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Building Apps

Daniel Chilcott avatar
Written by Daniel Chilcott
Updated over a week ago

Build your own Javascript & React apps that embed directly into the Flowgear Console to create rich user experiences.

Flowgear Apps are able to invoke native and Site-specific Flowgear API's via current users' security context. This permits the Web App to act as a pure front-end with virtually no business logic while Flowgear Workflows provide the business logic and data layers.

This article describes how to build and publish Flowgear Apps.

Requirements

1. NodeJS (available for download at https://nodejs.org/en/download/ ).

2. Visual Studio Code or other text editor.

Run the sample App

1. Clone the Flowgear Samples repository, then open custom-apps\sample-app in Visual Studio Code.

2. Run command npm install via the CMD or Terminal in the project directory (it may take some time as it will need to install packages).

3. Please follow the README for instructions (flowgear-samples/README.md) on how to configure https for localhost to use for debugging the web app. This is required because the console is running in https and to debug the web app embedded in the console it is necessary that the app is also locally configured for https.

4. Run command npm start (starts the development server)

5. Open developer tools in the browser window that pops up and take note of the URL template shown in the warning message:

This Flowgear Web App should run embedded in the Console. Use the following URL to debug: https://my.flowgear.net/r/sites/{siteId}/apps/debug/?debugUrl=https%3A%2F%2Flocalhost%3A44305%2F

6. Copy the URL provided in to a new browser tab and replace {siteId} with the ID of one of your Flowgear Sites.

7. When that URL is opened, you should see a Dashboard app showing utilisation metrics for the current Site.

Building your own App

We recommend building your own app by starting with the sample app but you can also start with a new react project.

If you're starting with a new project, first create a directory. Then run the following command to bootstrap a react app: npx create-react-app my-directory --typescript

and be sure to add the following line to the generated package.json file:
"homepage": "./"

To start with the sample application, clone it from https://github.com/Flowgear/flowgear-samples.

Note that only client-side code will be published so you are free to use a different IDE if desired.

Initializing the App

Open sample-app/src/index.js and add the following code before you instantiate the top-level React component:

Flowgear.Sdk.init();

Flowgear.Sdk.applyStylesheets();

Be sure to reference the SDK located at ./components/flowgearSdk by adding the following to the top of the file:

import { Flowgear } from './components/flowgearSdk';

This code initializes messaging between the App and the Console and then configures stylesheets so that the UI of your App is consistent with the Console.

Using the SDK

The SDK client library located at sample-app/src/components/flowgearSdk.tsx contains wrapper functions for all supported capabilities. The following functions are supported:

  • init() - called when your App initializes to configure the messaging interface with the Console

  • applyStylesheets() - pulls in stylesheet definitions so that the UI of your App is consistent with the Console

  • invoke() - provides API calls in to Flowgear. This API is used to call native API's (for example https://api.flowgear.net/users/{userId}/sites) as well as custom API's that have been published from workflows (for example https://yourcompany.flowgear.net/someendpoint). You do not need to add authentication information, the SDK will automatically add it based on the context of the current user

  • getContext() - returns information about the current Console context including the current siteId, pod number and theme (default or dark theme)

  • confirmModal() - displays a modal with a custom prompt that enables the user to confirm or cancel an action

  • getTextModal() - displays a modal with a custom prompt that enables the user to input text

  • setAlert() - displays a standard Flowgear alert as either informational, warning or error. The alert can be configured to auto-hide or require explicit dismissal

  • openUrl() - opens the specified URL in a new browser tab

Debugging the App

Launch your project, on load a message will be written to the browser Console Window (typically accessed by opening Developer Tools in the browser):

This Flowgear Web App should run embedded in the Console. Use the following URL to debug: https://my.flowgear.net/r/sites/{siteId}/apps/debug/?debugUrl=https%3A%2F%2Flocalhost%3A44305%2F

Copy the URL provided in to a new browser tab and replace {siteId} with the ID of one of your Flowgear Sites. The App will then be able to load and the SDK will be functional.

Publishing your App

1. Prepare your App for publishing by adding the file app.json in to the sample-app/public folder.

Below is a specimen of the expected content of the file:

{

  "ManifestVersion": 1,
  "Name": "SampleApp",
  "Version": "1.0.0.0",
  "DisplayName": "Sample App",
  "EmbedMode": "menu",
  "EmbedParameters": {
    "After": "workflows"
  }

}

  • ManifestVersion should be set to 1

  • Name should contain a camel-case internal name for the App that is unique across Flowgear. Consider applying a namespace to this - for example yourcompany.yourapp. As this name must be unique across all tenants, you will need to change the name of the Sample App before you'll be able to publish it

  • Version should be incremented each time the App is going to be published. It is not possible to re-publish the same version of an App

  • DisplayName will be presented as the name of the App in the front-end in both the Pane title area and in the menu (if the App is embedded into the menu)

  • EmbedMode indicates how the App should embed into the Console. Currently this property can be left blank (user must know the URL to the app in order to open it) or menu which indicates that the App will embed in to the left-hand menu.

  • EmbedParameters specifies parameters pertaining to the EmbedMode property. Where EmbedMode is set to menu, a parameter named After may be specified. The value on this parameter indicates which menu item the App icon should embed after

2. Add an SVG icon named icon.svg in to your publish root. This icon is used when the App is focused and also shown in the menu when the App is embedded in the menu.

3. Obtain the App publish assets by running the command: npm run build

4. Navigate to the publish location (the default location for the Sample App will be sample-app/build).

5. Zip the files in this location, then within Flowgear, click Settings and Apps from the left-hand menu.

6. Click + and choose the Flowgear Account you would like to publish the App through then upload the Zip file created earlier and click Submit.

7. Once the App has published it will show up in the Apps list. Open the App by clicking it in the list.

8. On the right-hand pane, select and add the Sites you would like the App to be published to. Switch to the Site or refresh your Console in order for the App to embed.

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