# glob-watcher [![NPM version][npm-image]][npm-url] [![Downloads][downloads-image]][npm-url] [![Build Status][travis-image]][travis-url] [![AppVeyor Build Status][appveyor-image]][appveyor-url] [![Coveralls Status][coveralls-image]][coveralls-url] [![Gitter chat][gitter-image]][gitter-url] Watch globs and execute a function upon change, with intelligent defaults for debouncing and queueing. ## Usage ```js var watch = require('glob-watcher'); watch(['./*.js', '!./something.js'], function(done){ // This function will be called each time a globbed file is changed // but is debounced with a 200ms delay (default) and queues subsequent calls // Make sure to signal async completion with the callback // or by returning a stream, promise, observable or child process done(); // if you need access to the `path` or `stat` object, listen // for the `change` event (see below) // if you need to listen to specific events, use the returned // watcher instance (see below) }); // Raw chokidar instance var watcher = watch(['./*.js', '!./something.js']); // Listen for the 'change' event to get `path`/`stat` // No async completion available because this is the raw chokidar instance watcher.on('change', function(path, stat) { // `path` is the path of the changed file // `stat` is an `fs.Stat` object (not always available) }); // Listen for other events // No async completion available because this is the raw chokidar instance watcher.on('add', function(path, stat) { // `path` is the path of the changed file // `stat` is an `fs.Stat` object (not always available) }); ``` ## API ### `watch(globs[, options][, fn])` Takes a path string, an array of path strings, a [glob][micromatch] string or an array of [glob][micromatch] strings as `globs` to watch on the filesystem. Also optionally takes `options` to configure the watcher and a `fn` to execute when a file changes. __Note: As of 5.0.0, globs must use `/` as the separator character because `\\` is reserved for escape sequences (as per the Bash 4.3 & Micromatch specs). This means you can't use `path.join()` or `__dirname` in Windows environments. If you need to use `path.join()`, you can use [normalize-path][normalize-path] against your paths afterwards. If you need to use `__dirname`, you can set it as the `cwd` option that gets passed directly to [chokidar][chokidar]. The [micromatch docs][micromatch-backslashes] contain more information about backslashes.__ Returns an instance of [chokidar][chokidar]. #### `fn([callback])` If the `fn` is passed, it will be called when the watcher emits a `change`, `add` or `unlink` event. It is automatically debounced with a default delay of 200 milliseconds and subsequent calls will be queued and called upon completion. These defaults can be changed using the `options`. The `fn` is passed a single argument, `callback`, which is a function that must be called when work in the `fn` is complete. Instead of calling the `callback` function, [async completion][async-completion] can be signalled by: * Returning a `Stream` or `EventEmitter` * Returning a `Child Process` * Returning a `Promise` * Returning an `Observable` Once async completion is signalled, if another run is queued, it will be executed. #### `options` ##### `options.ignoreInitial` If set to `false` the `fn` is called during [chokidar][chokidar] instantiation as it discovers the file paths. Useful if it is desirable to trigger the `fn` during startup. __Passed through to [chokidar][chokidar], but defaulted to `true` instead of `false`.__ Type: `Boolean` Default: `true` ##### `options.delay` The delay to wait before triggering the `fn`. Useful for waiting on many changes before doing the work on changed files, e.g. find-and-replace on many files. Type: `Number` Default: `200` (milliseconds) ##### `options.queue` Whether or not a file change should queue the `fn` execution if the `fn` is already running. Useful for a long running `fn`. Type: `Boolean` Default: `true` ##### `options.events` An event name or array of event names to listen for. Useful if you only need to watch specific events. Type: `String | Array` Default: `[ 'add', 'change', 'unlink' ]` ##### other Options are passed directly to [chokidar][chokidar]. ## License MIT [micromatch]: https://github.com/micromatch/micromatch [normalize-path]: https://www.npmjs.com/package/normalize-path [micromatch-backslashes]: https://github.com/micromatch/micromatch#backslashes [async-completion]: https://github.com/gulpjs/async-done#completion-and-error-resolution [chokidar]: https://github.com/paulmillr/chokidar [downloads-image]: http://img.shields.io/npm/dm/glob-watcher.svg [npm-url]: https://npmjs.com/package/glob-watcher [npm-image]: http://img.shields.io/npm/v/glob-watcher.svg [travis-url]: https://travis-ci.org/gulpjs/glob-watcher [travis-image]: http://img.shields.io/travis/gulpjs/glob-watcher.svg?label=travis-ci [appveyor-url]: https://ci.appveyor.com/project/gulpjs/glob-watcher [appveyor-image]: https://img.shields.io/appveyor/ci/gulpjs/glob-watcher.svg?label=appveyor [coveralls-url]: https://coveralls.io/r/gulpjs/glob-watcher [coveralls-image]: http://img.shields.io/coveralls/gulpjs/glob-watcher/master.svg [gitter-url]: https://gitter.im/gulpjs/gulp [gitter-image]: https://badges.gitter.im/gulpjs/gulp.png