7.18. Opt_Xml_Scannable class
7.18.8. getElementsExt()
7.18.7. getElementsByTagNameNS()
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7.18.8. getElementsExt()

Statuspublic
Referencearray getElementsExt(string $namespace, string $name)
Versionssince 2.0-dev8

This method works much like Opt_Xml_Scannable::getElementsByTagNameNS(), however it does not check the descendants of matching nodes. Its use is very common in OPT. Suppose we are writing the new instruction processor. The main instruction tag is opt:foo, but it must have also a descendant opt:bar:

<opt:foo>
    <div>
        <opt:bar>Hello world!</opt:bar>
    </div>
</opt:foo>

While parsing opt:foo we need to find the opt:bar for some reason and moreover simply to check if it is defined exactly once:

$barNodes = $node->getElementsByTagNameNS('opt', 'bar');
if(sizeof($nodes) != 1)
{
    throw new Opt_InstructionTooManyItems_Exception('opt:bar', 'opt:foo', 'One');
}

The first impression is that this code is correct. However, let's take a look at the following situation:

<opt:foo>
    <div>
        <opt:bar>
 
            <opt:foo>
                <div>
                    <opt:bar>Hello world!</opt:bar>
                </div>
            </opt:foo>
 
        </opt:bar>
    </div>
</opt:foo>

In this case the code above will surely cause error, even if it is easily noticeable that the second opt:bar should be connected to the nested opt:foo! Here, we must use getElementsExt():

$barNodes = $node->getElementsExt('opt', 'bar');
if(sizeof($nodes) != 1)
{
    throw new Opt_InstructionTooManyItems_Exception('opt:bar', 'opt:foo', 'One');
}

As this method does not visit the descendants of opt:bar, everything starts to work.

See also:

7.18.8. getElementsExt()
7.18. Opt_Xml_Scannable class
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7.18.7. getElementsByTagNameNS()
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7.18.9. getLastChild()