make-transform
Make simple string based functions into browserify transforms. This does not return anything like a true stream and, as a result, is very small to browserify.
The objective was to implement just the API needed to support:
- using it as a browserify transform
process.stdin.pipe(transform).pipe(process.stdout)
fs.createReadStream('input.js').pipe(transform).pipe(process.stdout)
process.stdin.pipe(transform).pipe(fs.createWriteStream('output.js'))
fs.createReadStream('input.js').pipe(transform).pipe(fs.createWriteStream('output.js'))
In short, this is a helper for when you are forced to interface with streams by factors outside your controll, but the actual API is just processing strings (a far simpler abstraction).
Installation
npm install make-transform
API
makeTransform(fn(filename, source))
Make a browserify transform out of a function which takes filename
and source
as arguments and returns a string.
If a source
argument is provided when called, it will just pass through to fn.
Example:
var makeTransform = require('make-transform')
module.exports = makeTransform(function (file, source) {
return source.toLowerCase()
})
var res = module.exports('file.js', 'FUNCTION (STR) { RETURN STR.SPLIT("") }')
// res => 'function (str) { return str.split("") }'
var strm = module.exports('file.js')
strm.end('FUNCTION (STR) { RETURN STR.SPLIT("") }')
strm.pipe(concat(function (res) {
// res => 'function (str) { return str.split("") }'
}))
makeTransform.async(fn(filename, source, callback))
Make a browserify transform out of a function which takes filename
, source
and callback
as arguments and calls the callback with an optional error and a string.
If a source
argument and callback
is provided when called, it will just pass through to fn.
Example:
var makeTransform = require('make-transform')
module.exports = makeTransform.async(function (file, source, callback) {
callback(null, source.toLowerCase())
})
module.exports('file.js', 'FUNCTION (STR) { RETURN STR.SPLIT("") }', function (err, res) {
// res => 'function (str) { return str.split("") }'
})
var strm = module.exports('file.js')
strm.end('FUNCTION (STR) { RETURN STR.SPLIT("") }')
strm.pipe(concat(function (res) {
// res => 'function (str) { return str.split("") }'
}))
Promises
Promise support was ommitted in an effor to keep this library ludicrously small. It's easy enough to make your own "promise transform" though:
var makeTransform = require('make-transform')
var Promise = require('promise')
function transform(file, source) {
// return a promise for a string here
}
var streaming = makeTransform.async(Promise.nodeify(transform))
module.exports = streaming
module.exports.promise = transform
License
MIT