TreeList new row disappears on edit

[Daniel]

I have a TreeList control where the data is kept in an array in memory - the user will save manually after editing everything they need to.

One problem I'm facing is that if a new record is created, and then subsequently edited - it will disappear after either Save or Cancel.

I've removed a lot of the code for brevity - but this is a working example of what I have:

https://dojo.telerik.com/tDidtCqZ

Any idea what I'm doing wrong?

[Neli]

Hello,

I've reviewed your shared Dojo example and the issue is related to how the TreeList DataSource handles new items when working with in-memory arrays and custom transport logic, especially when batch mode is enabled and data is not persisted immediately.

Why the New Row Disappears

• When you create a new record and then edit it, the DataSource tracks the item as "new" (isNew()) and/or "dirty". In the current scenario, you have to manually ensure the new item is added to your in-memory array.

You need to make sure that:

• Any new record is immediately added to your in-memory array (dsData) upon creation, not just when you call sync or save.
• The DataSource and your in-memory array stay in sync, so the TreeList does not lose track of newly created items.

Example Fix for the create Transport

Update your create transport function so that every new model is pushed to your dsData array as soon as it is created:

create: function (options) {
    for (let i = 0; i < options.data.models.length; i++) {
        if (options.data.models[i]._x_Added) {
            continue;
        }
        maxId++;
        options.data.models[i]._x_Added = true;
        options.data.models[i]._x_ID = maxId;

        // Add the new item to the in-memory array
        dsData.push(options.data.models[i]);
    }
    options.success(options.data.models);
},

Here you will find the modified Dojo example - https://dojo.telerik.com/KtoYquAR.

I hope this helps. 

Regards,
Neli
Progress Telerik

[Daniel]

Thank you so much Neli - it worked a treat