In Tritium, what are the differences between CSS and XPath selectors?

Question

What are the advantages / disadvantages of the two different selectors?

Should I use one over the other?

tdesikan · Accepted Answer · 2013-06-07T19:10:12.710

2

I think it's primarily a matter of user preference.

To select the first child of all <p> elements, you'd do:

I prefer using Xpath, but YMMV.

Note that, internally, all CSS selectors are converted to Xpath. For example, the selector $$("#one") will be converted into $(".//*[id='one']").

edited Jun 07 '13 at 19:10

answered May 31 '13 at 04:45

tdesikan

I read somewhere that CSS selectors are sometimes faster, but I think that's on client side DOM manipulation. Are there any metrics regarding performance of selectors in the Moovweb SDK? – gregorygtseng May 31 '13 at 18:43
1

As Aaron says in this response, the difference in CSS selector and Xpath selector performance is negligible. In both cases, you can scope your search to ensure faster performance. – tdesikan Jun 07 '13 at 19:12

score 2 · Answer 2 · answered May 31 '13 at 08:14

2

Just a few notes:

indexing starts from 1 in XPath, so it's //p/*[1]
the CSS selectors in Tritium allow you to prefix a selector with >, as in $$("> p > :first-child"); this will be converted into a scoped search (i.e., ./p/*[1])
because CSS selectors are (currently) dynamically converted into XPath, there's a slight performance hit compared to using straight XPath

answered May 31 '13 at 08:14

Aaron Leung

Why are CSS selectors converted to XPath? – gregorygtseng May 31 '13 at 18:43
1

Because the current implementation of Tritium uses LibXML, which only supports XPath selectors. – Aaron Leung Jun 06 '13 at 00:40

2 Answers2