CODEWITHSUNDEEP
javascriptnode.jsgulp
Evanss
Evanss

Reputation: 23593

Regex find and replace with gulp / node and use part of the find's string in the replace?

Im performing a find and replace with gulp.

I need to find this string below (ANYTHING can be anything, its not a string of 'ANYTHING'):

{% id_ANYTHING %}

And replace it with this: 

{% block ANYTHING %}{% endblock %}

Example1.

Replace this: 

{% id_page %}

With this: 

{% block page %}{% endblock %}

Example2.

Replace this: 

{% id_whatever %}

With this: 

{% block whatever %}{% endblock %}

Ive found the regex that I need to find the match. Im already using gulp-replace for a similar but simpler task so Ive started using it for this but I'm not sure how to grab the 'anything' value so that I can use it in the replace.

https://github.com/lazd/gulp-replace

replace = function() {
  return gulp.src('before.html')
    .pipe(replace({
      patterns:
        [{
          match: /{% id_.{2,99} %}/g,
          replacement: '{% block page %}{% endblock %}'
        }]
    }))
    .pipe(gulp.dest('after.html'));
},

Should I be looking to do this with Gulp or Node?

Upvotes: 1

Views: 1083

Answers (1)

peteb
peteb

Reputation: 19428

Per the docs for gulp-replace you can use a function for the replacement value, just like you can for String.prototype.replace()

Also, I've modified your RegEx to group the .{2,99} together using (). The String.replace() callback function will breakout each group as a separate arg. Since you're only interested in extracting that group, we can have String.replace() do all the work and return back the value to replace the matched text.

const gulp = require('gulp')
const replace = require('gulp-replace');
const path = require('path');
let pattern = new RegExp(/{% id_(.{2,99}) %}/, 'g');

gulp.task('replace', () => {
  return gulp.src('before.html')
    .pipe(replace(pattern, (match, p1) => {
      return `{% block ${p1} %} {% endblock %}`;
    }))
    .pipe(gulp.dest(path.join(__dirname, 'after.html')));
});

Upvotes: 2

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