@eggjs/watcher

@eggjs/watcher

File watcher plugin for egg

Usage

In worker process:

app.watcher.watch(path, listener)

Start watching file(s).

• path(String|Array): file path(s)
• listener(Function): file change callback

app.watcher.unwatch(path[, listener])

Stop watching file(s).

• path(String|Array): file path(s)
• listener(Function): file change callback

In agent process:

agent.watcher.watch(path, listener)

Start watching file(s).

• path(String|Array): file path(s)
• listener(Function): file change callback

agent.watcher.unwatch(path[, listener])

Stop watching file(s).

• path(String|Array): file path(s)
• listener(Function): file change callback

Watching mode

development Mode

There's a built-in development mode which works in local(env is local). Once files on disk is modified it will emit a change event immediately.

Customize Watching Mode

Say we want to build a custom event source plugin (package name: egg-watcher-custom, eggPlugin.name: watcherCustom).

Firstly define our custom event source like this:

// {plugin_root}/lib/custom_event_source.js
import { Base } from 'sdk-base';

export default class CustomEventSource extends Base {
  // `opts` comes from app.config[${eventSourceName}]
  // `eventSourceName` will be registered later in
  // `config.watcher.eventSources` as the key shown below
  constructor(opts) {
    super(opts);
    this.ready(true);
  }

  watch(path) {
    // replace this with your desired way of watching,
    // when aware of any change, emit a `change` event
    // with an info object containing `path` property
    // specifying the changed directory or file.
    this._h = setInterval(() => {
      this.emit('change', { path });
    }, 1000);
  }

  unwatch() {
    // replace this with your implementation
    if (this._h) {
      clearInterval(this._h);
    }
  }
}

Event source implementations varies according to your running environment. When working with vagrant, docker, samba or such other non-standard way of development, you should use a different watch API specific to what you are working with.

Then add your custom event source to config:

// config/config.default.js
import CustomEventSource from '../lib/custom_event_source';

export default {
  watcher: {
    eventSources: {
      custom: CustomEventSource,
    },
  },
};

Choose to use your custom watching mode in your desired env.

// config/config.${env}.js

export default {
  watcher: {
    type: 'custom',
  },

  // this will pass to your CustomEventSource constructor as opts
  watcherCustom: {
    // foo: 'bar',
  },
};

If possible, plugins named like egg-watcher-${customName}(egg-watcher-vagrant eg.) are recommended.

Questions & Suggestions

Please open an issue here.

License

MIT

Contributors

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