action_cable for wx

action_cable_wx.js

class Cable {
  constructor(options) {
    this.options = options || {}
    this.polled = 0
    wx.onSocketOpen(() => {
      if (this.options.connected) {
        this.options.connected()
      }
      this.resubscribe()
      this.stopPolling()
      this.polled = 0
    })
    wx.onSocketError(() => {
      this.startPolling()
    })
    wx.onSocketClose(() => {
      if (this.options.disconnected) {
        this.options.disconnected()
      }
      this.startPolling()
    })
    wx.onSocketMessage(res => {
      let data = JSON.parse(res.data)
      let subscription = this.subscriptions[data.identifier]
      if (subscription) subscription.received(data)
    })
  }

  connect(url) {
    this.options.url = url || this.options.url
    wx.connectSocket({
      url: this.options.url
    })
  }

  startPolling() {
    this.stopPolling()
    this.poll()
  }

  stopPolling() {
    clearTimeout(this.pollTimeout)
  }

  poll() {
    this.polled++
    this.pollTimeout = setTimeout(() => {
      this.connect()
    }, Math.min(2000, 500 * this.polled));
  }

  subscriptions = {}

  subscribe(info, options) {
    let identifier = JSON.stringify(info)
    let subscription = new Subscription(identifier, options)
    this.subscriptions[identifier] = subscription
    subscription.sendCommand('subscribe')
    subscription.unsubscribe = () => {
      subscription.sendCommand('unsubscribe');
      this.subscriptions[identifier] = null
      delete this.subscriptions[identifier]
    }
    return subscription
  }

  resubscribe() {
    for (let identifier in this.subscriptions) {
      let subscription = this.subscriptions[identifier]
      if (subscription) {
        subscription.sendCommand('subscribe')
      }
    }
  }
}

class Subscription {
  constructor(identifier, options) {
    this.identifier = identifier
    this.options = options
  }

  sendCommand(command, data) {
    let content = {
      command: command,
      identifier: this.identifier
    }
    if (data) content.data = data;
    wx.sendSocketMessage({ data: JSON.stringify(content) })
  }

  unsubscribe() {}

  send(content) {
    this.sendCommand('message', JSON.stringify(content))
  }

  received(data) {
    if (data.type === 'confirm_subscription' && this.options.subscribed) {
      this.options.subscribed()
    } else if (this.options.received) {
      this.options.received(data.message);
    }
  }
}

module.exports = Cable