Hello,
I'm working with the SchedulerDataSource within an Android Cordova project and I'm using the offline capabilities of the SchedulerDataSource keep the data in the LocalStorage when the device goes offline. As long as the App is running going on- and offline works as expected, but when I start the App offline (i.e. without network connection) the data within the LocalStorage gets corrupted and is pretty useless afterwards. As far as I could find out the issue is connected to the schema configuration of the datasource. When I use field mappings (the from option) in the model of the schema configuration all mapped field values are set to null upon an 'offline' startup.
The problem is not related to Android as I can also reproduce it in a Windows environment. In addition the standard DataSource component shows the same behaviour.
Here's a modified sample from the demos to illustrate the effect (see comment in code to simulate offline startup):
<!DOCTYPE html><html><head> <meta charset="utf-8"> <title>Kendo UI Snippet</title> <link rel="stylesheet" href="http://cdn.kendostatic.com/2015.1.408/styles/kendo.common.min.css"> <link rel="stylesheet" href="http://cdn.kendostatic.com/2015.1.408/styles/kendo.rtl.min.css"> <link rel="stylesheet" href="http://cdn.kendostatic.com/2015.1.408/styles/kendo.default.min.css"> <link rel="stylesheet" href="http://cdn.kendostatic.com/2015.1.408/styles/kendo.dataviz.min.css"> <link rel="stylesheet" href="http://cdn.kendostatic.com/2015.1.408/styles/kendo.dataviz.default.min.css"> <link rel="stylesheet" href="http://cdn.kendostatic.com/2015.1.408/styles/kendo.mobile.all.min.css"> <script src="http://code.jquery.com/jquery-1.9.1.min.js"></script> <script src="http://cdn.kendostatic.com/2015.1.408/js/kendo.all.min.js"></script></head><body> <div id="example"> <div id="team-schedule"> <label>Online: </label><input id="online" type="checkbox" checked> </div> <div id="scheduler"></div> </div> <script> $(function() { var ds = new kendo.data.SchedulerDataSource({ offlineStorage: "hs-scheduler-offlinetest", batch: true, transport: { read: { dataType: "jsonp" }, update: { dataType: "jsonp" }, create: { dataType: "jsonp" }, destroy: { dataType: "jsonp" }, parameterMap: function(options, operation) { if (operation !== "read" && options.models) { return {models: kendo.stringify(options.models)}; } } }, schema: { model: { id: "taskId", fields: { taskId: { from: "TaskID", type: "number" }, title: { from: "Title", defaultValue: "No title", validation: { required: true } }, start: { type: "date", from: "Start" }, end: { type: "date", from: "End" }, startTimezone: { from: "StartTimezone" }, endTimezone: { from: "EndTimezone" }, description: { from: "Description" }, recurrenceId: { from: "RecurrenceID" }, recurrenceRule: { from: "RecurrenceRule" }, recurrenceException: { from: "RecurrenceException" }, ownerId: { from: "OwnerID", defaultValue: 1 }, isAllDay: { type: "boolean", from: "IsAllDay" } } } }, filter: { logic: "or", filters: [ { field: "ownerId", operator: "eq", value: 1 }, { field: "ownerId", operator: "eq", value: 2 } ] } }); // -------------------------------------------------------------------------- // --- uncomment line below to simulate an offline start upon page reload --- //ds.online(false); $("#scheduler").kendoScheduler({ date: new Date("2013/6/13"), startTime: new Date("2013/6/13 07:00 AM"), height: 600, views: [ "day", { type: "workWeek", selected: true }, "week", "month", "agenda" ], timezone: "Etc/UTC", dataSource: ds, resources: [ { field: "ownerId", title: "Owner", dataSource: [ { text: "Alex", value: 1, color: "#f8a398" }, { text: "Bob", value: 2, color: "#51a0ed" }, { text: "Charlie", value: 3, color: "#56ca85" } ] } ] }); $("#online").on("change", function() { alert("Online: " + this.checked); $("#scheduler").data("kendoScheduler").dataSource.online(this.checked); }); }); </script></body></html>
Any help or hint how to get around this is highly appreciated.
Thank's in advance.
Kind regards,
Chris
5 Answers, 1 is accepted
Hello Christian,
Thanks for the report and the sample. We were able to observe the issue locally and to address it. The fix will be available in the next internal build. Meanwhile, as a temporary workaround, you could use a custom offline storage, where to call DataSource reader serialize method when saving the data, similar to the following:
var key = "hs-scheduler-offlinetest";var ds = new kendo.data.SchedulerDataSource({ offlineStorage: { getItem: function() { return JSON.parse(localStorage.getItem(key)); }, setItem: function(item) { localStorage.setItem(key, kendo.stringify(ds.reader.serialize(item))); } }, /*..*/});Rosen
Telerik
Rank 1
Hello Patrick,
Indeed, the issue discussed here has been already resolved. You can check this by yourself with an updated version of the initial test case.
Regards,Rosen
Telerik
Rank 1
Hello Patrick,
My colleague already provide you with an answer in the forum post you have opened. If you have additional comments please continue the discussion there.
Regards,Rosen
Telerik