Question

I am having trouble with two functions because they rely on chaining Async Tasks. The clearAll is a click event which should empty the database then reload the page. Clear is a function from the database module (database.clear).

I would like to use JQuery Promises/Deffered if they are appropriate but I cant quite grasp them for this use case.

I have re-written the code following @Larry K’s answer

    clearAll: function()
    {
        var refresh = function()
        {
            localStorage.clear();  
            sessionStorage.clear();
            window.location.href = window.location.pathname;
            console.log("feeling refreshed");
        };

        database.open();

                    //This is what I'd like to be able to do
                    //With Jquery or callbacks
        $.when(database.clear()).then(refresh);

    },

clear: function (callback, errorCallback)
{
    var sql = "SELECT name FROM sqlite_master WHERE type='table' AND name != ?",
    args = ["__WebKitDatabaseInfoTable__"];

    var dbTableNamesResult = function (tx, result)
    {
       var dropSql  = "";

       for (var i = 0; i < result.rows.length; i++)
       {
        dropSql = "DROP TABLE IF EXISTS " + result.rows.item(i).name + "; ";
        execute(dropSql);
       }
    };

    execute(sql, args, dbTableNamesResult);
},

Answer 1

Having attempted to implement jQuery deferred myself the answer I was looking for was provided by zerkms’s answer to How can I write this as a jQuery deffered function