What Are NativeScript Plugins
A NativeScript plugin is any npm package, published or not, that exposes a native API via JavaScript and consists of the following elements.
- A
package.jsonfile which contains the following metadata: name, version, supported runtime versions, dependencies and others. For more information, see thepackage.jsonSpecification section. - One or more CommonJS modules that expose a native API via a unified JavaScript API. For more information about Common JS modules, see the CommonJS Wiki.
- (Optional) Descriptions of permissions, features or other configurations required or used by your plugin inside a pre-compiled Android native library containing an
AndroidManifest.xmlor anInfo.plistfile for Android and iOS, respectively. For more information about Android native libraries, see the Android permissions and resources section. - (Optional) Native Android libraries and the native Android
include.gradleconfiguration file which describes the native dependencies. For more information, see theinclude.gradleSpecification section. - (Optional) Native iOS libraries and the native
build.xcconfigconfiguration file which describes the native dependencies. For more information, see thebuild.xcconfigSpecification section.
The plugin must have the directory structure, described in the Directory Structure section.
Create a Plugin
If the NativeScript framework does not expose a native API that you need, you can develop a plugin which exposes the required functionality. When you develop a NativeScript plugin, keep in mind the following requirements.
- The plugin must be a valid npm package.
- The plugin must expose a built-in native API or a native API available via custom native libraries.
- The plugin must be written in JavaScript and must comply with the CommonJS specification. If you are using a transpiler (e.g. from TypeScript), make sure to include the transpiled JavaScript files in your plugin.
- The plugin name should be postfixed with
nativescript,tns, or thenskeywords (e.g., likenativescript-cameraortns-core-modules). - The plugin directory structure must comply with the specification described below.
- The plugin must contain a valid
package.jsonwhich complies with the specification described below. - If the plugin requires any permissions, features or other configuration specifics, it must contain an
Info.plistfor iOS or a compiled library with anAndroidManifest.xmlfile for Android which describe them. For more information about Android native libraries, see the Android permissions and resources section. - If the plugin depends on other native libraries, it must contain a valid
include.gradleorbuild.xcconfigfile, which describes the dependencies.
Directory Structure
NativeScript plugins which consist of one CommonJS module might have the following directory structure.
nativescript-my-plugin/
└── src
├── index.js
├── package.json
└── platforms/
├── android/
│ └── nativescript-my-plugin.aar (containing custom resources or permissions)
└── ios/
└── Info.plist
NativeScript plugins which consist of multiple CommonJS modules might have the following directory structure.
nativescript-my-plugin/
└── src
├── index.js
├── package.json
├── MyModule1/
│ ├── index1.js
│ └── package.json
├── MyModule2/
│ ├── index2.js
│ └── package.json
└── platforms/
├── android/
│ └── nativescript-my-plugin.aar (containing custom resources or permissions)
└── ios/
└── Info.plist
-
src: Putting your source in sub-folder is required for local LiveSync debugging. Older plugins should be updated to move their source code in to a subfolder. -
index.js: This file is the CommonJS module which exposes the native API. You can use platform-specific*.[platform].jsfiles. For example:index.ios.jsandindex.android.js. During the plugin installation, the NativeScript CLI will copy the platform resources to thetns_modulessubdirectory in the correct platform destination in theplatformsdirectory of your project.
Alternatively, you can give any name to this CommonJS module. In this case, however, you need to point to this file by setting themainkey in thepackage.jsonfor the plugin. For more information, see Folders as Modules. -
package.json: This file contains the metadata for your plugin. It sets the supported runtimes, the plugin name and version and any dependencies. Thepackage.jsonspecification is described in detail below. -
platforms/android/native-library.aarCompiled native libraries (*.aarfiles) contain resources, code and any specific configuration changes, like permissions, required for your plugin to work. For more information about Android native libraries, see the Android permissions and resources section. -
platforms\ios\Info.plist: This file describes any specific configuration changes required for your plugin to work. For example, required permissions. To your convenience, all configurations that are applicable via XCode Info tab and are saved in application's Info.plist file can also be applied manually for plugins directly in the Info.plist. For more information about the format ofInfo.plist, see About Information Property List Files.
During the plugin installation, the NativeScript CLI will merge the pluginInfo.plistwith theInfo.plistfor your project. The NativeScript CLI will not resolve any contradicting or duplicate entries during the merge. After the plugin is installed, you need to manually resolve such issues.
NativeScript plugins which contain both native Android and iOS libraries might have the following directory structure.
nativescript-my-plugin/
└── src
├── ...
└── platforms/
├── android/
│ ├── MyLibraryOne.jar
│ ├── MyLibraryTwo.aar
│ ├── include.gradle
└── ios/
├── MyiOSFramework.framework
├── build.xcconfig
├── Podfile
├── Info.plist
├── MyStaticiOSLibrary.a
└── include/
└── MyStaticiOSLibrary/
└── ...
-
platforms\android: This directory contains any native Android libraries packaged as*.jarand*.aarpackages. These native libraries can reside in the root of this directory or in a user-created sub-directory. During the plugin installation, the NativeScript CLI will configure the Android project inplatforms\androidto work with the plugin. -
platforms\android\include.gradle: This file modifies the native Android configuration of your NativeScript project such as native dependencies, build types and configurations. For more information about the format ofinclude.gradle, seeinclude.gradlefile. -
platforms\ios: This directory contains native dynamic iOS Cocoa Touch Frameworks (.framework) and Cocoa Touch Static Libraries (.a). During the plugin installation, the NativeScript CLI will copy these files tolib\iOSin your project and will configure the iOS project inplatforms\iosto work with the libraries. If the library is written in Swift, only APIs exposed to Objective-C are exposed to NativeScript. In case the plugin contains a Cocoa Touch Static Library (.a), you must place all public headers (.h) underinclude\<Static Library Name>\. Make sure that the static libraries are built at least for the following processor architectures - armv7, arm64, i386. -
platforms\ios\build.xcconfig: This file modifies the native iOS configuration of your NativeScript project such as native dependencies and configurations. For more information about the format ofbuild.xcconfig, seebuild.xcconfigfile. -
platforms\ios\Podfile: This file describes the dependency to the library that you want to use. For more information, see the CocoaPods article.
Package.json Specification
Every NativeScript plugin should contain a valid package.json file in its root. This package.json file must meet the following requirements.
- It must comply with the npm specification.
Thepackage.jsonmust contain at leastnameandversionpairs. You will later use the plugin in your code by requiring it by itsname. - It must contain a
nativescriptsection which describes the supported NativeScript runtimes and their versions. This section can be empty. If you want to define supported platforms and runtimes, you can nest aplatformssection. In thisplatformssection, you can nestiosandandroidkey-value pairs. The values in these pairs must be valid runtime versions or ranges of values specified by a valid semver(7) syntax. - If the plugin depends on other npm modules, it must contain a
dependenciessection as described here.
The NativeScript CLI will resolve the dependencies during the plugin installation.
The following is an example of a package.json file for a NativeScript plugin which supports the 1.0.0 version or above of the iOS runtime and the 1.1.0 version or above of the Android runtime.
{
"name": "nativescript-my-plugin",
"version": "0.0.1",
"nativescript": {
"platforms": {
"ios": "4.0.0",
"android": "4.1.0"
}
}
}
The above configuration states that the plugin requires iOS runtime version 4.0.0 and up or Android runtime version 4.1.0 and up.
Note In case your plugin supports only iOS or Android, make sure to remove the platform which is not supported.
Include.gradle Specification
Every NativeScript plugin, which contains native Android dependencies, should also contain a valid include.gradle file in the root of its platforms\android directory. This include.gradle file must meet the following requirements.
- It must contain its own configuration.
- It might contain native dependencies required to build the plugin properly.
- Any native dependencies should be available in jcenter or from the Android SDK installed on your machine.
IMPORTANT: If you don't have an
include.gradlefile, at build time, gradle will create a default one containing all default elements.
Include.gradle Example
//default elements
android {
productFlavors {
"nativescript-my-plugin" {
dimension "nativescript-my-plugin"
}
}
}
//optional elements
dependencies {
implementation "groupName:pluginName:ver"
}
Android permissions and resources
There are two ways to add permissions and resources for your plugin.
Using a native Android project
If you want your plugin to use special permissions, have custom resources or just want to write some native Java code to be accessed later from the JavaScript/Typescript implementation, you should create a native Android project for your plugin, compile it to an .aar file and put it in the src/platforms/android directory of the plugin package. The easiest way to do this is using Android Studio. The project can contain the following files:
- project/src/main/
AndroidManifest.xml: This file describes any specific configuration changes required for your plugin to work. For example: required permissions. For more information about the format ofAndroidManifest.xml, see App Manifest. - project/src/main/
res: (Optional) This directory contains resources declared by theAndroidManifest.xmlfile. You can look at its structure here. - project/src/main/
java: (Optional) This directory contains Java code sources.
For a more complete Android library project overview visit the Android Documentation.
Using the NativeScript CLI plugin complier
In previous versions of the the NativeScript CLI it was possible to add permissions and resources for Android without a separate native library (.aar file). If you have an older plugin and your AndroidManifest.xml file and res directory are located in platforms/android, then you can compile them with a CLI command. Open a terminal, go to the src directory of the plugin and execute:
tns plugin build
This will create an .aar file in the platforms/android directory, which will contain the compiled manifest and resources and should be included in the plugin package instead of them. If you keep AndroidManifest.xml and res resources in your package, the NativeScript will internally run the tns plugin build command when it builds the native application, which will slow down the process for all users of your plugin. This is why the recommended approach is to have an .aar library in the platforms/android directory of the plugin package instead of plain manifest xml and resource files.
Build.xcconfig Specification
Every NativeScript plugin, which contains native iOS dependencies, can also contain a valid build.xcconfig file in the root of its platforms\ios directory. This build.xcconfig file might contain native dependencies required to build the plugin properly.
Build.xcconfig Example
OTHER_LDFLAGS = $(inherited) -framework "QuartzCore" -l"sqlite3"
Metadata filtering usage specifications
Application author can opt-in for native metadata filtering. Plugins should supply their metadata filtering rules in platforms/android/native-api-usage.json and platforms/ios/native-api-usage.json files respectively. For more detailed description of this feature read this article
Install a Plugin
To install a plugin for your project, inside your project, run the following command.
tns plugin add <Plugin>
Valid Plugin Sources
You can specify a plugin by name in the npm registry, local path or URL. The following are valid values for the <Plugin> attribute.
- A
<Name>or<Name>@<Version>for plugins published in the npm registry. - A
<Local Path>to the directory which contains the plugin source files and itspackage.jsonfile. - A
<Local Path>to a.tar.gzarchive containing a directory with the plugin and itspackage.jsonfile. - A
<URL>which resolves to a.tar.gzarchive containing a directory with the plugin and itspackage.jsonfile. - A
<git Remote URL>which resolves to a.tar.gzarchive containing a directory with the plugin and itspackage.jsonfile.
Installation Specifics
The installation of a NativeScript plugin mimics the installation of an npm module.
The NativeScript CLI takes the plugin and installs it to the node_modules directory in the root of your project. During this process, the NativeScript CLI resolves any dependencies described in the plugin package.json file and adds the plugin to the project package.json file in the project root.
If the NativeScript CLI detects any native iOS libraries in the plugin, it copies the library files to the lib\ios folder in your project and configures the iOS-specific projects in platforms\ios to work with the library.
Next, the NativeScript CLI runs a partial prepare operation for the plugin for all platforms configured for the project. During this operation, the CLI copies only the plugin to the tns_modules subdirectories in the platforms\android and platforms\ios directories in your project. If your plugin contains platform-specific JS files, the CLI copies them to the respective platform subdirectory and renames them by removing the platform modifier.
TIP: If you have not configured any platforms, when you run
$ tns platform add, the NativeScript CLI will automatically prepare all installed plugins for the newly added platform.
Finally, the CLI merges the plugin Info.plist file with platforms\ios\Info.plist in your project. The plugin AndroidManifest.xml will be merged with platforms\android\AndroidManifest.xml later, at build time.
IMPORTANT: Currently, the merging of the platform configuration files does not resolve any contradicting or duplicate entries.
Use a Plugin
To use a plugin inside your project, you need to add a require in your app.
var myPlugin = require("nativescript-my-plugin");
This will look for a nativescript-my-plugin module with a valid package.json file in the tns_modules directory. Note that you must require the plugin with the value for the name key in the plugin package.json file.
Remove a Plugin
To remove a plugin from your project, inside your project, run the following command.
tns plugin remove <Plugin>
You must specify the plugin by the value for the name key in the plugin package.json file.
Removal Specifics
The removal of a NativeScript plugin mimics the removal of an npm module.
The NativeScript CLI removes any plugin files from the node_modules directory in the root of your project. During this process, the NativeScript CLI removes any dependencies described in the plugin package.json file and removes the plugin from the project package.json file in the project root.
IMPORTANT: For iOS, this operation does not remove files from the
platforms\iosdirectories and native iOS libraries, and does not unmerge theInfo.plistfile. For Android, this operation takes care of removing any plugin files located inplatforms\android.
Manual Steps After Removal
After the plugin removal is complete, make sure to remove any leftover native iOS library files from the lib\ios directory in the root of the project. Update the iOS-specific projects in platforms\ios to remove any dependencies on the removed native libraries.
Next, you need to run the following command.
tns prepare <Platform>
Make sure to run the command for all platforms configured for the project. During this operation, the NativeScript CLI will remove any leftover plugin files from your platforms\ios directory.
TIP: Instead of
$ tns prepareyou can run$ tns build,$ tns run,$ tns deployor$ tns emulate. All these commands run$ tns prepare.
Next, open your platforms\ios\Info.plist file and remove any leftover entries from the plugin Info.plist file.
Finally, make sure to update your code not to use the uninstalled plugin.