javascript - onMessage 事件永远不会被调用

Question

所以我正在为 Firefox 开发我的下一个附加组件，但是，在阅读 ContextMenus 的文档时，似乎永远不会调用 onMessage 事件，这是我的代码:

exports.main = function(){
    var addonTab = require('addon-page');
    var data = require('self').data;
    var tabs = require('tabs');
    var cm = require("context-menu");

    cm.Item({
        label: "Tag This Image",
        context: cm.URLContext("*"),
        contextSelector: "img",
        contentScript: 
            'self.on("click", function(node, data){' +
            '   self.postMessage(node);' +
            '});',

        // nothing works...
        onMessage: function(node){
            openImageEditor(node.src);
            alert("Message? It worked? No way!"); 
            onTagImage(node);
        }
    });

    var onTagImage = function(node){
        alert("Image tagged!"); 
    };

    tabs.open({url: data.url('index.html'), isPinned:true});
};

所以我看了一下错误的控制台，但这可能是我见过的最糟糕的错误格式......

Timestamp: 14/07/2012 3:21:44 Error: An exception occurred. Traceback (most recent call last): File "resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/addon-kit/lib/context-menu.js", line 1310, in CMP_handleEvent this.handleClick(event.target); File "resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/addon-kit/lib/context-menu.js", line 1339, in CMP_handleClick this.browserWin.fireClick(topLevelItem, popupNode, item.data); File "resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/addon-kit/lib/context-menu.js", line 1162, in BW_fireClick worker.fireClick(popupNode, clickedItemData); File "resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/addon-kit/lib/context-menu.js", line 663, in CMW_fireClick this._contentWorker.emitSync("click", popupNode, clickedItemData); File "resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/api-utils/lib/content/worker.js", line 71, in emitSync return this._emitToContent(Array.slice(arguments)); File "resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/api-utils/lib/content/content-worker.js", line 96, in onChromeEvent return emit.apply(null, args); File "resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/api-utils/lib/content/content-worker.js", line 45, in onEvent results.push(callback.apply(null, args)); File "javascript:self.on("click", function(node, data){
self.postMessage(node);});", line 1, in null File "resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/api-utils/lib/content/content-worker.js", line 81, in onEvent let str = JSON.stringify(args, replacer); [Exception... "Component returned failure code: 0x80040111 (NS_ERROR_NOT_AVAILABLE) [nsIImageLoadingContent.loadingEnabled]" nsresult: "0x80040111 (NS_ERROR_NOT_AVAILABLE)" location: "JS frame :: resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/api-utils/lib/cuddlefish.js -> resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/api-utils/lib/sandbox.js -> resource://jid0-dxglsws2k0cubycbcn7cw5tcyqk-at-jetpack/api-utils/lib/content/content-worker.js :: onEvent :: line 81" data: no]

这是实际的行，但这对我来说没有任何意义:

File "javascript:self.on("click", function(node, data){self.postMessage(node);});", line 1, in null

问题:这个错误是什么意思，或者说的行到底有什么问题？

Answer 1

您的上下文菜单实现在某些方面有点古怪，请参见这个固定示例:

https://builder.addons.mozilla.org/addon/1065630/latest/

1. 内容脚本的postMessage调用不能发送html节点，只能发送JSON数据。

2. 不要在 main.js 或从 ./lib/加载的其他模块中使用警报 - 此处未定义警报。请改用 console.log。

3. 你需要的上下文是context: cm.SelectorContext('img')