我在尝试编写一个简单的Chrome扩展插件,它使用declarativeWebRequest(目前处于测试阶段;我使用25.0.1364.0)替换了http响应中的Content-Type
标头。如何使用Chrome的声明式WebRequest来更改http响应标头
的代码是基于Catifier例如,如果我改变了registerRules
方法:
var RequestMatcher = chrome.declarativeWebRequest.RequestMatcher;
var RemoveResponseHeader = chrome.declarativeWebRequest.RemoveResponseHeader;
var AddResponseHeader = chrome.declarativeWebRequest.AddResponseHeader;
function registerRules() {
var changeRule = {
priority: 100,
conditions: [
// If any of these conditions is fulfilled, the actions are executed.
new RequestMatcher({
contentType: ['audio/mpeg']
}),
],
actions: [
new RemoveResponseHeader({name: 'Content-Type'}),
new AddResponseHeader({name: 'Content-Type', value: 'application/octet-stream'}),
new AddResponseHeader({name: 'X-ChromeExt-Content-Type', value: 'trap'})
]
};
var callback = function() {
if (chrome.extension.lastError) {
console.error('Error adding rules: ' + chrome.extension.lastError);
} else {
console.info('Rules successfully installed');
chrome.declarativeWebRequest.onRequest.getRules(null,
function(rules) {
console.info('Now the following rules are registered: ' +
JSON.stringify(rules, null, 2));
});
}
};
chrome.declarativeWebRequest.onRequest.addRules(
[changeRule], callback);
}
它工作正常在这个意义上,这些规则是注册用户,我从浏览器控制台下面的反馈:
Now the following rules are registered: [
{
"actions": [
{
"instanceType": "declarativeWebRequest.RemoveResponseHeader",
"name": "Content-Type"
},
{
"instanceType": "declarativeWebRequest.AddResponseHeader",
"name": "Content-Type",
"value": "application/octet-stream"
},
{
"instanceType": "declarativeWebRequest.AddResponseHeader",
"name": "X-ChromeExt-Content-Type",
"value": "trap"
}
],
"conditions": [
{
"contentType": [
"audio/mpeg"
],
"instanceType": "declarativeWebRequest.RequestMatcher"
}
],
"id": "_0_",
"priority": 100
}
]
问题是,代码实际上并没有产生任何效果,也就是说http响应头保持不变。我不确定这是否与(不是固定的)bug in Chrome没有显示更改的标题相关。但无论如何,我有以下问题:
1)适用于contentType
上述RequestMatcher
正确或我应该使用responseHeaders
而不是匹配(以某种方式指出Content-Type
)?
2)如果RequestMatcher
应该适用于responseHeaders
,那么这样的规则的语法是什么?
new RequestMatcher({
responseHeaders: // what to place here to match a value in a specific header line?
// or possibly responseHeaders['Content-Type']: ...?
})
3)如何调试规则执行?我的意思是我想跟踪和分析条件如何处理和执行的动作。没有这个使用declarativeWebRequest
将是一个难题,恕我直言。
在此先感谢。