Comment by samsk

5 months ago

Nice ! I've a scrapper using XPath/XSLT extensively and 90% of the XPath selectors work like for years without a change. With CSS selectors I've had more problems...

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samsk

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ebruchez  5 months ago

CSS selectors have spent the last few decades reinventing XPath. XPath introduced right from the beginning the notion of axes, which allow you to navigate down, up, preceding, following, etc. as makes sense. XPath also always had predicates, even in version 1.0. CSS just recently started supporting :has() and :is(), in particular. Eventually, CSS selectors will match XPath's query abilities, although with worse syntax.

  • samsk  5 months ago

    The problem with CSS selectors (at least in scrapers) is also that they change relatively often, compared to (html) document structure, thats why XPath last longer. But you are right, CSS selectors compared to 20 years old XPath are realy worse.

  • masklinn  5 months ago

    On the other hand:

    - XPath literally didn't exist when CSS selectors were introduced

    - XPath's flexibility makes it a lot more challenging to implement efficiently, even more so when there are thousands of rules which need to be dynamically reevaluated at each document update

    - XPath is lacking conveniences dedicated to HTML semantics, and handrolling them in xpath 1.0 was absolutely heinous (go try and implement a class predicate in xpath 1.0 without extensions)

  • bambax  5 months ago

    > CSS selectors have spent the last few decades reinventing XPath

    YES! This is so true! And ridiculous! It's a mystery why we didn't simply reuse XPath for selectors... it's all in there!!

    • masklinn  5 months ago

      > It's a mystery why we didn't simply reuse XPath for selectors... it's all in there!!

      It's not really a mystery:

      > CSS was first proposed by Håkon Wium Lie on 10 October 1994. [...] discussions on public mailing lists and inside World Wide Web Consortium resulted in the first W3C CSS Recommendation (CSS1) being released in 1996

      > XPath 1.0 was published in 1999

      CSS2 was released before XPath 1.0.

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