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    <p>All info necessary to save/restore user efforts is in your states[] array which contains javascript objects defining the status of all your drag-drop items.</p> <p>Actually...</p> <p>...There's a LOT of info about serializing, transporting, saving, retrieving and deserializing javascript objects ;)</p> <p>For serializing javascript objects, use <code>JSON.stringify</code> which can serialize your array of objects into a single JSON string (JSON stands for JavaScriptObjectNotation). This single string is easily transported to your server for posting to your database.</p> <p>To get your state information back, you can ask the server to give you that same JSON string back. You can turn that JSON string back into an array of objects using <code>JSON.parse</code>.</p> <p>To transport and receive your JSON data string, you can use jQueries <code>$.ajax</code> method. Ajax can be used to send info to your server--this is called an ajax POST. Ajax can be used to request info from your server--this is called an ajax GET.</p> <p>When your server gets a POST request, it will take the JSON string you supply and save it in a database.</p> <p>When your server gets a GET request, it will query the database to retrieve the saved JSON string and send it back to your user.</p> <p>Setting up a server and a database is beyond the scope of a stackoverflow question, but here is a nice series of tutorials on how jQuery, JSON, Ajax, Php and MySQL-database can be used together to save and restore state:</p> <p>www.youtube.com/watch?v=Yz0RF__mFDU</p> <p>Here is a quick example of client-side code to serialize and POST your state information:</p> <pre><code>// Serialize the states array var JsonStringForTransport = JSON.stringify({stateForUserNumber7: states}); // POST the JSON to your server var thePost = $.ajax({ url: 'saveToServer.php', type: 'POST', dataType: 'json', data: JsonStringForTransport, contentType: 'application/json; charset=utf-8' }); thePost.always(function(result){ // use this during testing to be sure something's happening }); thePost.fail(function(result){ // handle failure }); thePost.done(function(result){ // handle success }); </code></pre> <p>Good luck in your project! :)</p>
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    1. POHTML5 Canvas - Saving and Restoring drag and drop canvas states
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    1. COExcellent - I shall have a very good look at this and those videos. And yes, now I know what to Google for, there is a fair amount of information out there to find :), thanks a lot.
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    2. COComing back to this... I have added the Ajax POST code to the Save button and when I press it in Firebug I can see the POST request occurring in the Console. I am going to be using Perl's Catalyst MVC Framework and Postgresql for the database. The url I have used in the POST is `homescreen`. So am I correct in thinking, I now need to find how to to get the JSON string that was supplied to the the `homescreen` page (in Perl) and then save the JSON string to Postgres? - thanks a lot
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    3. COI don't use Catalyst, but yes...You supply the JSON stringified JS object to your POST controller. Then you do an INSERT to save the JSON string to the postgresssql database.
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