How to pipe YAML into EJS in a Gulp stream? - stream

Question

I'm using gulp.js. I want to pipe the resulting JSON data from gulp-yaml, straight into gulp-ejs. My logic says that I'm probably going to have to get synchronous at some point?
What I have tried thus far:
var yaml = require('gulp-yaml');
var ejs = require('gulp-ejs');
gulp.task('yaml', function(){
return gulp.src('./path/to/template.ejs')
.pipe( ejs( gulp.src('./path/to/data.yml').pipe( yaml() ) ) )
.pipe(gulp.dest('./path/to/dest'));
});
I realise that the above is an idiotic script as I'm essentially trying to pass a stream as an argument to ejs. And as predicted, it doesn't work. I've tried numerous other things but I'm guessing someone has done this before?
I reckon gulp-data will have something to do with the solution...

Answer 1

You probably don't need the gulp-data plugin to achieve this; like you said you're just passing the option synchronously to the ejs plugin, and you're only needing the one yaml config file. So this is probably better:
var yaml = require('js-yaml');
var ejs = require('gulp-ejs');
var fs = require('fs');
gulp.task('ejs-with-yaml', function () {
return gulp.src('path/to/template.ejs')
.pipe(ejs(yaml.safeLoad(fs.readFileSync('path/to/data.yml', 'utf-8'))))
.pipe(gulp.dest('path/to/dest'));
});

Answer 2

Okay, so after a bit of head-scratching I've been able to find a solution using js-yaml and gulp-data.
var yaml = require('js-yaml');
var ejs = require('gulp-ejs');
var data = require('gulp-data');
gulp.task('ejs-with-yaml', function(){
return gulp.src('path/to/data.yml'))
.pipe(data(function(file, cb){
// throughput the stream in case of bad/absent file data
if (file.isNull()) return cb( null, file );
if (file.isStream()) return cb( new Error("Streaming not supported") );
// try and convert yaml to json
try {
json = yaml.load(String(file.contents.toString('utf8')));
} catch(e) {
console.log(e);
}
gulp.src('path/to/template.ejs').pipe(ejs(json)).pipe(gulp.dest( 'path/to/dest' ));
}));
});
Hopefully this might help others that are stuck on this. If anyone has a better solution, feel free to comment.