I've looked at this file for an hour and have tried a ton of permutations.
$(document).ready(function() {
var unreadMessages = document.getElementsByClassName("unreadMessage");
var previousEntries;
chrome.storage.sync.get(null, {
var previousEntries;
previousEntries = (data["item"]);
});
console.log(previousEntries);
});
Why does previousEntries throw an "Uncaught SyntaxError: unexpected identifier"?
This seems to be the most straightforward task. Is it a } () or , issue?
$(document).ready(function() {
var unreadMessages = document.getElementsByClassName("unreadMessage");
var previousEntries;
// vvvvvvvvvvvvvv
chrome.storage.sync.get(null, function(data){
// var previousEntries; And if you want to access this variable outside,
previousEntries = data["item"]; // don't redefine it here (no "var" keyword).
logValue(); // Now that the variable is set, you can use it
});
// console.log(previousEntries); // Undefined, because it is not set yet.
function logValue(){
console.log(previousEntries); // Now it should work (called from get's callback).
}
});
The reason the variable is not set yet is that chrome.storage.sync.get is, just like Ajax or a setTimeout, asynchronous. Imagine doing this:
var myVar;
setTimeout(function(){
myVar = 'Hello world!';
console.log(myVar); // logs "Hello world!" to the console
}, 100);
alert(myVar); // alerts undefined
chrome.storage.sync.get is asynchronous, meaning that any code below it will be executed before it gets the value. That's why they allow you to have a callback function, that is executed when you get the value. From there, you can execute the rest of your code (console.log() or other stuff that need that variable). Think of it like a setTimeout: jsfiddle.net/fdxgnyyj
dataindata["item"]coming from?