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Diffstat (limited to 'middleware/node_modules/ee-first/index.js')
-rw-r--r-- | middleware/node_modules/ee-first/index.js | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/middleware/node_modules/ee-first/index.js b/middleware/node_modules/ee-first/index.js new file mode 100644 index 0000000..501287c --- /dev/null +++ b/middleware/node_modules/ee-first/index.js @@ -0,0 +1,95 @@ +/*! + * ee-first + * Copyright(c) 2014 Jonathan Ong + * MIT Licensed + */ + +'use strict' + +/** + * Module exports. + * @public + */ + +module.exports = first + +/** + * Get the first event in a set of event emitters and event pairs. + * + * @param {array} stuff + * @param {function} done + * @public + */ + +function first(stuff, done) { + if (!Array.isArray(stuff)) + throw new TypeError('arg must be an array of [ee, events...] arrays') + + var cleanups = [] + + for (var i = 0; i < stuff.length; i++) { + var arr = stuff[i] + + if (!Array.isArray(arr) || arr.length < 2) + throw new TypeError('each array member must be [ee, events...]') + + var ee = arr[0] + + for (var j = 1; j < arr.length; j++) { + var event = arr[j] + var fn = listener(event, callback) + + // listen to the event + ee.on(event, fn) + // push this listener to the list of cleanups + cleanups.push({ + ee: ee, + event: event, + fn: fn, + }) + } + } + + function callback() { + cleanup() + done.apply(null, arguments) + } + + function cleanup() { + var x + for (var i = 0; i < cleanups.length; i++) { + x = cleanups[i] + x.ee.removeListener(x.event, x.fn) + } + } + + function thunk(fn) { + done = fn + } + + thunk.cancel = cleanup + + return thunk +} + +/** + * Create the event listener. + * @private + */ + +function listener(event, done) { + return function onevent(arg1) { + var args = new Array(arguments.length) + var ee = this + var err = event === 'error' + ? arg1 + : null + + // copy args to prevent arguments escaping scope + for (var i = 0; i < args.length; i++) { + args[i] = arguments[i] + } + + done(err, ee, event, args) + } +} |