tauri-workspace/cli/tauri.js/templates/tauri.js

// polyfills
if (!String.prototype.startsWith) {
  String.prototype.startsWith = function (searchString, position) {
    position = position || 0
    return this.substr(position, searchString.length) === searchString
  }
}

(function () {
  function webviewBind (name) {
    var RPC = window._rpc = (window._rpc || { nextSeq: 1 });
    window[name] = function () {
      var seq = RPC.nextSeq++;
      var promise = new Promise(function (resolve, reject) {
        RPC[seq] = {
          resolve: resolve,
          reject: reject,
        };
      });
      window.external.invoke(JSON.stringify({
        id: seq,
        method: name,
        params: Array.prototype.slice.call(arguments),
      }));
      return promise;
    }
  }
  if (!window.__TAURI_INVOKE_HANDLER__) {
    webviewBind('__TAURI_INVOKE_HANDLER__')
  }

  function s4() {
    return Math.floor((1 + Math.random()) * 0x10000)
      .toString(16)
      .substring(1)
  }

  var uid = function () {
    return s4() + s4() + '-' + s4() + '-' + s4() + '-' +
      s4() + '-' + s4() + s4() + s4()
  }

  function ownKeys(object, enumerableOnly) {
    var keys = Object.keys(object);
    if (Object.getOwnPropertySymbols) {
      var symbols = Object.getOwnPropertySymbols(object);
      if (enumerableOnly) symbols = symbols.filter(function (sym) {
        return Object.getOwnPropertyDescriptor(object, sym).enumerable;
      });
      keys.push.apply(keys, symbols);
    }
    return keys;
  }

  function _objectSpread(target) {
    for (var i = 1; i < arguments.length; i++) {
      var source = arguments[i] != null ? arguments[i] : {};
      if (i % 2) {
        ownKeys(source, true).forEach(function (key) {
          _defineProperty(target, key, source[key]);
        });
      } else if (Object.getOwnPropertyDescriptors) {
        Object.defineProperties(target, Object.getOwnPropertyDescriptors(source));
      } else {
        ownKeys(source).forEach(function (key) {
          Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key));
        });
      }
    }
    return target;
  }

  function _defineProperty(obj, key, value) {
    if (key in obj) {
      Object.defineProperty(obj, key, {
        value: value,
        enumerable: true,
        configurable: true,
        writable: true
      });
    } else {
      obj[key] = value;
    }
    return obj;
  }

  if (!window.__TAURI__) {
    window.__TAURI__ = {}
  }

  window.__TAURI__.transformCallback = function transformCallback(callback, once) {
    var identifier = uid()

    window[identifier] = function (result) {
      if (once) {
        delete window[identifier]
      }

      return callback && callback(result)
    }

    return identifier;
  }

  window.__TAURI__.promisified = function promisified(args) {
    var _this = this

    return new Promise(function (resolve, reject) {
      var callback = _this.transformCallback(function (r) {
        resolve(r)
        delete window[error]
      }, true)
      var error = _this.transformCallback(function (e) {
        reject(e)
        delete window[callback]
      }, true)

      window.__TAURI_INVOKE_HANDLER__(_objectSpread({
        callback: callback,
        error: error
      }, args))
    })
  }

  window.__TAURI__.loadAsset = function loadAsset(assetName, assetType) {
    return this.promisified({
      cmd: 'loadAsset',
      asset: assetName,
      assetType: assetType || 'unknown'
    })
  }

  document.addEventListener('error', function (e) {
    var target = e.target
    while (target != null) {
      if (target.matches ? target.matches('img') : target.msMatchesSelector('img')) {
        window.__TAURI__.loadAsset(target.src, 'image')
          .then(function (img) {
            target.src = img
          })
        break
      }
      target = target.parentElement
    }
  }, true)

  // open <a href="..."> links with the Tauri API
  function __openLinks() {
    document.querySelector('body').addEventListener('click', function (e) {
      var target = e.target
      while (target != null) {
        if (target.matches ? target.matches('a') : target.msMatchesSelector('a')) {
          if (target.href && target.href.startsWith('http') && target.target === '_blank') {
            window.__TAURI_INVOKE_HANDLER__({
              cmd: 'open',
              uri: target.href
            })
            e.preventDefault()
          }
          break
        }
        target = target.parentElement
      }
    }, true)
  }

  if (document.readyState === 'complete' || document.readyState === 'interactive') {
    __openLinks()
  } else {
    window.addEventListener('DOMContentLoaded', function () {
      __openLinks()
    }, true)
  }

  let permissionSettable = false
  let permissionValue = 'default'

  function isPermissionGranted() {
    if (window.Notification.permission !== 'default') {
      return Promise.resolve(window.Notification.permission === 'granted')
    }
    return window.__TAURI__.promisified({
      cmd: 'isNotificationPermissionGranted'
    })
  }

  function setNotificationPermission(value) {
    permissionSettable = true
    window.Notification.permission = value
    permissionSettable = false
  }

  function requestPermission() {
    return window.__TAURI__.promisified({
      cmd: 'requestNotificationPermission'
    }).then(function (permission) {
      setNotificationPermission(permission)
      return permission
    })
  }

  function sendNotification(options) {
    if (typeof options === 'object') {
      Object.freeze(options)
    }

    isPermissionGranted()
      .then(function (permission) {
        if (permission) {
          return window.__TAURI__.promisified({
            cmd: 'notification',
            options: typeof options === 'string' ? {
              title: options
            } : options
          })
        }
      })
  }

  window.Notification = function (title, options) {
    var opts = options || {}
    sendNotification(Object.assign(opts, {
      title: title
    }))
  }

  window.Notification.requestPermission = requestPermission

  Object.defineProperty(window.Notification, 'permission', {
    enumerable: true,
    get: function () {
      return permissionValue
    },
    set: function (v) {
      if (!permissionSettable) {
        throw new Error('Readonly property')
      }
      permissionValue = v
    }
  })

  isPermissionGranted()
    .then(function (response) {
      if (response === null) {
        setNotificationPermission('default')
      } else {
        setNotificationPermission(response ? 'granted' : 'denied')
      }
    })
})()