But that's enough about the past. Lets talk about how to extend it.

How Do I Use It

Step 1 - Create the new picker class

Create a new class that extends one of the following base classes.

BasePicker - Used for synchronous data sources

public class ExamplePicker : BasePicker {

    public override Guid Key => new Guid("21696b2b-67fd-47a7-994f-596768e7ea17");
    public override string Name => "Example"; //This the used to identify the picker when creating a custom picker data type instance.

    public override IEnumerable<PickerOption> Children(string id, string culture) {
        ...
    }

    public override IEnumerable<PickerOption> GetInfo(IEnumerable<string> ids, string culture) {
        ...
    }

    public override IEnumerable<PickerOption> Search(string searchTerm, string culture) {
        ...
    }
}

BaseAsyncPicker - Used for asynchronous data sources

public class ExampleAsyncPicker : BaseAsyncPicker {

    public override Guid Key => new Guid("2470e2dd-b784-4ef2-a879-cffd65a494e5");
    public override string Name => "Example Async"; //This the used to identify the picker when creating a custom picker data type instance.

    public override Task<IEnumerable<PickerOption>> ChildrenAsync(string id, string culture) {
        ...
    }

    public override Task<IEnumerable<PickerOption>> GetInfoAsync(IEnumerable<string> ids, string culture) {
        ...
    }

    public override Task<IEnumerable<PickerOption>> SearchAsync(string searchTerm, string culture) {
        ...
    }
}

The Children and ChildrenAsync methods are used to content tree in the picker, where the id is the id of the parent content. The root id will always be "-1" This is the same approach umbraco uses for its TreeControllers (see here).

The GetInfo and GetInfoAsync methods are used to retrieve data about the currently selected items. This is needed since the control only stores the id, similar to how umbraco content pickers store a udi and pull in the relevent information from that.

The Search and SearchAsync methods are used to return a list of options matching the provided searchTerm.

See the code for the PickerPicker for a full implementation of a picker. This is the picker used to select the picker when creating the data type instance.

Step 2 - Create the custom picker instance

Create a new data type like usual, select the newly created picker for the picker property in the configuration and check "Allow Multiple" if more than one selection will be allowed at a time.

And that's all there is to it. For those that are interested there are two nuget packages for this package.

• Bonsai.CustomPicker.Backoffice - This package contains everything needed to use and extend the picker.
• Bonsai.CustomPicker.Core - This contains only the application dlls for developers to create new pickers without adding the app_plugin files.