XPath queries in Google Chrome console

Question

I can use XPath queries in Google Chrome's console like that:

a = $x('my/path')

However, what if I want to find an XPath relatively to another object? E.g.:

b = a.$x('my/path')

(does not work), also:

b = $x('my/path', a)

fails with: NotSupportedError: Failed to execute 'evaluate' on 'Document': The context node provided is null.

Does anybody know how to evaluate relative XPaths in Google Chrome's developer console?

Answer 1

Evaluating $x returns ...

function $x(xpath, [startNode]) { [Command Line API] }

So, the syntax is $x('my/path', a).

Important is that, $x returns an array but startNoderequires a DOM node, so you have to take an element of the first query. The following sample demonstrates the behavior on the current page.

a = $x("//*[@id='question-header']")
> [ <div id=​"question-header">​…​</div>​ ]

b = $x(".//*[@href]/text()", a[0])
> [ "XPath queries in Google Chrome console" ]

Update: Here is the documentation.