例如，我在 Firefox 中打开了以下页面：
<html>
<head></head>
<body> text
<iframe id="wikipedia" src="http://en.wikipedia.org"></iframe>
</body>
</html>
如何从我的插件中获取 iframe 中显示的维基百科文本？
即
...
Welcome to Wikipedia,
the free encyclopedia that anyone can edit.
4,462,480 articles in English
...
等等
【问题讨论】：
标签： javascript firefox iframe firefox-addon
此代码在最近的 navigator:browser 窗口中打开一个新选项卡，并在加载时查找 iframe 并获取其内容/
这个解决方案更好，因为如果 iframe 正在加载，我会测试它是否加载 iframe.contentDocument 是否存在，这不是最准确的测试方法，我现在想不出另一个. 如果其他人看到此内容，请分享一个更好的方法来查看 iframe 是否已加载
但如果 iframe 正在加载，它将等待 iframe 加载，而不是将 iframe 的 html 记录到浏览器控制台
将此复制粘贴到暂存器，确保环境设置为“浏览器”，这是经过测试和工作的
Components.utils.import('resource://gre/modules/Services.jsm')
var aDOMWindow = Services.wm.getMostRecentWindow('navigator:browser');
var newTabBrowser = aDOMWindow.gBrowser.getBrowserForTab(aDOMWindow.gBrowser.loadOneTab('http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_tolocaletimestring', {
inBackground: false
}));
newTabBrowser.addEventListener('load', function onloadFunc() {
Services.appShell.hiddenDOMWindow.console.log('tab loaded');
newTabBrowser.removeEventListener('load', arguments.callee, true);
var doc = newTabBrowser.contentDocument;
var win = doc.defaultView;
var iframes = doc.querySelectorAll('iframe');
Services.appShell.hiddenDOMWindow.console.log('number of iframes in this tab = ' + iframes.length);
[].forEach.call(iframes, function (frm, i) {
logIframeHtml(frm, i);
});
}, true);
function logIframeHtml(iframe, i) {
iframe.removeEventListener('DOMContentLoaded', logIframeHtml, true); //this line removes the event listneer if it had one
var iframeDoc = iframe.contentDocument;
if (!iframeDoc) {
Services.appShell.hiddenDOMWindow.console.log('iframe ' + i + ' is not fully loaded yet as it its contentDocument does not exist');
iframe.addEventListener('DOMContentLoaded', logIframeHtml, true);
} else {
var iframeInnerHtml = iframeDoc.documentElement.innerHTML;
Services.appShell.hiddenDOMWindow.console.log('iframe ' + i + ' innerHTML = ' + iframeInnerHtml);
}
}
【讨论】：
在最近的导航器中刚刚加载的选项卡的解决方案：浏览器和 iframe 已经加载
Components.utils.import('resource://gre/modules/Services.jsm')
var aDOMWindow = Services.wm.getMostRecentWindow('navigator:browser');
var iframes = aDOMWindow.gBrowser.contentDocument.querySelectorAll('iframe');
Services.appShell.hiddenDOMWindow.console.log('number of iframes in this tab = ' + iframes.length);
[].forEach.call(iframes, function (frm, i) {
var iframeInnerHtml = frm.contentDocument.documentElement.innerHTML;
});
function logIframeHtml(iframe, i) {
iframe.removeEventListener('DOMContentLoaded', logIframeHtml, true); //this line removes the event listneer if it had one
var iframeDoc = iframe.contentDocument;
if (!iframeDoc) {
Services.appShell.hiddenDOMWindow.console.log('iframe ' + i + ' is not fully loaded yet as it its contentDocument does not exist');
iframe.addEventListener('DOMContentLoaded', logIframeHtml, true);
} else {
var iframeInnerHtml = iframeDoc.documentElement.innerHTML;
Services.appShell.hiddenDOMWindow.console.log('iframe ' + i + ' innerHTML = ' + iframeInnerHtml);
}
}
此解决方案适用于当前选项卡，但不信任 iframe 是否已加载：
Components.utils.import('resource://gre/modules/Services.jsm')
var aDOMWindow = Services.wm.getMostRecentWindow('navigator:browser');
var iframes = aDOMWindow.gBrowser.contentDocument.querySelectorAll('iframe');
Services.appShell.hiddenDOMWindow.console.log('number of iframes in this tab = ' + iframes.length);
[].forEach.call(iframes, function (frm, i) {
logIframeHtml(frm, i);
});
function logIframeHtml(iframe, i) {
iframe.removeEventListener('DOMContentLoaded', logIframeHtml, true); //this line removes the event listneer if it had one
var iframeDoc = iframe.contentDocument;
if (!iframeDoc) {
Services.appShell.hiddenDOMWindow.console.log('iframe ' + i + ' is not fully loaded yet as it its contentDocument does not exist');
iframe.addEventListener('DOMContentLoaded', logIframeHtml, true);
} else {
var iframeInnerHtml = iframeDoc.documentElement.innerHTML;
Services.appShell.hiddenDOMWindow.console.log('iframe ' + i + ' innerHTML = ' + iframeInnerHtml);
}
}
【讨论】：