Composed forms

Composed forms are ideal when you need to manage multiple instances of the same form. The number of forms doesn’t need to be known in advance — new instances can be added or removed at any time.

The core building block of this system is the GladeComposedModel, which maintains and manages a list of individual GladeModel or even another GladeComposedModel instances contained within the composed form.

Because GladeComposedModel extends ChangeNotifier, any dependent widgets automatically rebuild when the model changes.

Using a composed model

Composed models behave just like ordinary GladeModel objects — they are even provided with the same GladeModelProvider and consumed with GladeFormBuilder:

GladeModelProvider(
  create: (context) => MyComposedModel([MyFormModel()]),
  child: GladeFormBuilder<MyComposedModel>(
    builder: (context, composedModel, child) => ...
  ),
)

Managing contained models

You can dynamically add or remove form models:

composedModel.addModel(model);
composedModel.removeModel(model);

Whenever any contained form model changes — or a model is added or removed — the entire composed form builder rebuilds to reflect the updated list.

Rendering multiple identical forms

Since all form models within a composed model share the same type, it's often helpful to automatically generate the same form widget for each model. This is where GladeComposedListBuilder comes in. It iterates through all models and builds the appropriate form widget for each one.