Build Linear-Connected Apps in Mendix

Mendix is a high-productivity app platform that allows you to build and maintain both mobile and web applications at-scale. When paired with CData Connect AI, Mendix provides instant, cloud-to-cloud access to Linear data for applications. This article demonstrates how to connect to a CData Connect AI data source from within Mendix.

CData Connect AI provides a pure cloud-to-cloud interface for Linear, allowing you to import data from live Linear data in Mendix — without replicating the data to a natively supported database. As you build web and mobile applications from within Mendix, CData Connect AI pushes all supported SQL operations (filters, JOINs, etc.) directly to Linear, leveraging server-side processing to return the requested Linear data quickly.

Configure Linear Connectivity for Mendix

To work with Linear data from Mendix, we need to connect to Linear from Connect AI, provide user access to the connection, and create a Workspace for the Linear data.

Connect to Linear from Connect AI

CData Connect AI uses a straightforward, point-and-click interface to connect to data sources.

1. Log into Connect AI, click Sources, and then click Add Connection

2. Select "Linear" from the Add Connection panel

3. Enter the necessary authentication properties to connect to Linear.

   You can authenticate to Linear with a personal API key or with OAuth 2.0. The API key is the simplest option for connecting with your own Linear account.

   Authenticating with an API Key

   Set the following connection properties:

   • AuthScheme: Set this to APIKey.
   • APIKey: A Linear personal API key.

   To create a personal API key, log in to Linear, open Settings > Security & access > Personal API keys, select New API key, and create it. Copy the key immediately, because Linear shows it only once.

   Authenticating with OAuth

   OAuth requires a custom OAuth application registered in Linear (Settings > API > OAuth applications), which provides the OAuthClientId and OAuthClientSecret. Two flows are supported:

   • Authorization code: Set AuthScheme to OAuth, InitiateOAuth to GETANDREFRESH, and provide OAuthClientId, OAuthClientSecret, and the CallbackURL defined in your application (e.g., http://localhost:33333). The driver opens Linear in your browser so you can grant access.
   • Client credentials: Set AuthScheme to OAuthClient and provide OAuthClientId and OAuthClientSecret. This authenticates the application itself, with no browser interaction, and suits machine-to-machine integrations.

   By default, the driver requests the read,write scopes. The driver refreshes the access token automatically when it expires.

   
4. Click Save & Test
5. Navigate to the Permissions tab in the Add Linear Connection page and update the User-based permissions.

Add a Personal Access Token

When connecting to Connect AI through the REST API, the OData API, or the Virtual SQL Server, a Personal Access Token (PAT) is used to authenticate the connection to Connect AI. It is best practice to create a separate PAT for each service to maintain granularity of access.

1. Click on the Gear icon () at the top right of the Connect AI app to open the settings page.
2. On the Settings page, go to the Access Tokens section and click Create PAT.
3. Give the PAT a name and click Create.
4. The personal access token is only visible at creation, so be sure to copy it and store it securely for future use.

Configure Linear Endpoints for Mendix

After connecting to Linear, create a workspace for your desired table(s).

1. Navigate to the Workspaces page and click Add to create a new Workspace (or select an existing workspace).
2. Click Add to add new assets to the Workspace.
3. Select the Linear connection (e.g. Linear1) and click Next.
4. Select the table(s) you wish to work with and click Confirm.
5. Make note of the OData Service URL for your workspace, e.g. https://cloud.cdata.com/api/odata/{workspace_name}

With the connection, PAT, and Workspace configured, you are ready to connect to Linear data from Mendix.

Build a Linear-Connected App

Downloading the OData Metadata File

When creating a connection in Mendix, the connection flow requires a Data Source Contract File. Follow these steps to download the OData metadata file for CData Connect AI using curl, a command line tool:

1. Open a command-line window for your operating system. On Windows, open the start menu, type cmd, and press the Enter key to open a command prompt. On macOS and Linux, open a Terminal window.
2. To check if curl is installed on your system, type curl -help and press the enter key. If it is not installed, install it from the curl website.
3. Issue the following curl command, replacing USER with your CData Connect AI username and PAT with the PAT you generated above:

   curl -u USER:PAT https://cloud.cdata.com/api/odata/{workspace_name}/$metadata -o metadata.xml

4. Locate the metadata.xml file that the curl command created and move it to an accessible location.

Connecting to CData Connect AI in Mendix

Follow these steps to establish a connection from Mendix to CData Connect AI:

1. Login to Mendix and open the Data Hub page.

2. In the Register a Data Source section, select OData.

3. Upload the metadata.xml file from the steps above and click Next.

4. Enter your desired values for Data Source Name and Data Source Version. In the Data Source Relative Path field, enter /api/odata/{workspace_name} and click Next.

5. On the Application information page, click Register a new application.

6. Enter a name in Application Name and select a technical owner (by default, this is the user who is currently logged in).

7. Click Next. In the Environment Name field, enter a desired name (for example, CData Connect AI). In the Environment Location field, enter https://cloud.cdata.com and select the appropriate Environment Type (e.g. Production), depending on what is needed.

8. Click Done! to create your connection.

You can now use your connection in Mendix Studio Pro to easily create applications with access to live Linear data.

Get CData Connect AI

To get live data access to hundreds of SaaS, Big Data, and NoSQL sources directly from your cloud applications, try CData Connect AI today!