正则表达式到 select 前 n 个单词和 HTML 标签周围

Question

I know its possible to select only words or select only HTML tags in a given string. But is it possible to select both?

In this example lets say we want to select first 5 words and HTML tags around them:

Input:

<p><strong>This is</strong> <span style="font-size: 1em;">test</span> <strong><em>five</em></strong> words.</p> 
test <p>Lorem Ipsum is simply dummy text of the printing and typesetting industry.</p>

Expected Output:

<p><strong>This is</strong> <span style="font-size: 1em;">test</span> <strong><em>five</em></strong> words.</p>

It's straight forward to write regexp to match all words or to match all HTML tags but not sure how to achieve above result using only regexp.

Answer 1

I know it's not regexp, but it is pure javascript and mostly the preferred method when working with 'selecting nodes' in a document: XPath.

With this piece of XPath you will select the largest node containing the text "This is test":

document.evaluate("/html/body//*[contains(.,'This is test')]", document);

In your example, the first <p> will get selected, including its child tags.

The above function returns an XPathResult and you'll have to iterate over it to do whatever you wnat with it. You can iterate over it again to get all childnodes back or just the text of it. Iterating over the result set and extracting the data should be recursive, but I just created a simple example to get the idea.

An example jsFiddle