One the of the hardest things in development - IMHO - after naming, is handling State, at least handling it reactively without overs (over-building, over-rendering, over-painting and overhead!).
Let’s get started!
flutter create geo_tag_diary
Open it in your favorite editor, I personally like VSCode, so
code geo_tag_diary, then add
flutter_redurx in your
dependencies key at
pubspec.yaml. Let you editor get the dependencies again or run in the project folder:
flutter packages get.
Now let’s create a very basic app just to see it working in the device/emulator/simulator (you name it).
lib/app.dart file and add the contents:
And replace everything at
Run the app, you should be seeing
It works on the center of the screen. And you know what this means, it means our greenfield is working!
Let’s change it a little bit so we can see some Flutter-ReduRx magic happening.
First, we create the class that will represent our State, I’ll call it
Diary and place it at
Then we change
lib/main.dart to create the initial State, give it to a Store and give the Store to a Provider:
Flutter-ReduRx is a companion between Flutter’s bindings (Provider & Connect) and ReduRx state management (thought Store & Action).
Let’s see what this
Connect means in the new
lib/app.dart. Please, read the comments on the code:
Right, but all of this could just be replaced by the new message on the greenfield version…
We are going to see the why now!
Mutating the State with Actions
Actions are the last concept here and will close de Flux model.
Let’s create an Action that mutates our previous initial State by a new
To dispatch this Actions we can call
dispatch method on the
Store. Pay attention to the comments again, please.
And note that we changed
lib/app.dart to handle more components on a
Pretty cool! But life isn’t made about hard-coded constants. We talk to databases, another applications and services in general…
Here comes AsyncActions
Just like Actions, but with the power of Dart’s Async constructs.
Let’s improve our Diary with cool random quotes to make your day greater. I’ll be using Tadas Talaikis API (no good reason, just Googled about “free quote api”) and HTTP abstraction from http package. The
lib/actions.dart should look like:
We should update
lib/app.dart to call our newly created AsyncAction. As always, please continue the read by taking a look at the comments on the code:
Why this is called “GeoTagDiary” and there is a “part 1”? Because one single String is easy, there is more to come! Stay tuned!
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