Kendo Ui DataSource Add Function not working properly

Question

I defined a Kendo Data Source as below. It is populating values in a ListView. ``` var datasourceAppList = new kendo.data.DataSource({ transport: { create: function(options){ //alert(options.data.desc); alert(options.data.desc); var localData = JSON.parse(localStorage.getItem("LsAppList")); localData.push(options.data); localStorage.setItem("LsAppList", JSON.stringify(localData)); //localStorage["LsAppList"] = JSON.stringify(localData); options.success(localData); }, read: function(options){ var localData = JSON.parse(localStorage["LsAppList"]); options.success(localData); }, update: function(options){ var localData = JSON.parse(localStorage["LsAppList"]); for(var i=0; i<localData.length; i++){ if(localData[i].extappId == options.data.extappId){ localData[i].desc = options.data.desc; localData[i].deviceNo = options.data.deviceNo; localData[i].validationKey = options.data.validationKey; } } localStorage["grid_data"] = JSON.stringify(localData); options.success(localData); }, destroy: f…

Accepted Answer

It is actually a combined problem:

You `schema` definition is:

```
schema: {
    model: {
        extappId: "ID",
        fields: {
            extappId: { type: "number" },
            desc: { type: "string" },
            deviceNo: { type: "number" },
            validationKey: { type: "string" }
        }
    }
 }
```

It says `extappId: "ID"`... what is this? Do you want to say that `extappId` is the `id` of that record? If so, the actual definition should be:

```
schema: {
    model: {
        id: "extappId",
        fields: {
            extappId: { type: "number" },
            desc: { type: "string" },
            deviceNo: { type: "number" },
            validationKey: { type: "string" }
        }
    }
 }
```

What happens here is not being (correctly) defined the `id`, KendoUI expects that `id` is actually `id` and since this is not being set during the `create` next time that you `sync` it tries to save it, it is equivalent to:

```
datasourceAppList.add({ extappId: 9905, desc: "test", deviceNo: 5, validationKey: "CACACACA"});
datasourceAppList.add({ extappId: 9908, desc: "harvest", deviceNo: 7, validationKey: "ppppppp"});
datasourceAppList.sync();
```

But if you try this, you will see that then `create` is never invoked. Now what happens is that the `id` of the record (i.e. `extappId`) is already defined and not null and so KendoUI believes that is already saved.

For solving this second issue my recommendation is defining the `schema` as:

```
schema: {
    model: {
        id: "ID",
        fields: {
            extappId: { type: "number" },
            desc: { type: "string" },
            deviceNo: { type: "number" },
            validationKey: { type: "string" }
        }
    }
 }
```

Now, the `id` is a field called `ID` and this `ID` should be created on `transport.create` (cannot be set before invoking `add` method).

Then, you set it in `create` and you can use:

```
create: function(options){
    // Set `ID` to kendo.guid
    options.data.ID = kendo.guid();
    alert(options.data.desc);
    var localData = JSON.parse(localStorage.getItem("LsAppList"));
    localData.push(options.data);
    localStorage.setItem("LsAppList", JSON.stringify(localData)); //localStorage["LsAppList"] = JSON.stringify(localData); 
    options.success(localData);
},
```

Check it here : http://jsfiddle.net/OnaBai/n7sNd/3/

Kendo Ui DataSource Add Function not working properly

Solution

Problem