Chrome extension send response does not work

Question

I am writing a chrome extension, but the send response does not work.

chrome.runtime.onMessage.addListener(
    function(request, sender, sendResponse) {

            if(!request.method){

                    return false;

            }

            if(request.method=='postList' && request.post_list){
                // alert(1);                                                                                                                                                                            
                    a_facebook_api.getPostFromDB(request.post_list, function(data){
                            alert(data);                                                                                                                                                              
                            sendResponse(data);                                                                                                                                                       

                    });

            } else if(request.method=='postAdd' && request.post_data){

                    a_facebook_api.addPostToDB(request.post_data, function(data){

                            sendResponse(data);

                    });

    }

            return true;

}
);

 chrome.runtime.sendMessage({method: "postList",post_list: post_list}, function(response) {

         alert(response);

            });

Alert data works. This gives me data in JSON format. However, a warning (response) does not show any message. Can someone give me some ideas why this is not working?

Thank you in advance!

Answer 1

You did not indicate that this code is in the content of the script or background page. From looking at it, I assume this is part of the contents of the script.

, "[Object Object]", , , . "response.responseData", , "responseData" .

, , script, , .

. script:

//Document ready
window.onload = function() {
    alert('Ready');
    //Send a message
    sendMessage();
}

//Get message from background page
chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
    //Alert the message
    alert("The message from the background page: " + request.greeting);//You have to choose which part of the response you want to display ie. request.greeting
    //Construct & send a response
    sendResponse({
        response: "Message received"
    });
});

//Send message to background page
function sendMessage() {
    //Construct & send message
    chrome.runtime.sendMessage({
        method: "postList",
        post_list: "ThePostList"
    }, function(response) {
        //Alert the message
        alert("The response from the background page: " + response.response);//You have to choose which part of the response you want to display ie. response.response
    });
}

script:

//Get message from content script
chrome.runtime.onMessage.addListener(
    function(request, sender, sendResponse) {
        //Alert the message
        alert('The message from the content script: ' + request.method);//You have to choose which part of the response you want to display ie. request.method
        //Construct & send a response
        sendResponse({
            response: "Message received"
        });
    }
);

//Send message to content script
function sendDetails(sendData) {
    //Select tab
    chrome.tabs.query({active: true, currentWindow: true}, function(tabs) {
        //Construct & send message
        chrome.tabs.sendMessage(tabs[0].id, {
            greeting: sendData
        }, function(response) {
            //On response alert the response
            alert("The response from the content script: " + response.response);//You have to choose which part of the response you want to display ie. response.response
        });
    });
}

, script , sendResponse .

, .

Answer 2

Chrome: ​​.

return true .