javascript - Firefox附加页面显示事件在工作人员能够接收消息之前触发

我正在编写一个firefox插件，并在数组中跟踪每个页面的工作程序。除了管理此阵列所需的一些花哨的工作（如此处https://bugzilla.mozilla.org/show_bug.cgi?id=686035和此处Addon SDK - context-menu and page-mod workers中所述）之外，所有其他组件都可以正常工作。我遇到的一个问题是，当侦听tabs pageshow事件（或工作人员自己的pageshow事件）时，回调似乎在工作人员实际准备就绪之前就触发了。当在回调中检索页面的相应工作程序并将其用于尝试将消息发送到内容脚本时，我收到错误消息The page is currently hidden and can no longer be used until it is visible again.通常，我只是使用setTimeout并咬紧牙关，但这不是。可用于附件。什么是合适的解决方法？附件主要部分的代码如下：

var { ToggleButton } = require('sdk/ui/button/toggle');
var panels = require('sdk/panel');
var tabs = require('sdk/tabs');
var self = require('sdk/self');
var pageMods = require('sdk/page-mod');
var ss = require('sdk/simple-storage');
var workers = [];

ss.storage.isPluginActive = ss.storage.isPluginActive || false;

var button = ToggleButton({
    id: 'tomorrowww',
    label: 'Tomorowww',
    icon: {
        '16': './icon-16.png',
        '32': './icon-32.png',
        '64': './icon-64.png'
    },
    onChange: handleButtonChange
});

var panel = panels.Panel({
    contentURL: self.data.url('panel.html'),
    contentScriptFile: self.data.url('panel-script.js'),
    onHide: handlePanelHide,
    width: 342,
    height: 270
});

panel.port.on('panel-ready', handlePanelReady);
panel.port.on('plugin-toggled', handlePluginToggled);
panel.port.on('link-clicked', handleLinkClicked);

pageMods.PageMod({
    include: ['*'],
    contentScriptFile: [self.data.url('CancerDOMManager.js'), self.data.url('content-script.js')],
    contentStyleFile: self.data.url('content-style.css'),
    onAttach: function (worker) {
        addWorker(worker);
        sendActiveState(ss.storage.isPluginActive);
    }
});

// move between tabs
tabs.on('activate', function () {
    sendActiveState();
});

// this actually fires before the worker's pageshow event so isn't useful as the workers array will be out of sync
//tabs.on('pageshow', function () {
//    sendActiveState();
//});

function addWorker (worker) {
    if(workers.indexOf(worker) > -1) {
        return;
    }

    worker.on('detach', handleWorkerDetach);
    worker.on('pageshow', handleWorkerShown);
    worker.on('pagehide', handleWorkerHidden);
    workers.push(worker);
}

function handleWorkerDetach () {
    removeWorker(this, true);
}

function handleWorkerShown () {
    addWorker(this);

    // back / forward page history
    // trying to send the state here will trigger the page hidden error
    sendActiveState();
}

function handleWorkerHidden () {
    removeWorker(this);
}

function removeWorker (worker, removeEvents) {
    var index = workers.indexOf(worker);

    removeEvents = removeEvents || false;

    if(index > -1) {
        if(removeEvents) {
            worker.removeListener('detach', handleWorkerDetach);
            worker.removeListener('pageshow', handleWorkerShown);
            worker.removeListener('pagehide', handleWorkerHidden);
        }

        workers.splice(index, 1);
    }
}

function getWorkersForCurrentTab () {
    var i;
    var tabWorkers = [];

    i = workers.length;

    while(--i > -1) {
        if(workers[i].tab.id === tabs.activeTab.id) {
            tabWorkers.push(workers[i]);
        }
    }

    return tabWorkers;
}

function handlePanelReady () {
    setActive(ss.storage.isPluginActive);
}

function setActive (bool) {
    ss.storage.isPluginActive = bool;
    panel.port.emit('active-changed', bool);
    sendActiveState();
}

function sendActiveState () {
    var tabWorkers = getWorkersForCurrentTab();
    var i = tabWorkers.length;

    while(--i > -1) {
        tabWorkers[i].port.emit('toggle-plugin', ss.storage.isPluginActive);
    }
}

function handleButtonChange (state) {
    if(state.checked) {
        panel.show({
            position: button
        });
    }
}

function handlePanelHide () {
    button.state('window', {checked: false});
}

function handleLinkClicked (url) {
    if(panel.isShowing) {
        panel.hide();
    }

    tabs.open(url);
}

function handlePluginToggled (bool) {
    if(panel.isShowing) {
        panel.hide();
    }

    setActive(bool);
}

最佳答案

尝试在page-mod中使用contentScriptWhen: "start"