Question

我是firefox sdk的新手，在google上学习我试图从数组中的每个循环推送字符串并稍后读取它但阵列仍然是空的。

require("sdk/ui/button/action").ActionButton({
  id: "list-tabs",
  label: "List Tabs",
  icon: "./32.png",
  onClick: CollectURLs
});


function CollectURLs(){
    var tabs = require("sdk/tabs");
    var links = [];
    for each (var tab in tabs){
        if(tab.url.indexOf('google.com') != '-1'){
            tab.attach({
                    contentScript: 'for (var i = 0; i < document.getElementsByTagName("h3").length ; i= i+1){'+
                    'self.postMessage(document.getElementsByTagName("h3")[i].getElementsByTagName("a")[0].getAttribute(\'href\'));'+
                    '}',
                    onMessage: function(message) {
                        console.log("URL: "+message);
                        links.push(message);
                    }               
            });
        }
    }
    console.log("ALL URLS:"+links);
}

输出：

C:\addon-sdk\bin\hello>cfx run
Using binary at 'C:\Program Files (x86)\Mozilla Firefox\firefox.exe'.
Using profile at 'c:\users\admin\appdata\local\temp\tmpp62fgl.mozrunner'.
JavaScript error: chrome://browser/content/urlbarBindings.xml, line 674: aUrl is undefined
console.log: hello: ALL URLS:
console.log: hello: URL: http://www.aa.com/
console.log: hello: URL: http://www.aa.org/
console.log: hello: URL: http://www.aaschool.ac.uk/
console.log: hello: URL: http://www.theaa.com/route-planner/
console.log: hello: URL: http://www.theaa.com/
console.log: hello: URL: http://www.aa.co.nz/
console.log: hello: URL: http://www.theaa.ie/
console.log: hello: URL: http://finance.yahoo.com/q?s=AA
console.log: hello: URL: http://www.alcoholics-anonymous.org.uk/
console.log: hello: URL: http://en.wikipedia.org/wiki/AA

并且有这个数组 console.log：你好：所有URL：它是空的，并在循环结束前打印出来

Answer 1

看起来您需要使用事件系统在内容脚本和附加组件之间进行通信。阅读＆＃39;与附加组件进行通信＆＃39;部分在这里： https://developer.mozilla.org/en-US/Add-ons/SDK/Guides/Content_Scripts

from their docs

我认为您的代码变为（未经测试）：

require("sdk/ui/button/action").ActionButton({
  id: "list-tabs",
  label: "List Tabs",
  icon: "./32.png",
  onClick: CollectURLs
});
//moved these out of the method
var tabs = require("sdk/tabs");
var self = require("sdk/self"); 


function CollectURLs(){
    var links = [];
    for each (var tab in tabs){
        if(tab.url.indexOf('google.com') != '-1'){
            worker = tab.attach({ //change here
                    contentScript: 'for (var i = 0; i < document.getElementsByTagName("h3").length ; i= i+1){'+
                    'self.postMessage(document.getElementsByTagName("h3")[i].getElementsByTagName("a")[0].getAttribute(\'href\'));'+
                    '}',
                    onMessage: function(message) {
                        //console.log("URL: "+message);
                        //links.push(message);
                        self.port.emit("url", message); //change here
                    }               
            });
            //change here
            worker.on("url", function(message) {
                links.push(message);
                console.log('current link list: ', links);
            });
        }
    }
    console.log("empty array expected because the event emitting is async:" + links);
}

无法从循环firefox addon sdk外部访问数组

1 个答案: