Here's a summary on how to create a shared and a static library with gcc. The goal is to show the basic steps. I do not want to go into the hairy details. It should be possible to use this page as a reference.
If you write plugins for Flutter, you should know that the plugin API was upgraded to 2.0 in Flutter 1.12 to support federated plugins and to make it easier to test your plugin. In Flutter 1.10, Flutter’s pubspec format was updated to allow you to specify which platforms a plugin supports, such as web and macos.
Eventually, the old style of plugin will be deprecated and, in the short term, you will see a warning when the framework detects that you are using an old-style plugin. For information on how to upgrade your plugin, see Supporting the new Android plugins APIs.
Package introduction
Packages enable the creation of modular code that can beshared easily. A minimal package consists of the following:
Note: For a list of dos and don’ts when writing an effective plugin, see the Medium article by Mehmet Fidanboylu, Writing a good plugin.
Package types
Packages can contain more than one kind of content:
Developing Dart packages
The following instructions explain how to write a Flutterpackage.
Step 1: Create the package
To create a Flutter package, use the
--template=package flagwith flutter create :
This creates a package project in the
hello folder with the following content:
Step 2: Implement the package
For pure Dart packages, simply add the functionalityinside the main
lib/<package name>.dart file,or in several files in the lib directory.
To test the package, add unit testsin a
test directory.
For additional details on how to organize thepackage contents,see the Dart library package documentation.
Developing plugin packages
If you want to develop a package that calls intoplatform-specific APIs, you need to develop a plugin package.A plugin package is a specialized version of aDart package that, in addition to the content described above,also contains platform-specific implementations written forAndroid (Kotlin or Java code), iOS (Swift or Objective-C),web (Dart), macos (Dart), or any subset thereof.The API is connected to the platform-specificimplementation(s) using [platform channels][].
Federated plugins
Federated plugins were introduced in Flutter 1.12as a way of splitting support for different platformsinto separate packages. So, a federated plugin can useone package for iOS, another for Android,another for web, and yet another for your car(as an example of an IoT device).Among other benefits, this approach allows adomain expert to extend an existing plugin to work forthe platform they know best.
A federated plugin requires the following packages:
For more information on federated plugins,why they are useful, and how they are implemented,see the Medium article by Harry Terkelsen,How To Write a Flutter Web Plugin, Part 2.
Specifying a plugin’s supported platforms
In Flutter 1.12 and later, plugins can specifythe platforms they support by adding keys to the
platforms map in the pubspec.yaml file.For example, the following pubspec file shows theflutter: map for the hello plugin, which supportsonly iOS and Android:
When adding plugin implementations for more platforms,the
platforms map should be updated accordingly. For example, here’s the map in the pubspec filefor the hello plugin, when updated to add supportfor macOS and web:
Step 1: Create the package
To create a plugin package, use the
--template=plugin flag with flutter create .
Use the
--org option to specify your organization,using reverse domain name notation. This value is usedin various package and bundle identifiers in thegenerated plugin code.
This creates a plugin project in the
hello folderwith the following specialized content:
By default, the plugin project uses Swift for iOS code andKotlin for Android code. If you prefer Objective-C or Java,you can specify the iOS language using
-i and theAndroid language using -a . For example:
Step 2: Implement the package
Daw cassette vst download. As a plugin package contains code for several platformswritten in several programming languages,some specific steps are needed to ensure a smooth experience.
Step 2a: Define the package API (.dart)
The API of the plugin package is defined in Dart code.Open the main
hello/ folder in your favorite Flutter editor.Locate the file lib/hello.dart .
Step 2b: Add Android platform code (.kt/.java)
We recommend you edit the Android code using Android Studio.
Before editing the Android platform code in Android Studio,first make sure that the code has been built at least once(in other words, run the example app from your IDE/editor,or in a terminal execute
cd hello/example; flutter build apk ).
Then use the following steps:
The Android platform code of your plugin is located in
hello/java/com.example.hello/HelloPlugin .
You can run the example app from Android Studio bypressing the run (▶) button.
How To Create A Library In Dev C OnlineStep 2c: Add iOS platform code (.swift/.h+.m)
We recommend you edit the iOS code using Xcode.
Before editing the iOS platform code in Xcode,first make sure that the code has been built at least once(in other words, run the example app from your IDE/editor,or in a terminal execute
cd hello/example; flutter build ios --no-codesign ).
Then use the following steps:
The iOS platform code for your plugin is located in
Pods/Development Pods/hello/././example/ios/.symlinks/plugins/hello/ios/Classes in the Project Navigator.
You can run the example app by pressing the run (▶) button.
Step 2d: Connect the API and the platform code
Finally, you need to connect the API written in Dart code withthe platform-specific implementations.This is done using a platform channel,or through the interfaces defined in a platforminterface package.
Testing your plugin
As of Flutter 1.12, it is now easier to write code totest your plugin. For more information, seeTesting your plugin, a section inSupporting the new Android plugins APIs.
Adding documentation
It is recommended practice to add the following documentationto all packages:
API documentation
When you publish a package,API documentation is automatically generated andpublished to pub.dev/documentation.For example, see the docs for
device_info .
If you wish to generate API documentation locally onyour development machine, use the following commands: Precision tune auto care dayton oh 45405.
For tips on how to write API documentation, seeEffective Dart Documentation.
Adding licenses to the LICENSE file
Individual licenses inside each LICENSE file shouldbe separated by 80 hyphens on their own on a line.
If a LICENSE file contains more than one component license,then each component license must start with the names of thepackages to which the component license applies,with each package name on its own line, and thelist of package names separated from the actuallicense text by a blank line.(The packages need not match the names of the pub package.For example, a package might itself contain code frommultiple third-party sources, and might need to includea license for each one.)
The following example shows a well-organized license file:
How To Include Library In Dev C++
Here is another example of a well-organized license file:
Here is an example of a poorly-organized license file:
Another example of a poorly-organized license file:
Publishing your package
Tip: Have you noticed that some of the packages and plugins on pub.dev are designated as Flutter Favorites? These are the packages published by verified developers and are identified as the packages and plugins you should first consider using when writing your app. To learn more, see the Flutter Favorites program.
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Once you have implemented a package, you can publish it onpub.dev, so that other developers can easily use it.
Prior to publishing, make sure to review the
pubspec.yaml ,README.md , and CHANGELOG.md files to make sure theircontent is complete and correct. Also, to improve thequality and usability of your package (and to make itmore likely to achieve the status of a Flutter Favorite),consider including the following items:
Next, run the publish command in
dry-run modeto see if everything passes analysis:
The next step is publishing to pub.dev,but be sure that you are ready becausepublishing is forever:
For more details on publishing, see thepublishing docs on dart.dev.
Handling package interdependencies
If you are developing a package
hello that depends onthe Dart API exposed by another package, you need to addthat package to the dependencies section of yourpubspec.yaml file. The code below makes the Dart APIof the url_launcher plugin available to hello :
You can now
import 'package:url_launcher/url_launcher.dart' and launch(someUrl) in the Dart code of hello .
This is no different from how you include packages inFlutter apps or any other Dart project.
But if
hello happens to be a plugin packagewhose platform-specific code needs accessto the platform-specific APIs exposed by url_launcher ,you also need to add suitable dependency declarationsto your platform-specific build files, as shown below.
AndroidHow To Create A Library In Dev C In Word
The following example sets a dependency for
url_launcher in hello/android/build.gradle :
You can now
import io.flutter.plugins.urllauncher.UrlLauncherPlugin and access the UrlLauncherPlugin class in the source code at hello/android/src .
How To Add Libraries In Dev C++iOS
The following example sets a dependency for
url_launcher in hello/ios/hello.podspec :
You can now
#import 'UrlLauncherPlugin.h' andaccess the UrlLauncherPlugin class in the source codeat hello/ios/Classes .
Web
All web dependencies are handled by the
pubspec.yaml file like any other Dart package.
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