The modelValue or model can be considered as the ‘aorta’ of our form system. It is the single source of truth; not only for the current state of the form, also for all derived states: interaction, validation, visibility and other states are computed from a modelValue change.
ModelValues are designed to provide the Application Developer a single way of programmatical interaction with the form for an Application Developer.
Application Developers need to only care about interacting with the modelValue on a form control level, via:
Internal/private concepts like viewValue, formattedValue, serializedValue are therefore not recommended as a means of interaction.
For more information about parsing and the Unparseable type, see Formatting and Parsing
model-value-changed events have a
detail object, containing the following meta data:
isTriggeredByUser: a boolean that determines whether a change originated from a user or was triggered programmatically
formPath: an array of FormControls. It contains the path an event follows to go from a 'leaf element' (for instance a lion-input) to a top element (for instance lion-form). An example path could be [lionForm, lionFieldset, lionInput]
initialize: whether this is the first time the event is fired (on first render of the FormControl)