我正在尝试创建我的第一个Google Chrome扩展程序。
为什么这不是从example.com网站复制粘贴到我的弹出窗口的任何想法?
popup.js:
document.addEventListener('DOMContentLoaded', function () {
var xhr = new XMLHttpRequest();
xhr.open("GET", chrome.extension.getURL('http://example.com'), false);
xhr.send();
document.getElementById('response').innerHTML = xhr.responseText;
});
popup.html:
<!doctype html>
<html>
<head>
<script type="text/javascript" src="popup.js"></script>
</head>
<body>
<p id="response"></p>
</body>
</html>
的manifest.json:
{
"manifest_version": 2,
"name": "Getting started",
"description": "Display test from Example.com",
"version": "1.0",
"browser_action": {
"default_icon": "icon.png",
"default_popup": "popup.html",
},
"permissions": [
"http://example.com"
]
}
顺便说一句,我并不打算将捕获的内容直接注入弹出窗口! (脚本注入等)在这个阶段,我只是弄清楚一切是如何运作的。
答案 0 :(得分:1)
有几个问题
您需要为您所做的任何XMLHttp请求请求权限,以便在您的扩展程序中明确标记。这样做的方法是在manifest.son中列出您要访问的网站。这非常简单,并在此处介绍:https://developer.chrome.com/extensions/xhr
请求本身,当您发送请求时,它没有立即回答。这是因为它正在通过互联网并在后台提出您的请求。所以你在调用send之后不能直接询问responseText - 因为它还不知道答案。你必须告诉它在完成加载后给你回电话。这称为回调。
调试。您可以从Google安装一个工具,使“Inspect Element”适用于您的扩展程序。这意味着您可以右键单击下拉列表,然后从上下文菜单中选择inspect元素。然后,您可以转到控制台选项卡,查看所有javascript错误。 https://chrome.google.com/webstore/detail/chrome-apps-extensions-de/ohmmkhmmmpcnpikjeljgnaoabkaalbgc?hl=en
这也意味着你可以在任何地方撒上console.log(“在这里”),你可以看到被调用的内容和什么不是......
这就是我将你的工作与谷歌样本结合起来的工作。
希望这有帮助! JFO
的manifest.json
{
"manifest_version": 2,
"name": "Getting started example",
"description": "This extension shows a Google Image search result for the current page",
"version": "1.0",
"browser_action": {
"default_icon": "icon.png",
"default_popup": "popup.html"
},
"permissions": [
"activeTab",
"http://www.example.com/"
]
}
Popup.js
// makeWebRequest
//
// ANY URLs you want to call with "makeWebRequest" need to be listed in your manifest.json
// https://developer.chrome.com/extensions/xhr
//
// responseType 'json' 'document' 'text'
// callback is the function to call back on success. will be passed the XMLHttpRequest
// errorCallback is called when there's a problem
function makeWebRequest(urlToLoad, responseType, callback, errorCallback) {
console.log("making web request for: " + urlToLoad);
var xmlReq = new XMLHttpRequest();
xmlReq.open('GET', urlToLoad);
// The Google image search API responds with JSON, so let Chrome parse it.
xmlReq.responseType = responseType;
xmlReq.onload = function() {
// Parse and process the response from Google Image Search.
var response = xmlReq.response;
/// if (!response || !response.responseData || !response.responseData.results ||
// response.responseData.results.length === 0) {
if (!xmlReq.response) {
errorCallback('No response from the web request!');
return;
}
callback(xmlReq);
};
xmlReq.onerror = function() {
errorCallback('Network error.');
};
xmlReq.send(); // this goes away, makes the internet request, then calls back when it's finished.
}
// This is called when the extension loads.
document.addEventListener('DOMContentLoaded', function () {
// Response type:
// use json for json, document for html documents, text for raw text
makeWebRequest("http://www.example.com/index.html", "document",
function (xmlReq) {
// this is the function that is called back on when "Send" finishes
// returns an HTMLDocument because we passed the "document"
// responseType into makeWebRequest.
var doc = xmlReq.response;
console.log("web request finished " + xmlReq.response);
document.getElementById('response').innerHTML = doc.documentElement.innerHTML;
}
, function(errorMessage) {
// this is the function that is called back on when there is an error
// requesting the file
console.log("got error:" + errorMessage);
});
});
Popup.html
<!doctype html>
<!--
This page is shown when the extension button is clicked, because the
"browser_action" field in manifest.json contains the "default_popup" key with
value "popup.html".
-->
<html>
<head>
<title>Getting Started Extension's Popup</title>
<style>
body {
font-family: "Segoe UI", "Lucida Grande", Tahoma, sans-serif;
font-size: 100%;
}
#status {
/* avoid an excessively wide status text */
white-space: pre;
text-overflow: ellipsis;
overflow: hidden;
max-width: 400px;
}
</style>
<!--
- JavaScript and HTML must be in separate files: see our Content Security
- Policy documentation[1] for details and explanation.
-
- [1]: https://developer.chrome.com/extensions/contentSecurityPolicy
-->
<script src="popup.js"></script>
</head>
<body>
Sample extension
<div id="status"></div>
<p id="response"></p>
<img id="image-result" hidden>
</body>
</html>