App Extension Development

This section of the docs deals with creating your own App Extensions.

It is assumed you have already installed one of the official App Extensions. Having this experience at your disposal is going to be very valuable when you start building your own App Extensions. If you run into problems, please visit our Discord server’s channel #app-extensions.

Getting started

An App Extension is an npm package. There are two official kits for creating App Extensions:

  1. App Extension (AE) kit
  2. UI kit

App Extension (AE) kit

If your app extension does not involve UI (i.e. does not have components or directives) then use the AE kit. An example of this would be an extension that creates a boot file only.

UI kit

If your app extension does involve UI (i.e. does have components or directives) then use the UI kit. An example of this would be an extension that provides a UI element for use in your app. This has a ui folder for creating your component/directive, a ui/dev Quasar application for testing your component/directive in isolation, and an app-extension folder for creating the App Extension that will be used for injecting your component/directive via the Quasar CLI into a Quasar app. The UI kit can also be used such that your component/directive can also be used with the Quasar Vite plugin or Vue CLI or UMD.

3rd party integration

If your objective is to install a 3rd-party library into Vue, then it depends upon the library…

  • If you also aim to provide some UI components or such that uses that Vue plugin, you should use the UI Kit. This would be a good choice for including something like a Calendar extension.
  • If the only objective is to load it through a simple app.use(SomeVuePlugin) in a boot file, and maybe some config updates and such, the AE Kit may be a better choice. This is a good choice for example for something like including Axios.

Creating the App Extension

$ yarn create quasar
# or
$ npm init quasar

# pick the AppExtension option

It will prompt you about your specific needs. Do you need an install script, an uninstall script, will you be prompting the user with some questions? Pick only what you will be using. You can manually add these later if you decide otherwise.

For the sake of this documentation page, let’s assume we answered with my-ext to the App Extension ext-id question (regarding the prompts above). Remember that the folder name for the App Extension source folder can be different from the actual ext-id. At the end, we will publish our new npm package (quasar-app-extension-my-ext).

Based on your response, Quasar CLI will create a folder for your App Extension’s source code that will have the following structure:

The app-extension kit:

package.json
index.js
# Described in Index API
install.js
# Described in Install API
prompts.js
# Described in Prompts API
uninstall.js
# Described in Uninstall API

The ui kit:

package.json
index.js
# Described in Index API
install.js
# Described in Install API
prompts.js
# Described in Prompts API
uninstall.js
# Described in Uninstall API
package.json
build
# build scripts
dev
# Quasar app for testing component/directive
Component.js
# (optional) Code for your component(s)
Component.sass
# (optional) Sass for your component(s)
Directive.js
# (optional) Code for your directive(s)
Directive.sass
# (optional) Sass for your directive(s)
index.common.js
# CommonJS entry point
index.esm.js
# ESM entry point
index.umd.js
# UMD entry point
vue-plugin.js
# Exports the associated Vue plugin
index.sass
# Exports the associated SASS files

Except for src/index.js (from the app-extension kit) or app-extension/src/index.js (from the ui kit) , all the other files are optional. You can manually add or remove them at any point in time.

When using the UI kit, you will have two npm packages; one for the App Extension and one for the UI module. For testing with the dev app, from the ui folder type yarn dev. Create pages in the dev folder for testing and they will automatically be injected into the test app. Also, check out the scripts section in the package.json to see what you have available. When you yarn build, a dist folder will be created and populated with various types of packages (common, esm, and umd).

App Extension Scripts description

NameDescription
src/prompts.jsHandles the prompts when installing the App Extension
src/install.jsExtends the installation procedure of the App Extension
src/index.jsIs executed on quasar dev and quasar build
src/uninstall.jsExtends the uninstallation procedure of the App Extension

Handling package dependencies

If your App Extension has its own dependencies over some packages in order for it to be able to run (except for packages supplied by Quasar CLI, like “quasar”, “@quasar/extras”, “@quasar/app” – you should use “api.compatibleWith()” for those in your /install.js and /index.js scripts – check Install API and Index API), then yarn/npm installing them into your App Extension folder will supply them into the hosting app.

Example: You are creating a UI component that depends on “my-table” npm package (name is bogus, just for making a point here), then you should yarn/npm install “my-table” in your App Extension folder.

WARNING

Never yarn/npm install packages that are supplied by the Quasar CLI, because App Extensions should not be so intrusive and force the user to use a certain Quasar version. Instead, make use of “api.compatibleWith()” for those, which is equivalent to softly saying “Sorry, you need to install this version of Quasar if you want to take advantage of my App Extension”.

Manually testing

We need to create a Quasar project folder to be able to test it while we develop the extension:

$ yarn create quasar
# or
$ npm init quasar

# pick "App with Quasar CLI"

Install and prompts scripts

TIP

Learn more about what you can do with the Prompts API and the Install API.

Inside the testing Quasar project folder, we manually add our App Extension. Notice that we are not specifying the npm package name (it’s not published yet!) but a path to our App Extension folder where we develop it, since we want to test unpublished work:

$ yarn add --dev file://path/to/our/app/ext/app-extension
# or
$ yarn add --dev link://path/to/our/app/ext/app-extension

You will need to figure out which command works best for your environment.

WARNING

There have been many reports of problems linking via file: and link:. This is outside of Quasar’s reach, but is likely to do with your development environment, aka your mileage with Windows will vary.

We then invoke it. The invoking procedure assumes that the App Extension’s package is already yarn/npm installed (which we did earlier) and skips that step:

# we said our <ext-id> will be "my-ext", so:
$ quasar ext invoke my-ext

This will trigger the installation of our new App Extension. You need to redo these two steps each time you make changes and you want to test them.

Additionally, if you would like to have HMR (hot module reload) capabilities in your test app while developing your App Extension, then your quasar.config.js > devServer > watchFiles would look like this:

// quasar.config.js for
// Quasar CLI with Webpack (@quasar/app-webpack)

devServer: {
  // be sure to change <myextid> below to
  // your App Extension name:
  watchFiles: [
    '/node_modules/quasar-app-extension-<myextid>/*'
  ]
}

@quasar/app-webpack

You might want to extend the Webpack config. Assuming you are using the chainWebpack method, your quasar.config.js > build > chainWebpack should look like this:

chainWebpack (chain) {
  chain.merge({
    snapshot: {
      managedPaths: []
    }
  })
},

@quasar/app-vite

You might want to extend the Vite config. Assuming you are using the extendViteConf method, your quasar.config.js > build > extendViteConf should look like this:

extendViteConf (viteConf, { isClient, isServer }) {
  // do stuff in-place with viteConf
},

Uninstall script

TIP

Learn more about what you can do with the Uninstall API.

Assuming you’ve installed your App Extension following the section above, we can now test the uninstall script (if you have any):

$ quasar ext uninvoke my-ext

The command above similarly does not modify or remove the npm package from package.json and node_modules. It simply calls the uninstall script and removes it from the registered/installed App Extensions list in your testing Quasar app project folder. Your end-user will however call $ quasar ext remove my-ext to uninstall it, which also uninstalls the npm package.

You need to redo these install steps and issue the uninvoke command each time you make changes to the uninstall script and you want to test them.

Index script

In the sections above we described how to test the prompts, install and uninstall scripts. Now it’s time for the index script, which is the heart of your App Extension.

This is where you can tamper with all quasar.config.js options, extend the Webpack configuration, register Quasar CLI commands, start up external services required for developing your app and many more.

As a result, the index script is run each time $ quasar dev and $ quasar build are executed.

In order to test the index script, you can repeat the uninstall and install procedures described above each time you change something in the App Extension script code. But it becomes very tedious. If you are developing on a Unix OS (MacOS, Linux), you can take advantage of the yarn link command which creates a symbolic link from the Quasar testing app’s node_modules folder to the folder of your extension:

$ cd /path/to/app/extension/folder

# we register the extension through yarn
$ yarn link

$ cd /path/to/quasar/testing/app/folder

$ yarn link quasar-app-extension-<ext-id>
# in our demo case, it's this:
# $ yarn link quasar-app-extension-my-ext

Remember that if you need to yarn/npm install any dependencies into your App Extension, then you must also uninstall your App Extension and re-install it in your test app:

$ cd /path/to/app/extension/folder

# run yarn/npm command (install/uninstall, etc)

# then

$ cd /path/to/quasar/testing/app/folder

# Uninstall the app ext
$ quasar ext uninvoke my-ext

# Re-install the app ext
$ quasar ext invoke my-ext

You really only need to quasar ext invoke my-ext (install) the App Extension to re-install it. The above information is for completeness.

WARNING

There have been many reports of problems with yarn link on Windows. This is outside of Quasar’s reach, but is likely to do with your development environment, aka your mileage with Windows will vary.

TIP

Learn more about what you can do with the Index API.

Publishing

When you finalized your App Extension and you’re ready to deploy it, all you need to do is to publish it to the npm repository.

Inside of your App Extension folder, run yarn publish or npm publish. Both do the same thing.

WARNING

It’s important to remember to NOT strip out the quasar-app-extension- prefix from the name property of your extension’s package.json, otherwise Quasar CLI will not recognize it.