Cordova模块注解
请先阅读channel模块的代码在阅读该模块
define("cordova", function(require, exports, module) {
// Workaround for Windows 10 in hosted environment case
// http://www.w3.org/html/wg/drafts/html/master/browsers.html#named-access-on-the-window-object
if (window.cordova && !(window.cordova instanceof HTMLElement)) {
throw new Error("cordova already defined");
}
var channel = require('cordova/channel');
var platform = require('cordova/platform');
/**
*保留浏览器自己的监听方法
*/
var m_document_addEventListener = document.addEventListener;
var m_document_removeEventListener = document.removeEventListener;
var m_window_addEventListener = window.addEventListener;
var m_window_removeEventListener = window.removeEventListener;
/**
*
* 存放我们自定义的事件
*/
var documentEventHandlers = {},
windowEventHandlers = {};
//添加监听器的时候如果documentEventHandlers上存在对应的channel则将事件添加在该channel上，没有则添加到浏览器自带的API上
document.addEventListener = function(evt, handler, capture) {
var e = evt.toLowerCase();
if (typeof documentEventHandlers[e] != 'undefined') {
documentEventHandlers[e].subscribe(handler);
} else {
m_document_addEventListener.call(document, evt, handler, capture);
}
};
window.addEventListener = function(evt, handler, capture) {
var e = evt.toLowerCase();
if (typeof windowEventHandlers[e] != 'undefined') {
windowEventHandlers[e].subscribe(handler);
} else {
m_window_addEventListener.call(window, evt, handler, capture);
}
};
document.removeEventListener = function(evt, handler, capture) {
var e = evt.toLowerCase();
// If unsubscribing from an event that is handled by a plugin
if (typeof documentEventHandlers[e] != "undefined") {
documentEventHandlers[e].unsubscribe(handler);
} else {
m_document_removeEventListener.call(document, evt, handler, capture);
}
};
window.removeEventListener = function(evt, handler, capture) {
var e = evt.toLowerCase();
// If unsubscribing from an event that is handled by a plugin
if (typeof windowEventHandlers[e] != "undefined") {
windowEventHandlers[e].unsubscribe(handler);
} else {
m_window_removeEventListener.call(window, evt, handler, capture);
}
};
//创建事件，参数2做为携带的数据添加到事件对象上
function createEvent(type, data) {
var event = document.createEvent('Events');
event.initEvent(type, false, false);
if (data) {
for (var i in data) {
if (data.hasOwnProperty(i)) {
event[i] = data[i];
}
}
}
return event;
}
var cordova = {
define:define,
require:require,
version:PLATFORM_VERSION_BUILD_LABEL,
platformVersion:PLATFORM_VERSION_BUILD_LABEL,
platformId:platform.id,
/**
* Methods to add/remove your own addEventListener hijacking on document + window.
*/
addWindowEventHandler:function(event) {
return (windowEventHandlers[event] = channel.create(event));
},
addStickyDocumentEventHandler:function(event) {
return (documentEventHandlers[event] = channel.createSticky(event));
},
addDocumentEventHandler:function(event) {
return (documentEventHandlers[event] = channel.create(event));
},
removeWindowEventHandler:function(event) {
delete windowEventHandlers[event];
},
removeDocumentEventHandler:function(event) {
delete documentEventHandlers[event];
},
/**
* 返回原始的监听器方法
*
* @return object
*/
getOriginalHandlers: function() {
return {'document': {'addEventListener': m_document_addEventListener, 'removeEventListener': m_document_removeEventListener},
'window': {'addEventListener': m_window_addEventListener, 'removeEventListener': m_window_removeEventListener}};
},
/**
* 触发type类型事件，如果documentEventHandlers上已经有该类型事件的channel的调用channel的fire方法来触发该channel，
* subscribe的所有事件。如果documentEventHandlers没有该类型事件channel，则执行绑定到浏览器上的事件
*/
fireDocumentEvent: function(type, data, bNoDetach) {
var evt = createEvent(type, data);
if (typeof documentEventHandlers[type] != 'undefined') {
if( bNoDetach ) {
documentEventHandlers[type].fire(evt);
}
else {
setTimeout(function() {
// Fire deviceready on listeners that were registered before cordova.js was loaded.
if (type == 'deviceready') {
document.dispatchEvent(evt);
}
documentEventHandlers[type].fire(evt);
}, 0);
}
} else {
//派发事件，将触发对应type addEventListener(type,lisntener,false) 的listener方法
document.dispatchEvent(evt);
}
},
fireWindowEvent: function(type, data) {
var evt = createEvent(type,data);
if (typeof windowEventHandlers[type] != 'undefined') {
setTimeout(function() {
windowEventHandlers[type].fire(evt);
}, 0);
} else {
window.dispatchEvent(evt);
}
},
/**
* Plugin callback mechanism.
*/
// Randomize the starting callbackId to avoid collisions after refreshing or navigating.
// This way, it's very unlikely that any new callback would get the same callbackId as an old callback.
callbackId: Math.floor(Math.random() * 2000000000),
callbacks: {},
callbackStatus: {
NO_RESULT: 0,
OK: 1,
CLASS_NOT_FOUND_EXCEPTION: 2,
ILLEGAL_ACCESS_EXCEPTION: 3,
INSTANTIATION_EXCEPTION: 4,
MALFORMED_URL_EXCEPTION: 5,
IO_EXCEPTION: 6,
INVALID_ACTION: 7,
JSON_EXCEPTION: 8,
ERROR: 9
},
/**
* Called by native code when returning successful result from an action.
*/
callbackSuccess: function(callbackId, args) {
cordova.callbackFromNative(callbackId, true, args.status, [args.message], args.keepCallback);
},
/**
* Called by native code when returning error result from an action.
*/
callbackError: function(callbackId, args) {
// TODO: Deprecate callbackSuccess and callbackError in favour of callbackFromNative.
// Derive success from status.
cordova.callbackFromNative(callbackId, false, args.status, [args.message], args.keepCallback);
},
/**
* 该方法由原生调用，我们在执行exec的时候将回调函数添加到 cordova.callbacks[callbackId]上，
* 原生执行完插件后在使用webview.evaluateJavascript('cordova.callbackFromNative(callbackId,successData,failData)')方法
* 在调用我们绑定的回调函数
*/
callbackFromNative: function(callbackId, isSuccess, status, args, keepCallback) {
try {
var callback = cordova.callbacks[callbackId];
if (callback) {
if (isSuccess && status == cordova.callbackStatus.OK) {
callback.success && callback.success.apply(null, args);
} else if (!isSuccess) {
callback.fail && callback.fail.apply(null, args);
}
/*
else
Note, this case is intentionally not caught.
this can happen if isSuccess is true, but callbackStatus is NO_RESULT
which is used to remove a callback from the list without calling the callbacks
typically keepCallback is false in this case
*/
// Clear callback if not expecting any more results
if (!keepCallback) {
delete cordova.callbacks[callbackId];
}
}
}
catch (err) {
var msg = "Error in " + (isSuccess ? "Success" : "Error") + " callbackId: " + callbackId + " : " + err;
console && console.log && console.log(msg);
cordova.fireWindowEvent("cordovacallbackerror", { 'message': msg });
throw err;
}
},
addConstructor: function(func) {
channel.onCordovaReady.subscribe(function() {
try {
func();
} catch(e) {
console.log("Failed to run constructor: " + e);
}
});
}
};
module.exports = cordova;
});