parent and that is a table
element.
The caption
element takes part in the table model.
When a table
element is the only content in a figure
element other
than the figcaption
, the caption
element should be omitted in favor of
the figcaption
.
A caption can introduce context for a table, making it significantly easier to understand.
Consider, for instance, the following table:
1 | 2 | 3 | 4 | 5 | 6 | |
---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 | 7 |
2 | 3 | 4 | 5 | 6 | 7 | 8 |
3 | 4 | 5 | 6 | 7 | 8 | 9 |
4 | 5 | 6 | 7 | 8 | 9 | 10 |
5 | 6 | 7 | 8 | 9 | 10 | 11 |
6 | 7 | 8 | 9 | 10 | 11 | 12 |
In the abstract, this table is not clear. However, with a caption giving the table's number (for reference in the main prose) and explaining its use, it makes more sense:
<caption> <p>Table 1. <p>This table shows the total score obtained from rolling two six-sided dice. The first row represents the value of the first die, the first column the value of the second die. The total is given in the cell that corresponds to the values of the two dice. </caption>
This provides the user with more context:
1 | 2 | 3 | 4 | 5 | 6 | |
---|---|---|---|---|---|---|
1 | 2 | 3 | 4 | 5 | 6 | 7 |
2 | 3 | 4 | 5 | 6 | 7 | 8 |
3 | 4 | 5 | 6 | 7 | 8 | 9 |
4 | 5 | 6 | 7 | 8 | 9 | 10 |
5 | 6 | 7 | 8 | 9 | 10 | 11 |
6 | 7 | 8 | 9 | 10 | 11 | 12 |
colgroup
elementtable
element, after any
caption
elements and before any thead
,
tbody
, tfoot
, and tr
elements.span
attribute is present: Nothing.span
attribute is absent: Zero or more col
and template
elements.colgroup
element's start tag can be
omitted if the first thing inside the colgroup
element is a col
element,
and if the element is not immediately preceded by another colgroup
element whose
end tag has been omitted. (It can't be omitted if the element
is empty.)colgroup
element's end tag can be omitted if
the colgroup
element is not immediately followed by a space character or
a comment.span
— Number of columns spanned by the elementinterface HTMLTableColElement : HTMLElement { attribute unsigned long span; // also has obsolete members };
The colgroup
element represents a group of one or more columns in the table
that is its parent, if it has a
parent and that is a table
element.
If the colgroup
element contains no col
elements, then the element
may have a span
content attribute specified,
whose value must be a valid non-negative integer greater than zero.
The colgroup
element and its span
attribute take part in the table model.
The span
IDL attribute must
reflect the content attribute of the same name. The value must be limited to
only non-negative numbers greater than zero.
col
elementcolgroup
element that doesn't have
a span
attribute.span
— Number of columns spanned by the elementHTMLTableColElement
, same as for
colgroup
elements. This interface defines one member,
span
.
If a col
element has a parent and that is a colgroup
element that
itself has a parent that is a table
element, then the col
element
represents one or more columns in the column group represented by that colgroup
.
The element may have a span
content attribute
specified, whose value must be a valid non-negative integer greater than zero.
The col
element and its span
attribute take
part in the table model.
The span
IDL attribute must reflect
the content attribute of the same name. The value must be limited to only non-negative
numbers greater than zero.
tbody
elementtable
element, after any
caption
, colgroup
, and
thead
elements, but only if there are no
tr
elements that are children of the
table
element.tr
and script-supporting elementstbody
element's start tag can be omitted
if the first thing inside the tbody
element is a tr
element, and if the
element is not immediately preceded by a tbody
, thead
, or
tfoot
element whose end tag has been omitted. (It
can't be omitted if the element is empty.)tbody
element's end tag can be omitted if
the tbody
element is immediately followed by a tbody
or
tfoot
element, or if there is no more content in the parent element.aria-*
attributes
applicable to the allowed roles.interface HTMLTableSectionElement : HTMLElement { readonly attribute HTMLCollection rows; HTMLElement insertRow(optional long index = -1); void deleteRow(long index); // also has obsolete members };
The HTMLTableSectionElement
interface is also
used for thead
and tfoot
elements.
The tbody
element represents a block of rows that consist of a
body of data for the parent table
element, if the tbody
element has a
parent and it is a table
.
The tbody
element takes part in the table model.
rows
Returns an HTMLCollection
of the tr
elements of the table
section.
insertRow
( [ index ] )Creates a tr
element, inserts it into the table section at the position given by
the argument, and returns the tr
.
The position is relative to the rows in the table section. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the table section.
If the given position is less than −1 or greater than the number of rows, throws an
IndexSizeError
exception.
deleteRow
(index)Removes the tr
element with the given position in the table section.
The position is relative to the rows in the table section. The index −1 is equivalent to deleting the last row of the table section.
If the given position is less than −1 or greater than the index of the last row, or if
there are no rows, throws an IndexSizeError
exception.
The rows
attribute must return an
HTMLCollection
rooted at the element, whose filter matches only tr
elements that are children of the element.
The insertRow(index)
method must, when invoked on an element table section, act as follows:
If index is less than −1 or greater than the number of elements in
the rows
collection, the method must throw an
IndexSizeError
exception.
If index is −1 or equal to the number of items in the rows
collection, the method must create a tr
element,
append it to the element table section, and return the newly created
tr
element.
Otherwise, the method must create a tr
element, insert it as a child of the table section element, immediately before the indexth
tr
element in the rows
collection, and finally
must return the newly created tr
element.
The deleteRow(index)
method must remove the indexth element in the rows
collection from its parent. If index is
less than zero or greater than or equal to the number of elements in the rows
collection, the method must instead throw an
IndexSizeError
exception.
thead
elementtable
element, after any
caption
, and colgroup
elements and before any tbody
, tfoot
, and
tr
elements, but only if there are no other
thead
elements that are children of the
table
element.tr
and script-supporting elementsthead
element's end tag can be omitted if
the thead
element is immediately followed by a tbody
or
tfoot
element.aria-*
attributes
applicable to the allowed roles.HTMLTableSectionElement
, as defined for
tbody
elements.The thead
element represents the block of rows that consist of
the column labels (headers) for the parent table
element, if the thead
element has a parent and it is a table
.
The thead
element takes part in the table model.
This example shows a thead
element being used. Notice the use of both
th
and td
elements in the thead
element: the first row is
the headers, and the second row is an explanation of how to fill in the table.
<table> <caption> School auction sign-up sheet </caption> <thead> <tr> <th><label for=e1>Name</label> <th><label for=e2>Product</label> <th><label for=e3>Picture</label> <th><label for=e4>Price</label> <tr> <td>Your name here <td>What are you selling? <td>Link to a picture <td>Your reserve price <tbody> <tr> <td>Ms Danus <td>Doughnuts <td><img src="http://example.com/mydoughnuts.png" title="Doughnuts from Ms Danus"> <td>$45 <tr> <td><input id=e1 type=text name=who required form=f> <td><input id=e2 type=text name=what required form=f> <td><input id=e3 type=url name=pic form=f> <td><input id=e4 type=number step=0.01 min=0 value=0 required form=f> </table> <form id=f action="/auction.cgi"> <input type=button name=add value="Submit"> </form>
tfoot
elementtable
element, after any
caption
, colgroup
, and thead
elements and before any tbody
and tr
elements, but only if there are no other tfoot
elements that are children of the table
element.table
element, after any
caption
, colgroup
, thead
,
tbody
, and tr
elements, but only if there
are no other tfoot
elements that are children of the
table
element.tr
and script-supporting elementstfoot
element's end tag can be omitted if
the tfoot
element is immediately followed by a tbody
element, or if
there is no more content in the parent element.aria-*
attributes
applicable to the allowed roles.HTMLTableSectionElement
, as defined for
tbody
elements.The tfoot
element represents the block of rows that consist of
the column summaries (footers) for the parent table
element, if the
tfoot
element has a parent and it is a table
.
The tfoot
element takes part in the table
model.
tr
elementthead
element.tbody
element.tfoot
element.table
element, after any
caption
, colgroup
, and thead
elements, but only if there are no tbody
elements that
are children of the table
element.td
, th
, and script-supporting elementstr
element's end tag can be omitted if the
tr
element is immediately followed by another tr
element, or if there is
no more content in the parent element.aria-*
attributes
applicable to the allowed roles.interface HTMLTableRowElement : HTMLElement { readonly attribute long rowIndex; readonly attribute long sectionRowIndex; readonly attribute HTMLCollection cells; HTMLElement insertCell(optional long index = -1); void deleteCell(long index); // also has obsolete members };
The tr
element represents a row of
cells in a table.
The tr
element takes part in the table model.
rowIndex
Returns the position of the row in the table's rows
list.
Returns −1 if the element isn't in a table.
sectionRowIndex
Returns the position of the row in the table section's rows
list.
Returns −1 if the element isn't in a table section.
cells
Returns an HTMLCollection
of the td
and th
elements of
the row.
insertCell
( [ index ] )Creates a td
element, inserts it into the table row at the position given by the
argument, and returns the td
.
The position is relative to the cells in the row. The index −1, which is the default if the argument is omitted, is equivalent to inserting at the end of the row.
If the given position is less than −1 or greater than the number of cells, throws an
IndexSizeError
exception.
deleteCell
(index)Removes the td
or th
element with the given position in the
row.
The position is relative to the cells in the row. The index −1 is equivalent to deleting the last cell of the row.
If the given position is less than −1 or greater than the index of the last cell, or
if there are no cells, throws an IndexSizeError
exception.
The rowIndex
attribute must, if the element has
a parent table
element, or a parent tbody
, thead
, or
tfoot
element and a grandparent table
element, return the index
of the tr
element in that table
element's rows
collection. If there is no such table
element,
then the attribute must return −1.
The sectionRowIndex
attribute must, if
the element has a parent table
, tbody
, thead
, or
tfoot
element, return the index of the tr
element in the parent
element's rows
collection (for tables, that's the HTMLTableElement.rows
collection; for table sections, that's the
HTMLTableRowElement.rows
collection). If there is no such
parent element, then the attribute must return −1.
The cells
attribute must return an
HTMLCollection
rooted at the tr
element, whose filter matches only
td
and th
elements that are children of the tr
element.
The insertCell(index)
method must act as follows:
If index is less than −1 or greater than the number of elements in
the cells
collection, the method must throw an
IndexSizeError
exception.
If index is equal to −1 or equal to the number of items in cells
collection, the method must create a td
element,
append it to the tr
element, and return the newly created td
element.
Otherwise, the method must create a td
element, insert it as a child of the
tr
element, immediately before the indexth td
or
th
element in the cells
collection, and finally
must return the newly created td
element.
The deleteCell(index)
method must remove the indexth element in the cells
collection from its parent. If index is less
than zero or greater than or equal to the number of elements in the cells
collection, the method must instead throw an
IndexSizeError
exception.
td
elementtr
element.td
element's end tag can be omitted if the
td
element is immediately followed by a td
or th
element,
or if there is no more content in the parent element.colspan
— Number of columns that the cell is to spanrowspan
— Number of rows that the cell is to spanheaders
— The header cells for this cellaria-*
attributes
applicable to the allowed roles.interface HTMLTableDataCellElement : HTMLTableCellElement { // also has obsolete members };
The td
element represents a data cell in a table.
The td
element and its colspan
, rowspan
, and headers
attributes take part in the table model.
User agents, especially in non-visual environments or where displaying the table as a 2D grid
is impractical, may give the user context for the cell when rendering the contents of a cell; for
instance, giving its position in the table model, or listing the cell's header cells
(as determined by the algorithm for assigning header cells). When a cell's header
cells are being listed, user agents may use the value of abbr
attributes on those header cells, if any, instead of the contents of the header cells
themselves.
In this example, we see a snippet of a Web application consisting of a grid of editable cells
(essentially a simple spreadsheet). One of the cells has been configured to show the sum of the
cells above it. Three have been marked as headings, which use th
elements instead of
td
elements. A script would attach event handlers to these elements to maintain the
total.
<table> <tr> <th><input value="Name"> <th><input value="Paid ($)"> <tr> <td><input value="Jeff"> <td><input value="14"> <tr> <td><input value="Britta"> <td><input value="9"> <tr> <td><input value="Abed"> <td><input value="25"> <tr> <td><input value="Shirley"> <td><input value="2"> <tr> <td><input value="Annie"> <td><input value="5"> <tr> <td><input value="Troy"> <td><input value="5"> <tr> <td><input value="Pierce"> <td><input value="1000"> <tr> <th><input value="Total"> <td><output value="1060"> </table>
th
elementth
element is a sorting interface th
element: Interactive content.tr
element.header
, footer
, sectioning content, or heading content descendants, and if the th
element is a sorting interface th
element, no interactive content descendants.th
element's end tag can be omitted if the
th
element is immediately followed by a td
or th
element,
or if there is no more content in the parent element.colspan
— Number of columns that the cell is to spanrowspan
— Number of rows that the cell is to spanheaders
— The header cells for this cellscope
— Specifies which cells the header cell applies toabbr
— Alternative label to use for the header cell when referencing the cell in other contextssorted
— Column sort direction and ordinalityaria-*
attributes
applicable to the allowed roles.interface HTMLTableHeaderCellElement : HTMLTableCellElement { attribute DOMString scope; attribute DOMString abbr; attribute DOMString sorted; void sort(); };
The th
element represents a header cell in a table.
The th
element may have a scope
content attribute specified. The scope
attribute is an
enumerated attribute with five states, four of which have explicit keywords:
row
keyword, which maps to the
row statecol
keyword, which maps to the
column staterowgroup
keyword, which maps to
the row group stateth
element's scope
attribute must
not be in the row group state if the element is not
anchored in a row group.colgroup
keyword, which maps to
the column group stateth
element's scope
attribute must
not be in the column group state if the element is
not anchored in a column group.The scope
attribute's missing value default is the
auto state.
The th
element may have an abbr
content attribute specified. Its value must be an alternative label for the header cell, to be
used when referencing the cell in other contexts (e.g. when describing the header cells that apply
to a data cell). It is typically an abbreviated form of the full header cell, but can also be an
expansion, or merely a different phrasing.
The sorted
attribute is used in the table
sorting model.
The th
element and its colspan
, rowspan
, headers
, and
scope
attributes take part in the table model.
The sort()
method is used in the table sorting
model.
The scope
IDL attribute must reflect
the content attribute of the same name, limited to only known values.
The abbr
and sorted
IDL attributes must reflect the
content attributes of the same name.
The following example shows how the scope
attribute's rowgroup
value affects which data cells a header cell
applies to.
Here is a markup fragment showing a table:
<table> <thead> <tr> <th> ID <th> Measurement <th> Average <th> Maximum <tbody> <tr> <td> <th scope=rowgroup> Cats <td> <td> <tr> <td> 93 <th scope=row> Legs <td> 3.5 <td> 4 <tr> <td> 10 <th scope=row> Tails <td> 1 <td> 1 <tbody> <tr> <td> <th scope=rowgroup> English speakers <td> <td> <tr> <td> 32 <th scope=row> Legs <td> 2.67 <td> 4 <tr> <td> 35 <th scope=row> Tails <td> 0.33 <td> 1 </table>
This would result in the following table:
ID | Measurement | Average | Maximum |
---|---|---|---|
Cats | |||
93 | Legs | 3.5 | 4 |
10 | Tails | 1 | 1 |
English speakers | |||
32 | Legs | 2.67 | 4 |
35 | Tails | 0.33 | 1 |
The headers in the first row all apply directly down to the rows in their column.
The headers with the explicit scope
attributes apply to all
the cells in their row group other than the cells in the first column.
The remaining headers apply just to the cells to the right of them.
td
and th
elementsThe td
and th
elements may have a colspan
content attribute specified, whose value must
be a valid non-negative integer greater than zero.
The td
and th
elements may also have a rowspan
content attribute specified, whose value must
be a valid non-negative integer. For this attribute, the value zero means that the
cell is to span all the remaining rows in the row group.
These attributes give the number of columns and rows respectively that the cell is to span. These attributes must not be used to overlap cells, as described in the description of the table model.
The td
and th
element may have a headers
content attribute specified. The headers
attribute, if specified, must contain a string consisting
of an unordered set of unique space-separated tokens that are
case-sensitive, each of which must have the value of an ID of a th
element taking part in the same table as the td
or th
element (as defined by the table model).
A th
element with ID id is
said to be directly targeted by all td
and th
elements in the
same table that have headers
attributes whose values include as one of their tokens
the ID id. A th
element A is said to be targeted by a th
or td
element
B if either A is directly targeted by B or if there exists an element C that is itself
targeted by the element B and A is directly
targeted by C.
A th
element must not be targeted by itself.
The colspan
, rowspan
, and headers
attributes take part in the table model.
The td
and th
elements implement interfaces that inherit from the
HTMLTableCellElement
interface:
interface HTMLTableCellElement : HTMLElement { attribute unsigned long colSpan; attribute unsigned long rowSpan; [PutForwards=value] readonly attribute DOMSettableTokenList headers; readonly attribute long cellIndex; // also has obsolete members };
cellIndex
Returns the position of the cell in the row's cells
list.
This does not necessarily correspond to the x-position of the cell in the
table, since earlier cells might cover multiple rows or columns.
Returns −1 if the element isn't in a row.
The colSpan
IDL attribute must
reflect the colspan
content attribute. Its
default value is 1.
The rowSpan
IDL attribute must
reflect the rowspan
content attribute. Its
default value is 1.
The headers
IDL attribute must
reflect the content attribute of the same name.
The cellIndex
IDL attribute must, if the
element has a parent tr
element, return the index of the cell's element in the parent
element's cells
collection. If there is no such parent element,
then the attribute must return −1.
The various table elements and their content attributes together define the table model.
A table consists of cells aligned on a two-dimensional grid of
slots with coordinates (x, y). The grid is finite, and is either empty or has one or more slots. If the grid
has one or more slots, then the x coordinates are always in the range 0 ≤ x < xwidth, and the y coordinates are always in the
range 0 ≤ y < yheight. If one or both of xwidth and yheight are zero, then the
table is empty (has no slots). Tables correspond to table
elements.
A cell is a set of slots anchored at a slot (cellx, celly), and with
a particular width and height such that the cell covers
all the slots with coordinates (x, y) where cellx ≤ x < cellx+width and celly ≤ y < celly+height. Cells can either be data cells
or header cells. Data cells correspond to td
elements, and header cells
correspond to th
elements. Cells of both types can have zero or more associated
header cells.
It is possible, in certain error cases, for two cells to occupy the same slot.
A row is a complete set of slots from x=0 to x=xwidth-1, for a particular value of y. Rows usually
correspond to tr
elements, though a row group
can have some implied rows at the end in some cases involving
cells spanning multiple rows.
A column is a complete set of slots from y=0 to y=yheight-1, for a particular value of x. Columns can
correspond to col
elements. In the absence of col
elements, columns are
implied.
A row group is a set of rows anchored at a slot (0, groupy) with a particular height such that the row group
covers all the slots with coordinates (x, y) where 0 ≤ x < xwidth and groupy ≤ y < groupy+height. Row groups correspond to
tbody
, thead
, and tfoot
elements. Not every row is
necessarily in a row group.
A column group is a set of columns anchored at a slot (groupx, 0) with a particular width such that the column group
covers all the slots with coordinates (x, y) where groupx ≤ x < groupx+width and 0 ≤ y < yheight. Column
groups correspond to colgroup
elements. Not every column is necessarily in a column
group.
Row groups cannot overlap each other. Similarly, column groups cannot overlap each other.
A cell cannot cover slots that are from two or more row groups. It is, however, possible for a cell to be in multiple column groups. All the slots that form part of one cell are part of zero or one row groups and zero or more column groups.
In addition to cells, columns, rows, row groups, and column
groups, tables can have a caption
element
associated with them. This gives the table a heading, or legend.
A table model error is an error with the data represented by table
elements and their descendants. Documents must not have table model errors.
To determine which elements correspond to which slots in a table associated with a table
element, to determine the
dimensions of the table (xwidth and yheight), and to determine if there are any table model errors, user agents must use the following algorithm:
Let xwidth be zero.
Let yheight be zero.
Let pending tfoot
elements be a list of tfoot
elements, initially empty.
Let the table be the table represented
by the table
element. The xwidth and yheight variables give the table's
dimensions. The table is initially empty.
If the table
element has no children elements, then return the
table (which will be empty), and abort these steps.
Associate the first caption
element child of the table
element with
the table. If there are no such children, then it has no associated
caption
element.
Let the current element be the first element child of the
table
element.
If a step in this algorithm ever requires the current element to be advanced to the next child of the table
when
there is no such next child, then the user agent must jump to the step labeled end, near
the end of this algorithm.
While the current element is not one of the following elements, advance the current element to the next
child of the table
:
If the current element is a colgroup
, follow these
substeps:
Column groups: Process the current element according to the appropriate case below:
col
element childrenFollow these steps:
Let xstart have the value of xwidth.
Let the current column be the first col
element child
of the colgroup
element.
Columns: If the current column col
element has
a span
attribute, then parse its value using the
rules for parsing non-negative integers.
If the result of parsing the value is not an error or zero, then let span be that value.
Otherwise, if the col
element has no span
attribute, or if trying to parse the attribute's value
resulted in an error or zero, then let span be 1.
Increase xwidth by span.
Let the last span columns in
the table correspond to the current column
col
element.
If current column is not the last col
element child of
the colgroup
element, then let the current column be the
next col
element child of the colgroup
element, and return to
the step labeled columns.
Let all the last columns in the
table from x=xstart to
x=xwidth-1 form a new column group, anchored at the slot (xstart, 0), with width xwidth-xstart, corresponding to the colgroup
element.
col
element childrenIf the colgroup
element has a span
attribute, then parse its value using the rules for parsing non-negative
integers.
If the result of parsing the value is not an error or zero, then let span be that value.
Otherwise, if the colgroup
element has no span
attribute, or if trying to parse the attribute's
value resulted in an error or zero, then let span be 1.
Increase xwidth by span.
Let the last span columns in
the table form a new column
group, anchored at the slot (xwidth-span, 0), with width span, corresponding to the colgroup
element.
While the current element is not one of the following elements, advance the current element to the
next child of the table
:
If the current element is a colgroup
element, jump to the
step labeled column groups above.
Let ycurrent be zero.
Let the list of downward-growing cells be an empty list.
Rows: While the current element is not one of the following
elements, advance the current
element to the next child of the table
:
If the current element is a tr
, then run the algorithm
for processing rows, advance the current element to the next child of the table
, and return to the
step labeled rows.
Run the algorithm for ending a row group.
If the current element is a tfoot
, then add that element to
the list of pending tfoot
elements, advance the current element to the next
child of the table
, and return to the step labeled rows.
The current element is either a thead
or a
tbody
.
Run the algorithm for processing row groups.
Return to the step labeled rows.
End: For each tfoot
element in the list of pending
tfoot
elements, in tree order, run the algorithm for processing row
groups.
If there exists a row or column in the table containing only slots that do not have a cell anchored to them, then this is a table model error.
Return the table.
The algorithm for processing row groups, which is invoked by the set of steps above
for processing thead
, tbody
, and tfoot
elements, is:
Let ystart have the value of yheight.
For each tr
element that is a child of the element being processed, in tree
order, run the algorithm for processing rows.
If yheight > ystart, then let all the last rows in the table from y=ystart to y=yheight-1 form a new row group, anchored at the slot with coordinate (0, ystart), with height yheight-ystart, corresponding to the element being processed.
Run the algorithm for ending a row group.
The algorithm for ending a row group, which is invoked by the set of steps above when starting and ending a block of rows, is:
While ycurrent is less than yheight, follow these steps:
Increase ycurrent by 1.
Empty the list of downward-growing cells.
The algorithm for processing rows, which is invoked by the set of steps above for
processing tr
elements, is:
If yheight is equal to ycurrent, then increase yheight by 1. (ycurrent is never greater than yheight.)
Let xcurrent be 0.
If the tr
element being processed has no td
or th
element children, then increase ycurrent by 1, abort
this set of steps, and return to the algorithm above.
Let current cell be the first td
or th
element child
in the tr
element being processed.
Cells: While xcurrent is less than xwidth and the slot with coordinate (xcurrent, ycurrent) already has a cell assigned to it, increase xcurrent by 1.
If xcurrent is equal to xwidth, increase xwidth by 1. (xcurrent is never greater than xwidth.)
If the current cell has a colspan
attribute, then parse that attribute's
value, and let colspan be the result.
If parsing that value failed, or returned zero, or if the attribute is absent, then let colspan be 1, instead.
If the current cell has a rowspan
attribute, then parse that attribute's
value, and let rowspan be the result.
If parsing that value failed or if the attribute is absent, then let rowspan be 1, instead.
If rowspan is zero and the table
element's
node document is not set to quirks mode, then let cell grows
downward be true, and set rowspan to 1. Otherwise, let cell grows downward be false.
If xwidth < xcurrent+colspan, then let xwidth be xcurrent+colspan.
If yheight < ycurrent+rowspan, then let yheight be ycurrent+rowspan.
Let the slots with coordinates (x, y) such that xcurrent ≤ x < xcurrent+colspan and ycurrent ≤ y < ycurrent+rowspan be covered by a new cell c, anchored at (xcurrent, ycurrent), which has width colspan and height rowspan, corresponding to the current cell element.
If the current cell element is a th
element, let this new
cell c be a header cell; otherwise, let it be a data cell.
To establish which header cells apply to the current cell element, use the algorithm for assigning header cells described in the next section.
If any of the slots involved already had a cell covering them, then this is a table model error. Those slots now have two cells overlapping.
If cell grows downward is true, then add the tuple {c, xcurrent, colspan} to the list of downward-growing cells.
Increase xcurrent by colspan.
If current cell is the last td
or th
element child in
the tr
element being processed, then increase ycurrent by 1, abort this set of steps, and return to the algorithm
above.
Let current cell be the next td
or th
element child
in the tr
element being processed.
Return to the step labeled cells.
When the algorithms above require the user agent to run the algorithm for growing downward-growing cells, the user agent must, for each {cell, cellx, width} tuple in the list of downward-growing cells, if any, extend the cell cell so that it also covers the slots with coordinates (x, ycurrent), where cellx ≤ x < cellx+width.
Each cell can be assigned zero or more header cells. The algorithm for assigning header cells to a cell principal cell is as follows.
Let header list be an empty list of cells.
Let (principalx, principaly) be the coordinate of the slot to which the principal cell is anchored.
headers
attribute specifiedTake the value of the principal cell's headers
attribute and split it on spaces, letting id list be the list of tokens
obtained.
For each token in the id list, if the
first element in the Document
with an ID equal to
the token is a cell in the same table, and that cell is not the
principal cell, then add that cell to header list.
headers
attribute specifiedLet principalwidth be the width of the principal cell.
Let principalheight be the height of the principal cell.
For each value of y from principaly to principaly+principalheight-1, run the internal algorithm for scanning and assigning header cells, with the principal cell, the header list, the initial coordinate (principalx,y), and the increments Δx=−1 and Δy=0.
For each value of x from principalx to principalx+principalwidth-1, run the internal algorithm for scanning and assigning header cells, with the principal cell, the header list, the initial coordinate (x,principaly), and the increments Δx=0 and Δy=−1.
If the principal cell is anchored in a row group, then add all header cells that are row group headers and are anchored in the same row group with an x-coordinate less than or equal to principalx+principalwidth-1 and a y-coordinate less than or equal to principaly+principalheight-1 to header list.
If the principal cell is anchored in a column group, then add all header cells that are column group headers and are anchored in the same column group with an x-coordinate less than or equal to principalx+principalwidth-1 and a y-coordinate less than or equal to principaly+principalheight-1 to header list.
Remove all the empty cells from the header list.
Remove any duplicates from the header list.
Remove principal cell from the header list if it is there.
Assign the headers in the header list to the principal cell.
The internal algorithm for scanning and assigning header cells, given a principal cell, a header list, an initial coordinate (initialx, initialy), and Δx and Δy increments, is as follows:
Let x equal initialx.
Let y equal initialy.
Let opaque headers be an empty list of cells.
Let in header block be true, and let headers from current header block be a list of cells containing just the principal cell.
Let in header block be false and let headers from current header block be an empty list of cells.
Loop: Increment x by Δx; increment y by Δy.
For each invocation of this algorithm, one of Δx and Δy will be −1, and the other will be 0.
If either x or y is less than 0, then abort this internal algorithm.
If there is no cell covering slot (x, y), or if there is more than one cell covering slot (x, y), return to the substep labeled loop.
Let current cell be the cell covering slot (x, y).
Set in header block to true.
Add current cell to headers from current header block.
Let blocked be false.
If there are any cells in the opaque headers list anchored with the same x-coordinate as the current cell, and with the same width as current cell, then let blocked be true.
If the current cell is not a column header, then let blocked be true.
If there are any cells in the opaque headers list anchored with the same y-coordinate as the current cell, and with the same height as current cell, then let blocked be true.
If the current cell is not a row header, then let blocked be true.
If blocked is false, then add the current cell to the headers list.
Set in header block to false. Add all the cells in headers from current header block to the opaque headers list, and empty the headers from current header block list.
Return to the step labeled loop.
A header cell anchored at the slot with coordinate (x, y) with width width and height height is said to be a column header if any of the following conditions are true:
scope
attribute is in the column state, orscope
attribute is in the auto state, and there are no data cells in any of the cells
covering slots with y-coordinates y .. y+height-1.A header cell anchored at the slot with coordinate (x, y) with width width and height height is said to be a row header if any of the following conditions are true:
scope
attribute is in the row state, orscope
attribute is in the auto state, the cell is not a column header, and
there are no data cells in any of the cells covering slots with x-coordinates
x .. x+width-1.A header cell is said to be a column group header if its scope
attribute is in the column
group state.
A header cell is said to be a row group header if its scope
attribute is in the row
group state.
A cell is said to be an empty cell if it contains no elements and its text content, if any, consists only of White_Space characters.
ul
elementli
element: Palpable content.li
and script-supporting elements.list
role (default - do not set), directory
, group
, listbox
, menu
, menubar
, presentation
,radiogroup
, tablist
, toolbar
or tree
.aria-*
attributes applicable to the allowed roles.interface HTMLUListElement : HTMLElement { // also has obsolete members };
The ul
element represents a list of items, where the order of the
items is not important — that is, where changing the order would not materially change the
meaning of the document.
The items of the list are the li
element child nodes of the ul
element.
The following markup shows a list where the order does not matter, and where the
ul
element is therefore appropriate. Compare this list to the equivalent list in the
ol
section to see an example of the same items using the ol
element.
<p>I have lived in the following countries:</p> <ul> <li>Norway <li>Switzerland <li>United Kingdom <li>United States </ul>
Note that changing the order of the list does not change the meaning of the document. The items in the snippet above are given in alphabetical order, but in the snippet below they are given in order of the size of their current account balance in 2007, without changing the meaning of the document whatsoever:
<p>I have lived in the following countries:</p> <ul> <li>Switzerland <li>Norway <li>United Kingdom <li>United States </ul>
ol
elementli
element: Palpable content.li
and script-supporting elements.reversed
— Number the list backwardsstart
— Ordinal value of the first itemtype
— Kind of list markerlist
role (default - do not set), directory
, group
, listbox
, menu
, menubar
, presentation
, radiogroup
, tablist
, toolbar
or tree
.aria-*
attributes applicable to the allowed roles.interface HTMLOListElement : HTMLElement { attribute boolean reversed; attribute long start; attribute DOMString type; // also has obsolete members };
The ol
element represents a list of items, where the items have been
intentionally ordered, such that changing the order would change the meaning of the document.
The items of the list are the li
element child nodes of the ol
element, in tree order.
The reversed
attribute is a boolean
attribute. If present, it indicates that the list is a descending list (..., 3, 2, 1). If
the attribute is omitted, the list is an ascending list (1, 2, 3, ...).
The start
attribute, if present, must be a
valid integer giving the ordinal value of the first list item.
If the start
attribute is present, user agents must parse it as an integer, in order to determine the
attribute's value. The default value, used if the attribute is missing or if the value cannot be
converted to a number according to the referenced algorithm, is 1 if the element has no reversed
attribute, and is the number of child li
elements otherwise.
The first item in the list has the ordinal value given by the ol
element's start
attribute, unless that li
element
has a value
attribute with a value that can be successfully
parsed, in which case it has the ordinal value given by that value
attribute.
Each subsequent item in the list has the ordinal value given by its value
attribute, if it has one, or, if it doesn't, the ordinal
value of the previous item, plus one if the reversed
is absent, or minus one if it is present.
The type
attribute can be used to specify the kind
of marker to use in the list, in the cases where that matters (e.g. because items are to be
referenced by their number/letter). The attribute, if specified, must have a value that is a
case-sensitive match for one of the characters given in the first cell of one of the
rows of the following table. The type
attribute represents the state given in the cell in the second column of the row whose first cell
matches the attribute's value; if none of the cells match, or if the attribute is omitted, then
the attribute represents the decimal
state.
Keyword | State | Description | Examples for values 1-3 and 3999-4001 | |||||||
---|---|---|---|---|---|---|---|---|---|---|
1 (U+0031)
| decimal | Decimal numbers | 1. | 2. | 3. | ... | 3999. | 4000. | 4001. | ... |
a (U+0061)
| lower-alpha | Lowercase latin alphabet | a. | b. | c. | ... | ewu. | ewv. | eww. | ... |
A (U+0041)
| upper-alpha | Uppercase latin alphabet | A. | B. | C. | ... | EWU. | EWV. | EWW. | ... |
i (U+0069)
| lower-roman | Lowercase roman numerals | i. | ii. | iii. | ... | mmmcmxcix. | i̅v̅. | i̅v̅i. | ... |
I (U+0049)
| upper-roman | Uppercase roman numerals | I. | II. | III. | ... | MMMCMXCIX. | I̅V̅. | I̅V̅I. | ... |
User agents should render the items of the list in a manner consistent with the state of the
type
attribute of the ol
element. Numbers less than
or equal to zero should always use the decimal system regardless of the type
attribute.
For CSS user agents, a mapping for this attribute to the 'list-style-type' CSS property is given in the rendering section (the mapping is straightforward: the states above have the same names as their corresponding CSS values).
It is possible to redefine the default CSS list styles used to implement this attribute in CSS user agents; doing so will affect how list items are rendered.
The reversed
, start
, and type
IDL attributes must reflect the
respective content attributes of the same name. The start
IDL
attribute has the same default as its content attribute.
The following markup shows a list where the order matters, and where the ol
element is therefore appropriate. Compare this list to the equivalent list in the ul
section to see an example of the same items using the ul
element.
<p>I have lived in the following countries (given in the order of when I first lived there):</p> <ol> <li>Switzerland <li>United Kingdom <li>United States <li>Norway </ol>
Note how changing the order of the list changes the meaning of the document. In the following example, changing the relative order of the first two items has changed the birthplace of the author:
<p>I have lived in the following countries (given in the order of when I first lived there):</p> <ol> <li>United Kingdom <li>Switzerland <li>United States <li>Norway </ol>
li
elementol
elements.ul
elements.menu
elements whose type
attribute is in the toolbar state.li
element's end tag can be omitted if the
li
element is immediately followed by another li
element or if there is
no more content in the parent element.ol
element: value
— Ordinal value of the list itemlistitem
role (default - do not set), menuitem
, menuitemcheckbox
, menuitemradio
, option
, radio
, tab
, treeitem
or presentation
.aria-*
attributes applicable to the allowed roles.interface HTMLLIElement : HTMLElement { attribute long value; // also has obsolete members };
The li
element represents a list item. If its parent element is an
ol
, ul
, or menu
element, then the element is an item of the
parent element's list, as defined for those elements. Otherwise, the list item has no defined
list-related relationship to any other li
element.
If the parent element is an ol
element, then the li
element has an
ordinal value.
The value
attribute, if present, must be a
valid integer giving the ordinal value of the list item.
If the value
attribute is present, user agents must parse it as an integer, in order to determine the
attribute's value. If the attribute's value cannot be converted to a number, the attribute must be
treated as if it was absent. The attribute has no default value.
The value
attribute is processed relative to the element's
parent ol
element (q.v.), if there is one. If there is not, the attribute has no
effect.
The value
IDL attribute must reflect
the value of the value
content attribute.
The following example, the top ten movies are listed (in reverse order). Note the way the list
is given a title by using a figure
element and its figcaption
element.
<figure> <figcaption>The top 10 movies of all time</figcaption> <ol> <li value="10"><cite>Josie and the Pussycats</cite>, 2001</li> <li value="9"><cite lang="sh">Црна мачка, бели мачор</cite>, 1998</li> <li value="8"><cite>A Bug's Life</cite>, 1998</li> <li value="7"><cite>Toy Story</cite>, 1995</li> <li value="6"><cite>Monsters, Inc</cite>, 2001</li> <li value="5"><cite>Cars</cite>, 2006</li> <li value="4"><cite>Toy Story 2</cite>, 1999</li> <li value="3"><cite>Finding Nemo</cite>, 2003</li> <li value="2"><cite>The Incredibles</cite>, 2004</li> <li value="1"><cite>Ratatouille</cite>, 2007</li> </ol> </figure>
The markup could also be written as follows, using the reversed
attribute on the ol
element:
<figure> <figcaption>The top 10 movies of all time</figcaption> <ol reversed> <li><cite>Josie and the Pussycats</cite>, 2001</li> <li><cite lang="sh">Црна мачка, бели мачор</cite>, 1998</li> <li><cite>A Bug's Life</cite>, 1998</li> <li><cite>Toy Story</cite>, 1995</li> <li><cite>Monsters, Inc</cite>, 2001</li> <li><cite>Cars</cite>, 2006</li> <li><cite>Toy Story 2</cite>, 1999</li> <li><cite>Finding Nemo</cite>, 2003</li> <li><cite>The Incredibles</cite>, 2004</li> <li><cite>Ratatouille</cite>, 2007</li> </ol> </figure>
While it is conforming to include heading elements (e.g. h1
) inside
li
elements, it likely does not convey the semantics that the author intended. A
heading starts a new section, so a heading in a list implicitly splits the list into spanning
multiple sections.
dl
elementdt
elements followed by one or more dd
elements, optionally intermixed with script-supporting elements.aria-*
attributes applicable to the allowed roles.interface HTMLDListElement : HTMLElement { // also has obsolete members };
The dl
element represents an association list consisting of zero or
more name-value groups (a description list). A name-value group consists of one or more names
(dt
elements) followed by one or more values (dd
elements), ignoring any
nodes other than dt
and dd
elements. Within a single dl
element, there should not be more than one dt
element for each name.
Name-value groups may be terms and definitions, metadata topics and values, questions and answers, or any other groups of name-value data.
The values within a group are alternatives; multiple paragraphs forming part of the same value
must all be given within the same dd
element.
The order of the list of groups, and of the names and values within each group, may be significant.
If a dl
element has no dt
or dd
element children, it
contains no groups.
If a dl
element has one or more non-whitespace Text
node children, or has child elements that are
neither dt
nor dd
elements, all such Text
nodes and
elements, as well as their descendants (including any dt
or dd
elements), do not form part of any groups in that dl
.
If a dl
element has one or more dt
element children but no
dd
element children, then it consists of one group with names but no values.
If a dl
element has one or more dd
element children but no
dt
element children, then it consists of one group with values but no names.
If a dl
element's first dt
or dd
element child is a
dd
element, then the first group has no associated name.
If a dl
element's last dt
or dd
element child is a
dt
element, then the last group has no associated value.
When a dl
element doesn't match its content model, it is often due to
accidentally using dd
elements in the place of dt
elements and vice
versa. Conformance checkers can spot such mistakes and might be able to advise authors how to
correctly use the markup.
In the following example, one entry ("Authors") is linked to two values ("John" and "Luke").
<dl> <dt> Authors <dd> John <dd> Luke <dt> Editor <dd> Frank </dl>
In the following example, one definition is linked to two terms.
<dl> <dt lang="en-US"> <dfn>color</dfn> </dt> <dt lang="en-GB"> <dfn>colour</dfn> </dt> <dd> A sensation which (in humans) derives from the ability of the fine structure of the eye to distinguish three differently filtered analyses of a view. </dd> </dl>
The following example illustrates the use of the dl
element to mark up metadata
of sorts. At the end of the example, one group has two metadata labels ("Authors" and "Editors")
and two values ("Robert Rothman" and "Daniel Jackson").
<dl> <dt> Last modified time </dt> <dd> 2004-12-23T23:33Z </dd> <dt> Recommended update interval </dt> <dd> 60s </dd> <dt> Authors </dt> <dt> Editors </dt> <dd> Robert Rothman </dd> <dd> Daniel Jackson </dd> </dl>
The following example shows the dl
element used to give a set of instructions.
The order of the instructions here is important (in the other examples, the order of the blocks
was not important).
<p>Determine the victory points as follows (use the first matching case):</p> <dl> <dt> If you have exactly five gold coins </dt> <dd> You get five victory points </dd> <dt> If you have one or more gold coins, and you have one or more silver coins </dt> <dd> You get two victory points </dd> <dt> If you have one or more silver coins </dt> <dd> You get one victory point </dd> <dt> Otherwise </dt> <dd> You get no victory points </dd> </dl>
The following snippet shows a dl
element being used as a glossary. Note the use
of dfn
to indicate the word being defined.
<dl> <dt><dfn>Apartment</dfn>, n.</dt> <dd>An execution context grouping one or more threads with one or more COM objects.</dd> <dt><dfn>Flat</dfn>, n.</dt> <dd>A deflated tire.</dd> <dt><dfn>Home</dfn>, n.</dt> <dd>The user's login directory.</dd> </dl>
The dl
element is inappropriate for marking up dialogue. Examples of how to mark up dialogue are shown below.
dt
elementdd
or dt
elements inside dl
elements.header
, footer
, sectioning content, or heading content descendants.dt
element's end tag can be omitted if the
dt
element is immediately followed by another dt
element or a
dd
element.aria-*
attributes
applicable to the allowed roles.HTMLElement
.The dt
element represents the term, or name, part of a
term-description group in a description list (dl
element).
The dt
element itself, when used in a dl
element, does
not indicate that its contents are a term being defined, but this can be indicated using the
dfn
element.
This example shows a list of frequently asked questions (a FAQ) marked up using the
dt
element for questions and the dd
element for answers.
<article> <h1>FAQ</h1> <dl> <dt>What do we want?</dt> <dd>Our data.</dd> <dt>When do we want it?</dt> <dd>Now.</dd> <dt>Where is it?</dt> <dd>We are not sure.</dd> </dl> </article>
dd
elementdt
or dd
elements inside dl
elements.dd
element's end tag can be omitted if the
dd
element is immediately followed by another dd
element or a
dt
element, or if there is no more content in the parent element.aria-*
attributes
applicable to the allowed roles.HTMLElement
.The dd
element represents the description, definition, or value, part
of a term-description group in a description list (dl
element).
A dl
can be used to define a vocabulary list, like in a dictionary. In the
following example, each entry, given by a dt
with a dfn
, has several
dd
s, showing the various parts of the definition.
<dl> <dt><dfn>happiness</dfn></dt> <dd class="pronunciation">/'hæ p. nes/</dd> <dd class="part-of-speech"><i><abbr>n.</abbr></i></dd> <dd>The state of being happy.</dd> <dd>Good fortune; success. <q>Oh <b>happiness</b>! It worked!</q></dd> <dt><dfn>rejoice</dfn></dt> <dd class="pronunciation">/ri jois'/</dd> <dd><i class="part-of-speech"><abbr>v.intr.</abbr></i> To be delighted oneself.</dd> <dd><i class="part-of-speech"><abbr>v.tr.</abbr></i> To cause one to be delighted.</dd> </dl>