Build REST-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 Cloud, Mendix provides instant, cloud-to-cloud access to REST data for applications. This article demonstrates how to connect to a CData Connect Cloud data source from within Mendix.

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

Configure REST Connectivity for Mendix

Connectivity to REST from Mendix is made possible through CData Connect Cloud. To work with REST data from Mendix, we start by creating and configuring a REST connection.

1. Log into Connect Cloud, click Connections and click Add Connection

2. Select "REST" from the Add Connection panel

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

   See the Getting Started chapter in the data provider documentation to authenticate to your data source: The data provider models REST APIs as bidirectional database tables and XML/JSON files as read-only views (local files, files stored on popular cloud services, and FTP servers). The major authentication schemes are supported, including HTTP Basic, Digest, NTLM, OAuth, and FTP. See the Getting Started chapter in the data provider documentation for authentication guides.

   After setting the URI and providing any authentication values, set Format to "XML" or "JSON" and set DataModel to more closely match the data representation to the structure of your data.

   The DataModel property is the controlling property over how your data is represented into tables and toggles the following basic configurations.

   • Document (default): Model a top-level, document view of your REST data. The data provider returns nested elements as aggregates of data.
   • FlattenedDocuments: Implicitly join nested documents and their parents into a single table.
   • Relational: Return individual, related tables from hierarchical data. The tables contain a primary key and a foreign key that links to the parent document.

   See the Modeling REST Data chapter for more information on configuring the relational representation. You will also find the sample data used in the following examples. The data includes entries for people, the cars they own, and various maintenance services performed on those cars.

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

Configure REST Endpoints for Mendix

After connecting to REST, create a workspace and virtual dataset for your desired table(s).

1. Navigate to the Virtual Datasets 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 REST connection (e.g. REST1) 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 and Workspace configured, you are ready to connect to REST data from Mendix.

Build a REST-Connected App

With the Workspace added to Connect Cloud, you can build an app in Mendix with live access to REST data.

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 Cloud 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 Cloud 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 Cloud in Mendix

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

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 Cloud). 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 REST data.

Get CData Connect Cloud

To get live data access to 100+ SaaS, Big Data, and NoSQL sources directly from your cloud applications, try CData Connect Cloud today!