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What Happened to XPath?

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Re: What Happened to XPath?

#71

Post by mattmanser »

masklinn wrote: post #24
irjustin wrote: post #4

Anyone who does scraping or automated browser work eventually comes across XPath. In some ways, XPath is like regex. It's got insane power, but comes with a relatively steep learning curve. Remember reading regex for the first time? What? But unlike regex, the number of people using it are few in comparison. I avoided XPath until I couldn't anymore. I could do a lot with CSS selectors, but eventually the DOM traversa…

> In some ways, XPath is like regex. It's got insane power, but comes with a relatively steep learning curve. Remember reading regex for the first time? What? But unlike regex, the number of people using it are few in comparison. IMO the learning curve of XPath is not that high though, it has a somewhat alien syntax but the only thing I remember giving me trouble is axis , because most tutorials just go on with the "…

Many moons ago I worked somewhere that used XPath extensively.

Definitely a serious learning curve, some of the developers really struggled with it, others went crazy on it.

I made a pivot table maker with it. It was crazy fast vs the js version I originally tried back in the pre-v8 engine days. The js version would basically die after you got past a trivial amount of data, the xlst one was instant regardless of the amount of data.

Re: What Happened to XPath?

#72

Post by riku_iki »

layoutIfNeeded wrote: post #10
orf wrote: post #2

XPath 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…

I've read your article... Holy shit. They took a simple, sed-like tool and turned it into an abomination.

Curious what is the problem with this? You can still use your small sed-like subset of language in your project?

Re: What Happened to XPath?

#73

Post by anonymous324 »

benibela wrote: post #30

The biggest problem with the new XPath versions is that the W3C made the standards, but almost no one implemented them, so you cannot actually use them I was doing web scraping, and needed regular expressions to get the text, so I have implemented XPath 2. And currently I am updating it to XPath 3.1: http://www.videlibri.de/xidel.html

Though I've never used Xidel, I came across it when researching XPath 2/3, and was very impressed that anyone managed to implement these massive, complicated specs all by themselves.

The major OSS XML libs, including LibXML2 and Xerces, do not implement what Xidel does, and neither to some proprietary libs like MSXML.

Re: What Happened to XPath?

#75

Post by forgotmypw17 »

nunez wrote: post #55
orf wrote: post #2

XPath 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…

Damn. XPath went off the rails after v2. Though, to be fair, so did JavaScript, and look where that is today!

A bloated abomination?

Re: What Happened to XPath?

#76

Post by taway611 »

riku_iki wrote: post #72
layoutIfNeeded wrote: post #10

Earlier quoted context omitted.

I've read your article... Holy shit. They took a simple, sed-like tool and turned it into an abomination.

Curious what is the problem with this? You can still use your small sed-like subset of language in your project?

>>> They took a simple, sed-like tool and turned it into an abomination.

> Curious what is the problem with this?

Product Managers.

Re: What Happened to XPath?

#77

Post by dehrmann »

One of the huge gaps in JSON tooling is there isn't a standard XPath equivalent (there's JSON Pointer, but it's nowhere close to XPath, and JSON Path which isn't standardized) and no XSLT equivalent.

For as painful as XSLT was, at least it was a standard thing that existed.

Re: What Happened to XPath?

#78

Post by pojzon »

forgotmypw17 wrote: post #75
nunez wrote: post #55

Earlier quoted context omitted.

Damn. XPath went off the rails after v2. Though, to be fair, so did JavaScript, and look where that is today!

A bloated abomination?

Abomination with 500000 open job offerts and ppl wanting their page to load 2 minutes, because we can do that “async” and download half of internet to display a table.

Re: What Happened to XPath?

#79

Post by acdha »

masklinn wrote: post #31
benibela wrote: post #30

The biggest problem with the new XPath versions is that the W3C made the standards, but almost no one implemented them, so you cannot actually use them I was doing web scraping, and needed regular expressions to get the text, so I have implemented XPath 2. And currently I am updating it to XPath 3.1: http://www.videlibri.de/xidel.html

> I was doing web scraping, and needed regular expressions to get the text, so I have implemented XPath 2. Most XPath implementations have no issue with adding extension functions (in fact many support exslt[0] out of the box), you really do not need to use (let alone implement) XPath 2.0 to use regex functions. [0] http://exslt.org/regexp/index.html

I don't think this especially changes the underlying point: anyone using tools which were based on libxml2 or xerces is basically stuck in 1999. Having to find and install custom extensions adds a regular frictional cost which encourages you to just do more work in a full programming language since you know you'll be able to satisfy any requirement that way.

I saw so many developers sour on XML after hitting the “This would be easy if we used XPath 2 but instead it's hard” wall that I wonder if anyone on the relevant standards committees ever thought about how much libxml2 would make their work relevant.

Re: What Happened to XPath?

#80

Post by contravariant »

ping_pong wrote: post #50

XPath 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.

What, you think tying namespaces to a web domain that is in no way actually used as one and results in XML that is unreadable in its fully qualified form (or in fact not even valid XML) and changes not just meaning but value as you try to copy paste any part of it, was a bad idea?
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