Why does chrome.extension.getBackgroundPage() return null?
I have a manifest.json file that looks like this:
{
"name": "Zend Debugger Extension",
"version": "0.1",
"background_page": "background.html",
"permissions": [
"cookies", "tabs", "http://*/*", "https://*/*"
],
"browser_action": {
"default_title": "Launch Zend Debugger",
"default_icon": "icon.png",
"popup": "popup.html"
}
}
Here's my background.html :
<html>
<script>
function testRequest() {
console.log("test Request received");
}
</script>
</html>
And my popup.html :
<script>
function debug(target) {
if (target.id == 'thisPage') {
console.log('sending request');
chrome.extension.getBackgroundPage().testRequest();
}
}
</script>
<div onclick="debug(this)" id="thisPage">Current Page</div>
However, the background.html page doesn't seem to be accessible. I'm getting this error:
Uncaught TypeError: Cannot call method 'testRequest' of null
When I inspect chrome.extension.getBackgroundPage() I get a null value. I'm thinking I have made a mistake in my manifest file, but I can't see what I've done wrong.
Thanks.
You are missing the background permission, take a look at my manifest.json file of my chrome extension:
{
"content_scripts": [
{
"matches": ["http://*/*"],
"js": ["jquery.js", "asserts.js"]
}
],
"name": "Test Extension",
"version": "1.0",
"description": "A test extension to inject js to a webpage.",
"background_page": "background.html",
"options_page": "options.html",
"browser_action": {
"default_icon": "icon.png",
"popup": "popup.html"
},
"permissions": [
"tabs",
"http://*/*", "https://*/*", "<all_url>", "background"
]
}
EDIT: Are you sure you have the background.html file on the same folder as all your chrome-extension's files?, and if so, try reloading your extension from the extension management page, I remember once had a bug that my extension didn't reload, so I went to the developer's tools for my background page and executed window.location.reload(true); from console, that fixed it. Please respond if this worked, I will keep researching
Here's another answer with more options:
chrome.extension.getBackgroundPage() returns null after awhile
According to the referenced page (Difference between Event and Background Page) there is a better option to get the background while still using Event Page :
If your extension uses, extension.getBackgroundPage, switch to runtime.getBackgroundPage instead. The newer method is asynchronous so that it can start the event page if necessary before returning it.
链接地址: http://www.djcxy.com/p/55830.html上一篇: 通过编程切换Android配置文件