在使用chrome.tabs.onUpdated.addListener后访问给定的URL时删除侦听器 [英] Remove listener when given URL is visited after using chrome.tabs.onUpdated.addListener
问题描述
这是我的问题:我正在开发Gmail的Chrome扩展程序,并且需要在更新扩展程序时应用一些更改。
例如,我想要请确保扩展程序更新后,扩展程序将在Gmail中显示警告对话框。这意味着在更新时检查Gmail是否已在Chrome窗口中打开,如果不想创建侦听器以等待将来加载Gmail,然后显示警报对话框。下面的代码就是这样。但是,当发现新的Gmail选项卡时,我无法设法删除侦听器( chrome.tabs.onUpdated.removeListener ?)。
background.js
$ b
// [...]
//重新加载选项卡,其中Gmail已激活
函数reloadTab(order){
chrome.windows.getCurrent(function(win){
var cwin = win.id;
chrome.tabs.query({windowId:cwin},function(tabs){
var countGmailTabs = 0;
for(var i = 0; i< tabs.length; i ++){$ (t.match('mail.google.com')){
countGmailTabs + = 1;
if(order =
);
var t = tabs [i] .url; =='set'){
chrome.tabs.reload(tabs [i] .id);
} else if(order!=='set'){
var GmailTab =标签[i];
NewGmailURL(订单,GmailTab);
return;
}
}
}
//找不到Gmail!
if(countGmailTabs< 1&& order!=='set'){
chrome.tabs.onUpdated.addListener(function(tabId,changeInfo,tab){
if( tab.url.match('mail.google.com')&&; changeInfo.status ==='loading'){
NewGmailURL('update',tab);
return;
//一切正常,现在移除监听器。如何?
}
});
}
});
});
}
// [...]
感谢您的帮助!
有关详情,请使用URL参数显示警告对话框。
$ b
//修改Gmail URL
var updated = false;
功能NewGmailURL(PARAM,ZTAB){
如果(PARAM === '更新'){
urlMyExtension = ztab.url.replace(urlGmail + '查询=更新&安培;?',urlGmail +'?query ='+ param +'&');
} else {
urlMyExtension = ztab.url.replace(urlGmail,urlGmail +'?query ='+ param +'&');
}
if(!done&& param!=='updated'){
chrome.tabs.update(ztab.id,{
url:urlMyExtension,
突出显示:ztab.highlighted
},null);
updated = true;
[已更新]回答
如果有人遇到同样的问题,这里是@ExpertSystem的答案:
//收听标签URL
函数myListener(tabId,info,tab){
if(tab.url.match(mail.google。 com)&&(info.status ===loading)){
NewGmailURL(update,tab);
/ *现在,让我们解除我们的监听器职责* /
chrome.tabs.onUpdated.removeListener(myListener);
return;
//重新加载选项卡,其中的Gmail处于活动状态
函数reloadTab(order){
chrome.tabs.query({currentWindow:true },function(tabs){
var countGmailTabs = 0;
for(var i = 0; i< tabs.length; i ++){
var t = tabs [i] .url ;
if(t.match('mail.google.com')){
countGmailTabs + = 1;
if(order ==='set'){
chrome .tabs.reload(tabs [i] .id);
} else if(order!=='set'){
var GmailTab = tabs [i];
NewGmailURL(order, GmailTab);
return;
}
}
}
//找不到Gmail!
if(countGmailTabs< 1&& order! =='set'){
chrome.tabs.onUpdated.addListener(GmailListener);
}
});
}
为了能够删除侦听器不要将其实现为匿名函数。将它实现为named函数,允许您在调用 removeListener()
时引用它的改变。
例如:
/ *更改:* /
chrome.tabs.onUpdated.addListener(function(tabId,changeInfo,tab){...});
$ b $ * * /
函数myListener(tabId,info,tab){
if(tab.url.match(mail.google.com)& ;&(info.status ===loading)){
NewGmailURL(update,tab);
/ *现在,让我们解除我们的监听器职责* /
chrome.tabs.onUpdated.removeListener(myListener);
return;
}
});
chrome.tabs.onUpdated.addListener(myListener);
顺便说一句,(与您的问题无关,但)您正在进行一些超快的调用:
您不需要获取当前窗口,然后获取其标签,就像这样:
chrome.windows.getCurrent(function(win){
var cwin = win.id;
chrome.tabs.query({windowId:cwin},函数(标签){
...
您可以在一次调用中执行此操作,如下所示:
(另请参阅 chrome.windows.getCurrent() )
chrome.window.getCurrent({populate:true},function(win){
var tabs = win.tabs;
...
甚至像这样:
(另请参见 chrome.tabs.query() )
chrome.tabs.query({currentWindow:true},function(tabs){
...
Here is my problem: I'm developing a Chrome extension for Gmail and needs to apply some changes when the extension is updated.
For example, I want to be sure that the extension will display an alert dialog within Gmail after the extension has been updated. This implies to check whether Gmail is already open in a Chrome window at the time of the update, and if not to create a listener in order to wait for Gmail to be loaded in the future and then to display the alert dialog.
The code below does just that. However, I cannot manage to remove the listener (chrome.tabs.onUpdated.removeListener?) when a new Gmail tab has been discovered.
background.js
// [...] code before
// Reload Tabs where Gmail is active
function reloadTab(order) {
chrome.windows.getCurrent(function(win) {
var cwin = win.id;
chrome.tabs.query({windowId: cwin}, function(tabs) {
var countGmailTabs = 0;
for (var i = 0; i < tabs.length; i++) {
var t = tabs[i].url;
if (t.match('mail.google.com')) {
countGmailTabs += 1;
if (order === 'set') {
chrome.tabs.reload(tabs[i].id);
} else if (order !== 'set') {
var GmailTab = tabs[i];
NewGmailURL(order, GmailTab);
return;
}
}
}
// Gmail not found !
if (countGmailTabs < 1 && order !== 'set') {
chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab) {
if ( tab.url.match('mail.google.com') && changeInfo.status === 'loading' ) {
NewGmailURL('update', tab);
return;
// Everything OK, now remove listener. How?
}
});
}
});
});
}
// [...]
Thanks for your help!
For information, the alert dialog is displayed thanks to URL parameters.
// Modify Gmail URL
var updated = false;
function NewGmailURL(param, ztab) {
if (param === 'updated') {
urlMyExtension = ztab.url.replace(urlGmail + '?query=update&', urlGmail +'?query=' + param + '&');
} else {
urlMyExtension = ztab.url.replace(urlGmail, urlGmail + '?query=' + param + '&');
}
if (!done && param !== 'updated') {
chrome.tabs.update(ztab.id, {
url: urlMyExtension,
highlighted: ztab.highlighted
}, null);
updated = true;
}
}
[UPDATED] ANSWER
In case anyone meets the same problem, here is the answer thanks to @ExpertSystem:
// Listen to Tabs URL
function myListener(tabId, info, tab) {
if (tab.url.match("mail.google.com") && (info.status === "loading")) {
NewGmailURL("update", tab);
/* Now, let's relieve ourselves from our listener duties */
chrome.tabs.onUpdated.removeListener(myListener);
return;
}
}
// Reload Tabs where Gmail is active
function reloadTab(order) {
chrome.tabs.query({ currentWindow: true }, function(tabs) {
var countGmailTabs = 0;
for (var i = 0; i < tabs.length; i++) {
var t = tabs[i].url;
if (t.match('mail.google.com')) {
countGmailTabs += 1;
if (order === 'set') {
chrome.tabs.reload(tabs[i].id);
} else if (order !== 'set') {
var GmailTab = tabs[i];
NewGmailURL(order, GmailTab);
return;
}
}
}
// Gmail not found !
if (countGmailTabs < 1 && order !== 'set') {
chrome.tabs.onUpdated.addListener(GmailListener);
}
});
}
In order to be able to remove a listener do not implement it as an anonymous function. Implementing it as "named" function, allows you to reference it alter when calling removeListener()
.
E.g.:
/* Change this: */
chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab) {...});
/* To this: */
function myListener(tabId, info, tab) {
if (tab.url.match("mail.google.com") && (info.status === "loading")) {
NewGmailURL("update", tab);
/* Now, let's relieve ourselves from our listener duties */
chrome.tabs.onUpdated.removeListener(myListener);
return;
}
});
chrome.tabs.onUpdated.addListener(myListener);
BTW, (not related to your problem, but) you are making a couple of superflous calls:
You don't need to get the current window and then get its tabs, like this:
chrome.windows.getCurrent(function(win) {
var cwin = win.id;
chrome.tabs.query({windowId: cwin}, function(tabs) {
...
You can do it in one call, like this:
(See, also, chrome.windows.getCurrent())
chrome.window.getCurrent({ populate: true }, function(win) {
var tabs = win.tabs;
...
Or even like this:
(See, also, chrome.tabs.query())
chrome.tabs.query({ currentWindow: true }, function(tabs) {
...
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