A widget that allow to fetch a value asynchronously, and then to run another task asynchronously (to submit new value for instance) while updating UI with new value.
Handle all states (loading, errors, onSuccess).
It's actually a mix of FetchBuilder and SubmitBuilder combined.
Typically used for component that needs to fetch a value and then edit that value.
DON'T use this if fetch and submit tasks are not related (prefer using separate FetchBuilder and SubmitBuilder).
Example : an async switch, that fetch the current value, and then can submit the new value.
Use FetcherConfig.fetchingBuilder (while fetching) and FetcherConfig.submittingBuilder (while submitting) on config to customize each loading widget independently.
Tracks elements being edited in its subtree (e.g. a GuardedForm with changes).
May be used to delay a data update while user is editing, so that the input isn't lost when the subtree is recreated.
GuardedForm (and so SubmitFormBuilder) automatically registers to the closest EditingScope when changed.
Nested scopes are supported: an element being edited also marks all ancestor scopes as editing.
Must be placed above the subtree that may be recreated.
Parent scope is resolved once: moving a scope or a GuardedForm to another place in the tree (with a GlobalKey) isn't supported.
Builds builder with value, recreating its subtree (its state is lost) each time value changes,
except while an element is being edited in it (see EditingScope): the displayed value is then kept,
and updated to the latest value when editing ends.
Values are compared with ==: a subtree won't be recreated after a save if the new value equals the previous one.
Inside a FetchBuilder or EventFetchBuilder, keep FetcherConfig.fadeOnDataChange to false (default):
otherwise this widget is recreated on each data and can't keep the displayed value.
Loading and error states also replace this widget (e.g. stream error, refresh with clearDataFirst).
Widget that listen to an EventStream and display data.
It's like FetchBuilder but instead of directly calling a task once, it will listen to a stream and his updates.
Handle all possible states: loading, loaded, errors.
A Form that tracks for changes and may prevent pop.
Current implementation just track if form has been modified once (calling Form.save() doesn't reset status).
Call markAsSaved to reset status (automatically done by SubmitFormBuilder on success).
When changed, registers to the closest EditingScope, until saved or disposed.
A widget that fetch a paginated list of data, page by page.
Handle all states (loading, errors, onSuccess).
Initially just fetch first page, then fetch next page when user scrolls.
T is the type of the data.
P is the type of the pageId (usually String or int).
A widget that allow to run an async task and handle all states (loading, errors, onSuccess).
Design for tasks that is triggered by a user action (like a button press).
Scrolls to the first invalid FormField in the subtree rooted at formContext.
Must be called after Form.validate so that FormFieldState.hasError is up to date.
