Thread by @vandadnp

Confused about #Provider in #Flutter? Thread to explain some of the most important concepts
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context.select() is used when you want to watch a specific aspect of a provider and rebuild your widget upon that value changing. It's only useful inside the build() function of your widgets and changes to the selected value will mark the widget as needing to be rebuilt

by using context.select(), you rebuild your widget only if the given aspect of your provider changes, this is specially useful if you have a large provider with many moving parts

When a provider emits an update, such as with notifyListeners(), all selectors will be called by the Provider library, only if the returned value is different from the previously returned value

context.read(): This function allows you to interact with your provider. You should use read() inside your event handlers and not directly inside the build() function. read() internally uses Provider.of<T>(this, listen: false) meaning that it doesn't listen for changes

context.read(): Use read() mainly to send values to your provider and use select() to read values that might not change

context.watch() as its name indicates depends on a given provider up the hierarchy and marks the widget as needing to be rebuilt if the provider

context.watch() allows you to depend on an optional provider using context.watch<ProviderName?>

context.watch() is the same as Provider.of<T>(context) because listen: true is default in .of<T> function

context.watch() should only be used inside build() functions of StatelessWidget and the build() function of State

If you need context.watch() outside build functions, use Provider.of<T> instead

Consumer creates a new Widget and calls the builder with its own BuildContext and wraps itself around the returned widget from the builder

Consumer is useful if the widget returned from the builder parameter depends on the provider before the context itself has access to it

Consumer has a child widget that doesn't get rebuilt when the provider changes

In Consumer, the "child" gets passed to the builder of the consumer and can be reused regardless of changes to the provider