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Aron Woost
Aron Woost

Reputation: 20668

Case insensitive XPath contains() possible?

I'm running over all textnodes of my DOM and check if the nodeValue contains a certain string.

/html/body//text()[contains(.,'test')]

This is case sensitive. However, I also want to catch Test, TEST or TesT. Is that possible with XPath (in JavaScript)?

Upvotes: 128

Views: 124570

Answers (6)

kjhughes
kjhughes

Reputation: 111541

Modern XPath 2.0 (and higher) Solutions

  1. Use lower-case():

    /html/body//text()[contains(lower-case(.),'test')]

  2. Use matches() regex matching with its case-insensitive flag:

    /html/body//text()[matches(.,'test', 'i')]

For older XPath-1.0-limited environments, see the translate() technique described in @Tomalak's answer.

Upvotes: 75

Marvin Smit
Marvin Smit

Reputation: 4108

The way i always did this was by using the "translate" function in XPath. I won't say its very pretty but it works correctly.

/html/body//text()[contains(translate(.,'abcdefghijklmnopqrstuvwxyz',
                                        'ABCDEFGHIJKLMNOPQRSTUVWXYZ'),'TEST')]

hope this helps,

Upvotes: 7

Kirill Polishchuk
Kirill Polishchuk

Reputation: 56162

Case-insensitive contains

/html/body//text()[contains(translate(., 'EST', 'est'), 'test')]

Upvotes: 72

Tomalak
Tomalak

Reputation: 338208

This is for XPath 1.0. If your environment supports XPath 2.0, see here.

Yes. Possible, but not beautiful.

/html/body//text()[
  contains(
    translate(., 'ABCDEFGHIJKLMNOPQRSTUVWXYZ', 'abcdefghijklmnopqrstuvwxyz'),
    'test'
  )
]

This would work for search strings where the alphabet is known beforehand. Add any accented characters you expect to see.

If you can, mark the text that interests you with some other means, like enclosing it in a <span> that has a certain class while building the HTML. Such things are much easier to locate with XPath than substrings in the element text.

If that's not an option, you can let JavaScript (or any other host language that you are using to execute XPath) help you with building an dynamic XPath expression:

function xpathPrepare(xpath, searchString) {
  return xpath.replace("$u", searchString.toUpperCase())
              .replace("$l", searchString.toLowerCase())
              .replace("$s", searchString.toLowerCase());
}

xp = xpathPrepare("//text()[contains(translate(., '$u', '$l'), '$s')]", "Test");
// -> "//text()[contains(translate(., 'TEST', 'test'), 'test')]"

(Hat tip to @KirillPolishchuk's answer - of course you only need to translate those characters you're actually searching for.)

This approach would work for any search string whatsoever, without requiring prior knowledge of the alphabet, which is a big plus.

Both of the methods above fail when search strings can contain single quotes, in which case things get more complicated.

Upvotes: 146

Michael Kay
Michael Kay

Reputation: 163322

If you're using XPath 2.0 then you can specify a collation as the third argument to contains(). However, collation URIs are not standardized so the details depend on the product that you are using.

Note that the solutions given earlier using translate() all assume that you are only using the 26-letter English alphabet.

UPDATE: XPath 3.1 defines a standard collation URI for case-blind matching.

Upvotes: 7

Andy
Andy

Reputation: 9048

Yes. You can use translate to convert the text you want to match to lower case as follows:

/html/body//text()[contains(translate(., 
                                      'ABCDEFGHIJKLMNOPQRSTUVWXYZ',
                                      'abcdefghijklmnopqrstuvwxyz'),
                   'test')]

Upvotes: 13

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