sending response in message passing on history search - google-chrome-extension

Question

I have been trying to send search history in the background page and send response back to front page. I am using message parsing .
I am unable to send response back after searching history.
--------background.js-------------
var SECONDS_PER_WEEK = 1000 * 60 * 60 * 24 * 7;
chrome.extension.onMessage.addListener(
function(request, sender, sendResponse) {
if(request === "getHistory"){
var value = getHistory();
console.log("Response" , value);
sendResponse(value);
}
}
);
function getHistory(){
var current_time = new Date().getTime();
var timeToFetch = current_time - SECONDS_PER_WEEK;
return chrome.history.search({
'text' : '',
'startTime' : timeToFetch
},
function(resp){
return resp;
});
}
The problem lies here itself as on logging I get 'undefined' as response.
Can anyone direct me to the solution

Answer 1

Most of the Chrome.* API functions are asynchronous so try doing it something like this:
background.js
var SECONDS_PER_WEEK = 1000 * 60 * 60 * 24 * 7;
chrome.extension.onMessage.addListener(function(request, sender, sendResponse) {
if(request === "getHistory"){
getHistory(sendResponse);
return true;
}
});
function getHistory(sendResponse){
var current_time = new Date().getTime();
var timeToFetch = current_time - SECONDS_PER_WEEK;
chrome.history.search({
'text' : '',
'startTime' : timeToFetch
},
function(resp){
console.log("Response: " + resp);
sendResponse(resp);
});
}