This is how I use it across domains… Use an iframe from your parent domain – say parent.com Then on each child.com domain, just do a postMessage to your parent.com iframe All you need to do is setup a protocol of how to interpret your postMessage messages to talk to the parent.com iframe. I hope … Read more
Yes, use the File API, then you can process the images with the canvas element. This Mozilla Hacks blog post walks you through most of the process. For reference here’s the assembled source code from the blog post: // from an input element var filesToUpload = input.files; var file = filesToUpload[0]; var img = document.createElement(“img”); … Read more
I would suggest to store timestamp in the object you store in the localStorage var object = {value: “value”, timestamp: new Date().getTime()} localStorage.setItem(“key”, JSON.stringify(object)); You can parse the object, get the timestamp and compare with the current Date, and if necessary, update the value of the object. var object = JSON.parse(localStorage.getItem(“key”)), dateString = object.timestamp, now … Read more
To whoever also needs this problem solved: Firstly, I grab my image with getElementByID, and save the image as a Base64. Then I save the Base64 string as my localStorage value. bannerImage = document.getElementById(‘bannerImg’); imgData = getBase64Image(bannerImage); localStorage.setItem(“imgData”, imgData); Here is the function that converts the image to a Base64 string: function getBase64Image(img) { var … Read more
localStorage and sessionStorage both extend Storage. There is no difference between them except for the intended “non-persistence” of sessionStorage. That is, the data stored in localStorage persists until explicitly deleted. Changes made are saved and available for all current and future visits to the site. For sessionStorage, changes are only available per tab. Changes made … Read more
This is an extremely broad scope question, and a lot of the pros/cons will be contextual to the situation. In all cases, these storage mechanisms will be specific to an individual browser on an individual computer/device. Any requirement to store data on an ongoing basis across sessions will need to involve your application server side … Read more
localStorage only supports strings. Use JSON.stringify() and JSON.parse(). var names = []; names[0] = prompt(“New member name?”); localStorage.setItem(“names”, JSON.stringify(names)); //… var storedNames = JSON.parse(localStorage.getItem(“names”)); You can also use direct access to set/get item: localstorage.names = JSON.stringify(names); var storedNames = JSON.parse(localStorage.names);
Cookies and local storage serve different purposes. Cookies are primarily for reading server-side, local storage can only be read by the client-side. So the question is, in your app, who needs this data — the client or the server? If it’s your client (your JavaScript), then by all means switch. You’re wasting bandwidth by sending … Read more
Quoting from the Wikipedia article on Web Storage: Web storage can be viewed simplistically as an improvement on cookies, providing much greater storage capacity (10 MB per origin in Google Chrome(https://plus.google.com/u/0/+FrancoisBeaufort/posts/S5Q9HqDB8bh), Mozilla Firefox, and Opera; 10 MB per storage area in Internet Explorer) and better programmatic interfaces. And also quoting from a John Resig article … Read more
Looking at the Apple, Mozilla and Mozilla again documentation, the functionality seems to be limited to handle only string key/value pairs. A workaround can be to stringify your object before storing it, and later parse it when you retrieve it: var testObject = { ‘one’: 1, ‘two’: 2, ‘three’: 3 }; // Put the object … Read more