Chrome API responseHeaders - google-chrome

Question

Based on this documentation: https://developer.chrome.com/extensions/webRequest.html#event-onHeadersReceived
I tried to display the response via the console like:
console.log(info.responseHeaders);
But its returning undefined.
But this works though:
console.log("Type: " + info.type);
Please help, I really need to get the responseHeaders data.

Answer 1

You have to request the response headers like this:
chrome.webRequest.onHeadersReceived.addListener(function(details){
console.log(details.responseHeaders);
},
{urls: ["http://*/*"]},["responseHeaders"]);
An example of use. This is one instance of how I use the webRequest api in my extension. (Only showing partial incomplete code)
I need to indirectly access some server data and I do that by making use of a 302 redirect page. I send a Head request to the desired url like this:
$.ajax({
url: url,
type: "HEAD"
success: function(data,status,jqXHR){
//If this was not a HEAD request, `data` would contain the response
//But in my case all I need are the headers so `data` is empty
comparePosts(jqXHR.getResponseHeader('redirUrl')); //where I handle the data
}
});
And then I silently kill the redirect while scraping the location header for my own uses using the webRequest api:
chrome.webRequest.onHeadersReceived.addListener(function(details){
if(details.method == "HEAD"){
var redirUrl;
details.responseHeaders.forEach(function(v,i,a){
if(v.name == "Location"){
redirUrl = v.value;
details.responseHeaders.splice(i,1);
}
});
details.responseHeaders.push({name:"redirUrl",value:redirUrl});
return {responseHeaders:details.responseHeaders}; //I kill the redirect
}
},
{urls: ["http://*/*"]},["responseHeaders","blocking"]);
I actually handle the data inside the onHeadersReceived listener, but this way shows where the response data would be.