How to use objects list as gulp source stream

Question

I know that gulp require a vinyl source stream to work properly, but is there an easy way to use an already existant vinyl file or a json object instead of the well known gulp.src that only takes globs?

Answer 1

After several researches I did not found any good solution for that problem so I decided to share my solution with you.

That problem is solved in 2 steps

1: You need to convert what ever you want to pipe in gulp to a vinyl file. This can be done like so

const Vinyl = require('vinyl');
var vinyl = new Vinyl();
vinyl.cwd = '/';
vinyl.base = '/';
vinyl.path = '/yourfictivefilepath';
vinyl.contents = new Buffer(JSON.stringify(yourobject));

For more information about that step: https://github.com/gulpjs/vinyl

2: Create a stream out of your vinyl files

I found that those steps can be repetitive and can make code less readable so I decided to encapsulate those steps in an npm package that does this for you.

https://www.npmjs.com/package/gulp-to-stream

Answer 2

Since gulp uses vinyl files as input and actually uses some of its properties(such as .base), it's inevitable to create vinyl files to make use of gulp. So I recommend this access to achieve your goal:

'use strict';
const gulp = require('gulp');
const header = require('gulp-header');//https://www.npmjs.com/package/gulp-header

gulp.task('default', function () {
    gulp.src("a.json")//empty file
        .pipe(header(JSON.stringify({a:1,b:2})))//inject your own content
        .pipe(gulp.dest("dist/"))
});

Create a empty file a.json and use it as source. Then inject your own content with gulp-header and do whatever you want with it.

If you want to avoid extra files(a.json), try this:

'use strict';
const gulp = require('gulp');
const transform = require('gulp-transform');
const rename = require("gulp-rename");

gulp.task('default', function () {
    return gulp.src("./gulpfile.js")
        .pipe(transform(() => JSON.stringify({a:1,b:2})))
        .pipe(rename("a.json"))
        .pipe(gulp.dest("dist/"))
});