How do I select child elements of any depth using XPath?

Question

Suppose I have this (simplified):

<form id="myform">
    <!-- some input fields -->
    <input type="submit" value="proceed"/>
</form>

Then I can select the submit button by XPath //form[@id='myform']/input[@type='submit']. Great.

However, my templates might change and I want to be flexible in the depth in which the submit button is located. It might be put in a table, like this:

<form id="myform">
    <!-- some input fields -->
    <table><tr><td>
           <input type="submit" value="proceed"/>
    </td></tr></table>
</form>

I know I can select elements which are grandchildren, but I can't select grand-grand-grand-...-childeren of any depth. E.g.:

//form[@id='myform']/*/input[@type='submit'] only selects grand-children, no further depths.
//form[@id='myform']/*/*/input[@type='submit'] only selects grand-grand-children, no further or less depths.
//form[@id='myform']/**/input[@type='submit'] is not valid.

So, how do I select this submit button reliably without using element IDs?

score 222 · Accepted Answer · answered Apr 15 '13 at 13:35

222

You're almost there. Simply use:

//form[@id='myform']//input[@type='submit']

The // shortcut can also be used inside an expression.

answered Apr 15 '13 at 13:35

nwellnhof

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C# doesn't seem to understand this notation. `//form//input` returns null in C# while Chrome can find 35 inputs using the same xpath – Achilles Mar 22 '15 at 07:27
1

My last comment is discussed here: http://stackoverflow.com/questions/23232671/xpath-selects-in-htmlagilitypack-dont-work-as-expected – Achilles Mar 22 '15 at 07:30
Check out this site for more XPath commands - https://www.scientecheasy.com/2019/08/xpath-axes.html/ – Herker Apr 08 '21 at 12:15

score 23 · Answer 2 · answered Jan 20 '17 at 02:30

23

If you are using the XmlDocument and XmlNode.

Say:

XmlNode f = root.SelectSingleNode("//form[@id='myform']");

Use:

XmlNode s = f.SelectSingleNode(".//input[@type='submit']");

It depends on the tool that you use. But .// will select any child, any depth from a reference node.

answered Jan 20 '17 at 02:30

s k

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Works well within Powershell using SelectSingleNode command on a certain XML node extracted earlier. – Gizmo3399 Mar 05 '19 at 10:52

score 11 · Answer 3 · edited Jul 01 '16 at 12:00

11

//form/descendant::input[@type='submit']

edited Jul 01 '16 at 12:00

dur

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answered Jul 01 '16 at 03:12

luis long

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11

add some description to it. – piyushj Jul 01 '16 at 03:33

How do I select child elements of any depth using XPath?

3 Answers3

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