使用可选权限的方法可以在不禁用现有用户的扩展的情况下添加新的扩展权限,同时确保新用户在安装后被提示接受所需和可选权限。
chrome.permissions.request API 可以请求可选权限,但前提是要有用户操作。满足此要求并仍然提供无缝用户体验的最简单方法是在后台页面中检查权限,并在运行时在弹出窗口中请求可选权限。
权限请求可以在加载扩展之后的后台页面中进行(安装和随后的浏览器启动后)。任何缺少任何权限的现有用户将在重新启动浏览器后被提示接受权限。
以下示例包括:
- 背景页 JavaScript(background_page.js)
- 通知弹出窗口 HTML 文件(notification_popup.html)
- 通知弹出窗口 JavaScript(notification_popup.js)
您还需要在 manifest.json 中声明 "optional_permissions" 才能使示例正常工作。该示例适用于 Chrome Extension 和 Firefox Add-on。
background_page.js
var brwsr = null;
if (typeof chrome != "undefined") {
brwsr = chrome;
}
else{
brwsr = browser;
}
var opt_perms = brwsr.runtime.getManifest().optional_permissions;
var requiredOptionalPermissions = {}
if(typeof opt_perms!="undefined" && opt_perms.length>0){
var perms = []
var origins = []
var re = new RegExp("^(http|https)://", "i");
for(var i=0; i<opt_perms.length; i++){
if(opt_perms[i]==="<all_urls>"|| re.test(opt_perms[i])){
origins.push(opt_perms[i])
}
else{
perms.push(opt_perms[i])
}
}
if(perms.length>0){
requiredOptionalPermissions.permissions = perms
}
if(origins.length>0){
requiredOptionalPermissions.origins = origins
}
}
var requiresPermission = ()=>{
}
var runFunctionsRequiringOptPermissions = function(requiredPermissions={}, userGesture=false, callback=()=>{}){
if(typeof requiredPermissions.permissions!="undefined" || typeof requiredPermissions.origins!="undefined"){
brwsr.permissions.contains(requiredPermissions, function(res) {
if (!res) {
if(userGesture){
brwsr.permissions.request(requiredPermissions, function(granted){
if(granted){
requiresPermission()
}
callback();
});
return;
}
window.open("notification_popup.html", "extension_popup", "width=530,height=190,status=no,scrollbars=yes,resizable=no,screenY=+"+(screen.height/2-95)+",screenX="+(screen.width/2-265));
}
else{
requiresPermission()
}
});
}
}
runFunctionsRequiringOptPermissions(requiredOptionalPermissions)
brwsr.runtime.onConnect.addListener(function(port) {
if(port.name == "optionalPermRequestPopup"){
port.onMessage.addListener(
function(request, sender, sendResponse) {
if (request.okButtonClicked === true) {
runFunctionsRequiringOptPermissions(requiredOptionalPermissions, true, function(){
port.postMessage({'close':true});
})
return;
}
port.postMessage({'close':true})
}
);
}
});
notification_popup.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Extension Name</title>
<style>
.container {
font-size:medium;
text-align:center;
}
.button{
height: 30px;
width: 70px;
background-color: #448be9;
color: white;
border-color: #448be9;
border-width: thin;
margin-right: 10px;
float: right;
}
.btnCancel{
background-color: white;
color: #448be9
}
</style>
</head>
<body>
<div class="container">
<p class='text'>Please upgrade the permissions to enable the latest features.</p>
<button class="button btnCancel">Cancel</button>
<button class="button btnOk">OK</button>
</div>
<script src="notification_popup.js"></script>
</body>
</html>
notification_popup.js
var brwsr = null;
if (typeof chrome != "undefined") {
brwsr = chrome;
}
else{
brwsr = browser;
}
var port = brwsr.runtime.connect({
name : "optionalPermRequestPopup"
});
window.addEventListener("load", function(event) {
var okButtons = document.querySelectorAll(".btnOk");
okButtons.forEach(function(okButton) {
okButton.addEventListener("click", function(event) {
port.postMessage({okButtonClicked: true})
});
});
port.onMessage.addListener(function(request) {
for (var key in request) {
switch(key){
case "close":
window.close();
break;
default:
break;
}
}
});
});