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39 changes: 39 additions & 0 deletions docs/generated-code/component-gen-code.md
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---
title: Components
slug: /generated-code/component-model
sidebar_position: 6
---

# Generated Code: Components

Similar to a [**Page**](pages-generated-code.md), when creating a **[component](../resources/ui/components/intro-components.md)** in FlutterFlow, it automatically generates two files: a `Widget` class and a `Model` class.

:::info[Prerequisites]
This guide uses examples from the generated code of the **[EcommerceFlow demo app](https://bit.ly/ff-docs-demo-v1)**. To view the generated code directly, check out the **[Github repository](https://github.com/FlutterFlow/sample-apps/tree/main/ecommerce_flow)**.
:::

## ComponentModel class

`ComponentModel` classes are responsible for managing the state and behavior of individual components used within a page. These classes extend the `FlutterFlowModel` class, providing a consistent structure and shared functionality across all component models. This ensures that each component's state is isolated and reusable, making the app easier to maintain and scale.

The lifecycle of a `ComponentModel` and its associated widget class follows the same structure as a page. For more details, refer to the documentation on **[Generated Pages](pages-generated-code.md)**.

### onComponentLoad Action: Generated Code

When you define actions for the `onComponentLoad` action trigger of a component, these actions are added inside an `addPostFrameCallback` method within the page's `initState` method. This ensures that the actions are executed only after the initial widget tree is built.

```js
@override
void initState() {
super.initState();
_model = createModel(context, () => ProductListPageModel());

// On component load action.
SchedulerBinding.instance.addPostFrameCallback((_) async {
await _model.updateTotalCost(context);
safeSetState(() {});
});

}
```

109 changes: 109 additions & 0 deletions docs/generated-code/flutterflow-model.md
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---
title: FlutterFlow Model
slug: /generated-code/flutterflow-model
sidebar_position: 4
---

# FlutterFlow Model

The `FlutterFlowModel` class is an abstract class used in FlutterFlow to provide a unified and extensible structure for managing state and behavior of widgets (both pages and components). It encapsulates **initialization, state management,** and **disposal** logic, making it easier to handle the lifecycle of widgets and their models.

FlutterFlow automatically generates the `flutter_flow_model.dart` file, which contains the `FlutterFlowModel` class and utility methods like `wrapWithModel()` and `createModel()`.

The diagram below illustrates how these utility classes and methods are utilized in a widget or model class:


![page-generated.png](imgs/page-generated.png)
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In '![page-generated.png]' image, I made some alignment fixes in Figma directly. You can check and replace if it looks good to you.


When a component is added to your page (and every component you create [generates both a widget and a model class)](component-gen-code.md), the flow below explains how the utility classes are used when there is a child component:

![page-component-generated.png](imgs/page-component-generated.png)
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In '![page-component-generated.png]' image, I made some alignment fixes in Figma directly. You can check and replace if it looks good to you.


<p></p>

Here’s a breakdown of the lifecycle of `FlutterFlowModel` class:

## Initialization
Ensures the model is initialized **only once** and is tied to the `BuildContext` and the widget it is associated with.

```js
abstract class FlutterFlowModel<W extends Widget> {
// Initialization methods
bool _isInitialized = false;
void initState(BuildContext context);
void _init(BuildContext context) {
if (!_isInitialized) {
initState(context);
_isInitialized = true;
}
if (context.widget is W) _widget = context.widget as W;
_context = context;
}
```


## Widget & Context references

Provides references to the associated widget and its `BuildContext`.

```js
// The widget associated with this model. This is useful for accessing the
// parameters of the widget, for example.
W? _widget;
W? get widget => _widget;

// The context associated with this model.
BuildContext? _context;
BuildContext? get context => _context;
```

`_widget` and `_context` (private fields) store the widget and context references. `widget` and `context` (getters) are the public accessors for `_widget` and `_context`.

## Disposal

Manages the cleanup of resources when the model or widget is disposed.

```js
bool disposeOnWidgetDisposal = true;
void dispose();
void maybeDispose() {
if (disposeOnWidgetDisposal) {
dispose();
}
// Remove reference to widget for garbage collection purposes.
_widget = null;
}
```
The `disposeOnWidgetDisposal` determines whether the model should be disposed when the widget is removed. This defaults to `true` for **pages** and `false` for **components** (as parent models typically manage their child components).

The `maybeDispose()` checks `disposeOnWidgetDisposal` before disposing. It removes the widget reference to aid garbage collection.

## Updates and Change Notification

Allows the model to notify the associated widget or parent component/page when updates occur.

```js
// Whether to update the containing page / component on updates.
bool updateOnChange = false;
// Function to call when the model receives an update.
VoidCallback _updateCallback = () {};
void onUpdate() => updateOnChange ? _updateCallback() : () {};

FlutterFlowModel setOnUpdate({
bool updateOnChange = false,
required VoidCallback onUpdate,
}) =>
this
.._updateCallback = onUpdate
..updateOnChange = updateOnChange;

// Update the containing page when this model received an update.
void updatePage(VoidCallback callback) {
callback();
_updateCallback();
}
```

## wrapWithModel()

The `wrapWithModel()` method in FlutterFlow links a model to a widget and its child widgets, allowing them to access and manage state. It wraps the widget with a Provider, making the model available throughout the widget tree.
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67 changes: 0 additions & 67 deletions docs/generated-code/page-model.md

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