Update en-US.mdx #5
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docs: enhance didChangeDependencies() & didUpdateWidget() explanations - Simplify definitions for beginners with concrete examples - Clarify where to place custom code (before/after `super` call) when overriding
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| title: What are `StatefulWidget` Lifecycle methods. Explain briefly. | |||
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| - **setState() method:** This method notifies the framework that the internal state of this object has changed. The provided callback must be synchronous which might impact the user interface in the subtree. The framework schedules a build() for this current State object. | ||
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| - **deactivate() method:** The framework calls this method when the State is removed from the tree, temporarily or permanently. | ||
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| - **dispose() method:** This method is called when the State is removed from the tree, permanently. After the dispose() method is called, the State object is considered unmounted. Subclasses should override this method to release any resources retained by this object. | ||
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| # NOTE - |
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| - **Initialization methods**: `super` **first**, then your code | ||
| - **Teardown methods**: your code **first**, then `super` | ||
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| ## Initialization Methods |
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| # NOTE - | ||
| - When overriding Flutter lifecycle methods, it’s crucial to know **where** to place your own code relative to the `super.methodName()` call. | ||
| ## The rule of thumb is: |
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| These methods prepare both Flutter’s internals and your own state. Always let Flutter finish its setup before you start: | ||
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| ### `initState()` |
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| ### `didChangeDependencies()` |
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| ``` | ||
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| ### `didUpdateWidget()` |
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| ## Teardown Methods |
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| - **createState() method:** Whenever a StatefulWidget is created, the framework calls this method to create fresh State objects. This method must be overridden. | ||
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| - **initState() method:** This method is the first method that is called while creating a StatefulWidget class. Here we allocate our resources, which means we can initialize our variable, data, and properties. | ||
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| - **didChangeDependencies() method:** This method is called just after initState() method when a dependency of this State object changes. For example, if the previous build was referencing an InheritedWidget that changes, this method notifies the object to change. Generally, subclasses don't override didChangeDependencies() method because the framework calls build() methods after dependency change. But to do some expensive work, let's say some network calls, the method is preferred over doing everything on build() method itself. | ||
| - **didChangeDependencies() method:** Called immediately after `initState()` and again whenever an `InheritedWidget` that this `State` depends on changes (e.g., `MediaQuery`, `Theme`, or a localized resource). Ideal for context-dependent initialization or expensive work that shouldn’t run on every build. | ||
| ```dart |
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| - **build() method:** Every time the widget is rebuilt, the build() method is used. This can happen after calling initState(), didChangeDependencies(), or didUpdateWidget(), or after changing the state with a call to setState(). | ||
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| - **didUpdateWidget() method:** This method is called whenever the widget configuration changes. This method exists for triggering side-effects when one of the parameters in the StatefulWidget changes. A typical example is implicitly animated widgets. | ||
| - **didUpdateWidget() method:** Called whenever the parent widget rebuilds and supplies a new instance of this widget with updated properties. Override it to compare oldWidget vs. widget and trigger side-effects when specific parameters change, without recreating the whole State. | ||
| ```dart |
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docs: enhance didChangeDependencies() & didUpdateWidget() explanations
supercall) when overriding