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diff --git a/together/node_modules/once/README.md b/together/node_modules/once/README.md deleted file mode 100644 index 1f1ffca..0000000 --- a/together/node_modules/once/README.md +++ /dev/null @@ -1,79 +0,0 @@ -# once - -Only call a function once. - -## usage - -```javascript -var once = require('once') - -function load (file, cb) { - cb = once(cb) - loader.load('file') - loader.once('load', cb) - loader.once('error', cb) -} -``` - -Or add to the Function.prototype in a responsible way: - -```javascript -// only has to be done once -require('once').proto() - -function load (file, cb) { - cb = cb.once() - loader.load('file') - loader.once('load', cb) - loader.once('error', cb) -} -``` - -Ironically, the prototype feature makes this module twice as -complicated as necessary. - -To check whether you function has been called, use `fn.called`. Once the -function is called for the first time the return value of the original -function is saved in `fn.value` and subsequent calls will continue to -return this value. - -```javascript -var once = require('once') - -function load (cb) { - cb = once(cb) - var stream = createStream() - stream.once('data', cb) - stream.once('end', function () { - if (!cb.called) cb(new Error('not found')) - }) -} -``` - -## `once.strict(func)` - -Throw an error if the function is called twice. - -Some functions are expected to be called only once. Using `once` for them would -potentially hide logical errors. - -In the example below, the `greet` function has to call the callback only once: - -```javascript -function greet (name, cb) { - // return is missing from the if statement - // when no name is passed, the callback is called twice - if (!name) cb('Hello anonymous') - cb('Hello ' + name) -} - -function log (msg) { - console.log(msg) -} - -// this will print 'Hello anonymous' but the logical error will be missed -greet(null, once(msg)) - -// once.strict will print 'Hello anonymous' and throw an error when the callback will be called the second time -greet(null, once.strict(msg)) -``` |