gulp-subset-process

Process a subset of the stream and put the result into place. When order matters.

Install

npm install gulp-subset-process --save-dev

Description

Say, you need to do something with a subset of the stream and you need to put the result into place of first occurrence of a file of your subset in the stream (or last occurrence, or leave all occurrences in the same places). That's what this plugin do.

Examples

var subsetProcess = require('gulp-subset-process');
 
 
gulp.task('some-task', function() {
    return gulp.src(['file1.js', 'file2.txt', 'file3.css', 'file4.txt', 'file5.png'])
        .pipe(subsetProcess('**/*.txt', function(src) { return src; }));
    // We did nothing with a subset, resulting stream is:
    // ['file1.js', 'file2.txt', 'file4.txt', 'file3.css', 'file5.png']
});
 
 
gulp.task('some-task2', function() {
    return gulp.src(['file1.js', 'file2.txt', 'file3.css', 'file4.txt', 'file5.png'])
        .pipe(subsetProcess(
            '**/*.txt',
            function(src) { return src; },
            {occurrence: 'last'} // Insert the result after last occurrence of `**/*.txt` in the stream.
        ));
    // ['file1.js', 'file3.css', 'file2.txt', 'file4.txt', 'file5.png']
});
 
 
gulp.task('some-task3', function() {
    return gulp.src(['file1.js', 'file2.txt', 'file3.css', 'file4.txt', 'file5.png'])
        .pipe(subsetProcess('**/*.txt', function(src) { return src.pipe(concat('all.txt')); }));
    // ['file1.js', 'all.txt', 'file3.css', 'file5.png']
});
 
 
gulp.task('some-task4', function() {
    return gulp.src(['file1.js', 'file2.txt', 'file3.css', 'file4.txt', 'file5.png'])
        .pipe(subsetProcess(
            '**/*.txt',
            function(src) { return src.pipe(template({env: 'piu'})); },
            {occurrence: 'keep'} // Keep positions in the stream.
        ));
    // ['file1.js', 'file2.txt', 'file3.css', 'file4.txt', 'file5.png']
});

API

subsetProcess(pattern, subtask, options)

Returns processed stream.

pattern (String or Array)

Accepts a string/array with globbing patterns which are run through multimatch.

subtask (Function)

Callback, first argument is a stream with a subset of initial stream matching pattern.

options (Object)

Accepts minimatch options and occurrence option with 'first' (default), 'last' and 'keep' values to insert the result in place of first occurrence of a file of your subset, in place of last occurrence or keep all occurrences.