How to use XPath in CasperJS' evaluate function

Question

We can use document.querySelector in the casper.evaluate function. But I could not find any documentation illustrating the use of XPath selectors inside the evaluate function. Is it possible to do the same? If yes, then how?

Answer 1

Basically all browsers support XPath through document.evaluate() . PhantomJS does so too (XPath 1.0).

CasperJS provides some convenience functions to use it. In the page context (inside casper.evaluate() ) there are the two functions __utils__.getElementByXPath(expression [, scope]) and __utils__.getElementsByXPath(expression [, scope]) .

This example prints the href of the first <a> element it finds that has a href attribute:

casper.echo(casper.evaluate(function(){
    return __utils__.getElementByXPath("//a[@href]").href
}));

CasperJS also supports XPath expressions outside of the page context with a helper function:

var x = require("casper").selectXPath;

which enables most CasperJS functions to use XPath expressions instead of CSS selectors:

casper.echo(casper.getElementAttribute(x("//a[@href]"), "href"));

^{This is similar, but not the same as the example above, because of the differences between element properties and attributes.}