App Extension Index API

This page refers to src/index.js file, which is executed on quasar dev and quasar build. This is the main process where you can modify the build to suit the needs of your App Extension. For instance, registering a boot file, modifying the webpack process, registering CSS, registering a UI component, registering a Quasar CLI command, etc.

Example of basic structure of the file:

// can be async
export default function (api) {
  // props & methods for "api" Object described below
}

api.ctx

Same as the ctx from the /quasar.config file. Helps you make decisions based on the context in which quasar dev or quasar build runs.

Example: You might want to use one of the api methods if running for electron mode only.

if (api.ctx.dev === true && api.ctx.mode.electron === true) {
  api.beforeDev((api) => {
    // do something when running quasar dev and
    // with Electron mode
  })
}

api.engine

Contains the Quasar CLI engine (as String) being used. Examples: @quasar/app-vite or @quasar/app-webpack.

api.hasVite

Boolean - is running on @quasar/app-vite or not.

api.hasWebpack

Boolean - is running on @quasar/app-webpack or not.

api.extId

Contains the ext-id (String) of this App Extension.

api.prompts

Is an Object which has the answers to the prompts when this App Extension got installed. For more info on prompts, check out Prompts API.

api.resolve

Resolves paths within the app on which this App Extension is running. Eliminates the need to import path and resolve the paths yourself.

// resolves to root of app
api.resolve.app('src/my-file.js')

// resolves to root/src of app
api.resolve.src('my-file.js')

// resolves to root/public of app
// (@quasar/app-webpack v3.4+ or @quasar/app-vite v1+)
api.resolve.public('my-image.png')

// resolves to root/src-pwa of app
api.resolve.pwa('some-file.js')

// resolves to root/src-ssr of app
api.resolve.ssr('some-file.js')

// resolves to root/src-cordova of app
api.resolve.cordova('config.xml')

// resolves to root/src-electron of app
api.resolve.electron('some-file.js')

// resolves to root/src-electron of app
api.resolve.electron('some-file.js')

// resolves to root/src-bex of app
api.resolve.bex('some-file.js')

api.appDir

Contains the full path (String) to the root of the app on which this App Extension is running.

api.hasTypescript
@quasar/app-vite 1.6+

@quasar/app-webpack 3.11+

/**
 * @return {Promise<boolean>} host project has Typescript active or not
 */
await api.hasTypescript()

api.hasLint
@quasar/app-vite 1.6+

@quasar/app-webpack 3.11+

/**
 * @return {Promise<boolean>} host project has ESLint or not
 */
await api.hasLint()

api.getStorePackageName
@quasar/app-vite 1.6+

@quasar/app-webpack 3.11+

/**
 * @return {Promise<string|undefined>} 'pinia' | 'vuex' | undefined
 */
await api.getStorePackageName()

api.getNodePackagerName
@quasar/app-vite 1.6+

@quasar/app-webpack 3.11+

/**
 * @return {Promise<'npm' | 'yarn' | 'pnpm' | 'bun'>}
 */
await api.getNodePackagerName()

api.compatibleWith

Ensure the App Extension is compatible with a package installed in the host app through a semver condition.

If the semver condition is not met, then @quasar/app errors out and halts execution.

Example of semver condition: '1.x || >=2.5.0 || 5.0.0 - 7.2.3'.

/**
 * @param {string} packageName
 * @param {string} semverCondition
 */
api.compatibleWith('@quasar/app', '1.x')

if (api.hasVite === true) {
  api.compatibleWith('@quasar/app-vite', '^2.0.0')
}
else {
  api.compatbileWith('@quasar/app-webpack', '^4.0.0')
}

api.hasPackage

Determine if some package is installed in the host app through a semver condition.

Example of semver condition: '1.x || >=2.5.0 || 5.0.0 - 7.2.3'.

/**
 * @param {string} packageName
 * @param {string} (optional) semverCondition
 * @return {boolean} package is installed and meets optional semver condition
 */
if (api.hasPackage('vuelidate')) {
  // hey, this app has it (any version of it)
}
if (api.hasPackage('quasar', '^2.0.0')) {
  // hey, this app has Quasar UI v2 installed
}

api.hasExtension

Check if another app extension is npm installed and Quasar CLI has invoked it.

/**
 * Check if another app extension is installed
 *
 * @param {string} extId
 * @return {boolean} has the extension installed & invoked
 */
if (api.hasExtension(extId)) {
  // hey, we have it
}

api.getPackageVersion

Get the version of a host app package.

/**
 * @param {string} packageName
 * @return {string|undefined} version of app's package
 */
console.log( api.getPackageVersion(packageName) )
// output examples:
//   1.1.3
//   undefined (when package not found)

api.extendQuasarConf

Extends quasar.config file

/**
 * @param {function} fn
 *   (cfg: Object, ctx: Object) => undefined
 */
api.extendQuasarConf ((conf, api) => {
  // do something with quasar.config file:
  // add, change anything
})

api.extendQuasarConf ((conf, api) => {
  if (api.hasVite === true) {
    // do something with quasar.config file that is specific
    // to @quasar/app-vite
  }
  else { // api.hasWebpack === true
    // do something with quasar.config file that is specific
    // to @quasar/app-webpack
  }
})

Registering boot and css files

export default function (api, ctx) {
  api.extendQuasarConf((conf, api) => {
    // make sure my-ext boot file is registered
    conf.boot.push('~quasar-app-extension-my-ext/src/boot/my-ext-bootfile.js')

    if (api.hasVite !== true) {
      // make sure boot file transpiles
      conf.build.transpileDependencies.push(/quasar-app-extension-my-ext[\\/]src[\\/]boot/)
      // if boot file imports anything, make sure that
      // the regex above matches those files too!
    }

    // make sure my-ext css goes through webpack
    conf.css.push('~quasar-app-extension-my-ext/src/component/my-ext.sass')
  })
}

TIP

Notice the tidle (~) in front of the paths. This tells Quasar CLI that the path is a dependency from node_modules instead of a relative path to App Extension index script file.

api.registerCommand

Register a command that will become available as quasar run <ext-id> <cmd> [args] (or the short form: quasar <ext-id> <cmd> [args]).

/**
 * @param {string} commandName
 * @param {function} fn
 *   ({ args: [ string, ... ], params: {object} }) => ?Promise
 */
api.registerCommand('start', ({ args, params }) => {
  // do something here

  // this registers the "start" command
  // and this handler is executed when running
  // $ quasar run <ext-id> start
})

api.registerDescribeApi

/**
 * @param {string} name
 * @param {string} relativePath
 *   (relative path starting from the file where you have this call)
 */
api.registerDescribeApi(
  'MyComponent',
  './relative/path/to/my/component/file.json'
)

The above will then respond to $ quasar describe MyComponent.

For syntax of such a JSON file, look into /node_modules/quasar/dist/api (in your project folder). Be aware that your JSON must contain a type property (“component”, “directive”, “plugin”). For instance:

{
  "type": "component",
  "props": {
  },
  ...
}

TIP

Always test with the quasar describe command to ensure you got the syntax right and there are no errors.

api.getPersistentConf

Get the internal persistent config of this extension. Returns empty object if it has none.

/**
 * @return {object} cfg
 */
api.getPersistentConf()

api.setPersistentConf

Set the internal persistent config of this extension. If it already exists, it is overwritten.

/**
 * @param {object} cfg
 */
api.setPersistentConf({
  // ....
})

api.mergePersistentConf

Deep merge into the internal persistent config of this extension. If extension does not have any config already set, this is essentially equivalent to setting it for the first time.

/**
 * @param {object} cfg
 */
api.mergePersistentConf({
  // ....
})

api.beforeDev

Prepare external services before $ quasar dev command runs, like starting some backend or any other service that the app relies on.