CODEWITHSUNDEEP
javascriptregex
richwol
richwol

Reputation: 1165

Regular expression make matches less greedy

I have the following string:

<h2><!--DEL-->This is the title<!-- /DEL --><!-- ADD--><% title %><!--/ADD--></h2>

<!--ADD-->
<strong>some emphasised text</strong>
<!--/ADD-->

<ul>
    <!--ADD--><% for each item in list %>   <!--/ADD--> <li><!--DEL-->This is the first item in the list<!--/DEL--><!--ADD--><% item %><!--/ADD--></li><!--ADD--><% end for %><!--  /ADD -->
    <!--DEL--><li>This is the second item in the list</li><!--/DEL -->
    <!--DEL--><li>This is the <strong>third</strong> item in the list</li><!-- /DEL    -->
</ul>

Via regular expressions I want it to produce the following:

<h2><% title %></h2>

<strong>some emphasised text</strong>

<ul>
    <% for each item in list %><li><% item %></li><% end for %>
</ul>

The regular expressions I'm using:

template = template.replace(/<\!--\s*?DEL\s*?-->(.*)<\!--\s*?\/DEL\s*?-->/gm, "");
template = template.replace(/<\!--\s*?ADD\s*?-->(.*)<\!--\s*?\/ADD\s*?-->/gm, "$1");

But at the moment it's producing:

<h2><% title %></h2>
<ul>
  <% for each item in list %><!-- /ADD --><li><!-- ADD --><% item %><!-- /ADD --></li><!-- ADD --><% end for %>
</ul>

Problem 1: It doesn't seem to like it when there's multiple matches on the same line (it seems to treat them as one big match).

Problem 2: How do I make it match across multilines? I know the . character doesn't allow for new line characters, but I'm using the /m modifier (which doesn't seem to work).

Any ideas would be appreciated!

Thanks.

Upvotes: 0

Views: 53

Answers (2)

SeriousDron
SeriousDron

Reputation: 1346

For problem 2. There is no DOT_ALL modificator in js. But use can use construction [\s\S] instead of dot that actually match all symbols. So finally you regexp will be 

/<\!--\s*?DEL\s*?-->([\s\S]*?)<\!--\s*?\/DEL\s*?-->/gm

Upvotes: 1

Ryen Nelsen
Ryen Nelsen

Reputation: 387

Problem 1

You just need to make your wildcard lazy too:

template = template.replace(/<\!--\s*?DEL\s*?-->(.*?)<\!--\s*?\/DEL\s*?-->/gm, "");
template = template.replace(/<\!--\s*?ADD\s*?-->(.*?)<\!--\s*?\/ADD\s*?-->/gm, "$1");

Upvotes: 1

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