Selectors API support in Opera Presto 2.7

W3C reference

Selectors API Level 1

Opera Presto provides support for the Selectors API Level 1.

NodeSelector interface

The NodeSelector interface is implemented by objects implmenting the following interfaces:

• Document
• DocumentFragment
• Element

Opera Presto's support is described in the following data table.

Method	Description	Support
querySelector()	This method must, when invoked, return the first matching Element node within the node's subtrees. If there is no such node, the method must return null. This method takes a selector string (selectors) as its argument.	Yes
querySelectorAll()	This method must, when invoked, return a NodeList containing all of the matching Element nodes within the node's subtrees, in document order. If there are no such nodes, the method must return an empty NodeList. This method takes a selector string (selectors) as its argument. The NodeList object returned by the querySelectorAll() method must be static, not live.	Yes

Example

This is an example table written in HTML 4.01.

<table id="score">
  <thead>
    <tr>
      <th>Test
      <th>Result
  <tfoot>
    <tr>
      <th>Average
      <td>82%
  <tbody>
    <tr>
      <td>A
      <td>87%
    <tr>
      <td>B
      <td>78%
    <tr>
      <td>C
      <td>81%
</table>

In order to obtain the cells containing the results in the table, the following selector query may be used.

var cells = document.querySelectorAll("#score>tbody>tr>td:nth-of-type(2)");

This example returns a node list containing each of the cells in the second column. This could be useful, for example, to plot the values on a graph.

Selector API baseline tests

The Selector API baseline test case is composed of 1008 individual tests. Opera Presto registers a 100% pass rate when the test case is run. For your reference, the test case can be run here: W3C Baseline Tests: HTML with CSS Level 2.1 Selectors.