I read some of the chrome docs and got this basic example working.
Now I want to make the request based on an event happening. The event is triggered and contentUpdateData() runs, but the chrome.runtime.sendMessage within the function doesn't seem to work. Any ideas why?
/* content.js */
var data = []
chrome.runtime.onMessage.addListener(
function(request, sesnder, sendResponse) {
if (request.message === 'popupClicked') {
contentUpdateData();
}
}
)
function contentUpdateData() {
console.log('Code works up to here. Button clicked in popup.html, recieved in content.js. Need to get info from background.js')
chrome.runtime.sendMessage({greeting: "hello"}, function(response) {
console.log(response.farewell);
data = response.data
});
}
/* background.js basic example from chrome */
chrome.runtime.onMessage.addListener(
function(request, sender, sendResponse) {
console.log(sender.tab ?
"from a content script:" + sender.tab.url :
"from the extension");
if (request.greeting === "hello")
sendResponse({farewell: "goodbye", data: null});
}
);
You need to return true from the event listener in backgroundjs. This saves sendResponse() from garbage collection.
chrome.runtime.onMessage.addListener(function (request, sender, sendResponse) {
if (request.greeting === "hello") sendResponse({ farewell: "goodbye", data: null });
// VERY IMPORTANT
return true;
});
Somehow the background.js did not sync properly after updating the extension. This was the cause for the error.