Is there something I can read to get up to speed on xpath? Any recommendations for online or printed resources? (Particularly from folks who use it regularly!)
What Happened to XPath?
41–50 of 97 posts
Re: What Happened to XPath?
#42XPath post 1.0 got ridiculous, like many things do. What started with a simple, elegant language morphed into one with a http client, filesystem methods, json support, functions, loops, extensions and the ability to read environment variables. I wrote a post about it a while back[1] (I regret some of the wording used there) and maintain a tool[2] that can exploit XPath injection issues. I'd recommend sticking with 1…
XPath/XSLT 2+ also have only a single implementation (by the spec author) so don't meet W3C's requirement of two interoperating implementations. Basically, XSLT ceased to be a "standard" whereas XSLT 1.0 had excellent portability across libxslt, Saxon, Xalan, and MS' xslt.exe.
Edit: there is/was a token implementation for XSLT 2.0 called Gestalt
Re: What Happened to XPath?
#43XPath post 1.0 got ridiculous, like many things do. What started with a simple, elegant language morphed into one with a http client, filesystem methods, json support, functions, loops, extensions and the ability to read environment variables. I wrote a post about it a while back[1] (I regret some of the wording used there) and maintain a tool[2] that can exploit XPath injection issues. I'd recommend sticking with 1…
XPath always was extensible, at least at the implementation level. E.g. in 'lxml' it's trivial to add XPath functions with Python. Homegrown, of course, but still possible. In addition to extension elements this is about the only way to hook XSLT into the rest of the system. How else one is supposed to read environment variables from XSLT? The only other way is to pass everything via command line as parameters. It's…
> How else one is supposed to read environment variables from XSLT?
Setting aside whether it’s even a good idea to allow XSLT to do that, XPath is only a subset of XSLT, so you’re just changing the subject. The “path” in XPath should be a hint at what it’s supposed to be: a query language to select nodes by path in XML documents. As opposed to an alternative of Awk, or Perl.
Re: What Happened to XPath?
#44XPath post 1.0 got ridiculous, like many things do. What started with a simple, elegant language morphed into one with a http client, filesystem methods, json support, functions, loops, extensions and the ability to read environment variables. I wrote a post about it a while back[1] (I regret some of the wording used there) and maintain a tool[2] that can exploit XPath injection issues. I'd recommend sticking with 1…
XPath/XSLT 2+ also have only a single implementation (by the spec author) so don't meet W3C's requirement of two interoperating implementations. Basically, XSLT ceased to be a "standard" whereas XSLT 1.0 had excellent portability across libxslt, Saxon, Xalan, and MS' xslt.exe. Edit: there is/was a token implementation for XSLT 2.0 called Gestalt
Saxon supports all xpath versions though? It also bundles some very dangerous functions, some of which xcat can take advantage of.
Re: What Happened to XPath?
#45XPath 3 and XQuery 3 are powerful and great technologies to query XML if you need that stuff. The problem is that most implementations cover XPath 1.0 because I guess it is too difficult (i.e. time consuming and involved) to produce a 2.x or 3.x implementation, let alone with full W3C XML Schema support. There is also BaseX which implements XQuery 3.x which is a nice native XML database. I really dig XML and its technologies. I wish XQuery 3.x was available everywhere.
Re: What Happened to XPath?
#46XPath post 1.0 got ridiculous, like many things do. What started with a simple, elegant language morphed into one with a http client, filesystem methods, json support, functions, loops, extensions and the ability to read environment variables. I wrote a post about it a while back[1] (I regret some of the wording used there) and maintain a tool[2] that can exploit XPath injection issues. I'd recommend sticking with 1…
With the rise of numerous hierarchical document formats (JSON, YAML, TOML, properties files), what XPath REALLY should have evolved into was a more format-flexible path language with format-specific extensions as needed.
Re: What Happened to XPath?
#47Earlier quoted context omitted.
Every program attempts to expand until it can read mail. Those programs which cannot so expand are replaced by ones which can.
I was going to suggest Vim as a counterexample, but sure enough https://github.com/soywod/iris.vim
That's a community based plugin, Vim is still focused on text editing and not much else.
Re: What Happened to XPath?
#48Xpath is so powerful for web scraping I just realized recently. I'd been using css selectors for my occasional scraping needs and never bothered to learn xpath until on day on a whim decided to learn at least the basics. Man I can now write scrapers in 2 minutes that used to take me quite some time thanks to the power of xpath. Thing like ancestors, contains, the ability to chain, etc is so so powerful. I used to wri…
I realized a couple months back that Google sheets supports using xpath to scrape web pages. So now I have a "spreadsheet" scraping a page to see when a model of laptop goes on sale. Seems to work; at least, whenever I go double check that page manually it matches the scraped result.
Re: What Happened to XPath?
#49XPath and XSLT was the first time (despite doing Haskell at university) that I started to really understand functional programming. The first time was working on a tech stack that was basically Microsoft SHAPE queries transformed into HTML. The second was multiple projects customising Google custom search engine results. It was weird realising that these very limited primitive were actually infinitely powerful if you…
Indeed, xslt was the first pure functional language to achieve some popularity (if not love) among wider circles of software developers. At least, so it was in 2000s.
Re: What Happened to XPath?
#50XPath and XML in general is a great example of "Death by Committee". They tried too hard to be too smart and try to solve everything, and overcomplicated it to death. This is why people largely abandoned it. This is what is happening to C++ and they are steering themselves by committee into a dead end.