Question

I have the following text

<pattern name="pattern1"/>
<success>success case 1</success>
<failed> failure 1</failed>
<failed> failure 2</failed>
<unknown> unknown </unknown>
<pattern name="pattern4"/>
<pattern name="pattern5"/>        
<success>success case 3</success> 
<pattern name="pattern2"/>        
<success>success case 2</success>
<otherTag>There are many other tags.</otherTag>
<failed> failure 3</failed>
<pattern name="pattern3"/> 
<unknown>unkown</unknown> 

And the regular expression <failed>[\w|\W]*?</failed> matches all the lines contains failed tag.

What do I need to to if I want all failed tags and the pattern tag above the failed tag. if there is no failed tag underneath a pattern tag, then the pattern tag should not be matched?
Basically, I want the following output:

<pattern name="pattern1"/>
<failed> failure 1</failed>
<failed> failure 2</failed>
<pattern name="pattern2"/>
<failed> failure 3</failed>

I am doing this in javascript, I do not mind of doing some intermediate steps.

edit start
Almost all repliers suggest me to take a different approach. I am unsure which approach I should take. JQuery, regex or others. I am giving more information here for better decision making.
The data format would change, but would not change often. The data is from a schematron validition report of file type “.SVRL” The structure of the file are have the following schema defined using “RELAX NG compact syntax“

schematron-output   = element schematron-output {
attribute title { text }?,
attribute phase { xsd:NMTOKEN }?,
attribute schemaVersion { text }?,
    human-text*,
    ns-prefix-in-attribute-values*,
    (active-pattern,
    (fired-rule, (failed-assert | successful-report)*)+)+
}

the maps to active-pattern, and matches to failed-assert and successful-report respectively.

Now with additional information, which approach should I be taking?
Thanks very much for helping out. 🙂

edit end

Answer 1

Here are the RegExp you need:

<(pattern|failed)\b[^>]*(?:/>|>[^<]*</\1>)

Just escape the slashes when using in Javascript regular expression notation:

var regExp = /<(pattern|failed)\b[^>]*(?:\/>|>[^<]*<\/\1>)/gi;
var matchesArray = testString.match(regExp);

This regular expression will find whole <pattern> and <failed> tags, either if they are empty tags or not (<empty/> or <notEmpty></notEmpty>). It also considers possible element attributes.