Creating your First REST API

When a request comes in:

1. The first branch accepts requests with any last name that appears in the REST request.
2. The second branch then checks to see if the last name in the request is "Jones". You configure this check (condition) in the Branch Mapping Settings for this branch. If the last name is "Jones" then the flow outputs the passenger details with the Class element automatically set to Business Class meaning that the passenger's seat has been booked in Business Class. You configure this action of automatically setting the Class element to BusinessClass for passengers with last name "Jones" in the Return activity for this branch.
3. If the last name received is not "Jones" the control is transferred to the first branch whose flow outputs the details of the request as received with the Class to Economy.

In this tutorial, we will use a simple JSON schema for the REST request that the service receives and the response that the service sends back. The following is the structure of our JSON schema used in this tutorial. This JSON message will be converted internally into a JSON schema:

{
  "Class" : "string",
  "Cost" : 0,
  "DepartureDate" : "2017-05-27",
  "DeparturePoint" : "string",
  "Destination" : "string",
  "FirstName" : "string",
  "Id" : 0,
  "LastName" : "string"
}

The high-level steps for creating and configuring the airlines flight reservation service REST app in this tutorial are as follows:

1. Create a New TIBCO Flogo^® App
2. Create a Flow in the App with a REST Trigger
3. Map Trigger Output to Flow Input. This is the bridge between the trigger and the flow where the trigger passes on the request data to the flow a flow input.
4. Map Flow Output to Trigger Reply. This is the bridge between the flow output and the response that the trigger sends back to the HTTP request it received. After the flow has finished executing, the output of the flow execution is passed back to the trigger by the Return activity. Hence, we map the flow output to the trigger reply. This mapping is done in the trigger configuration.
5. Add a Log Message Activity to the Flow and configure a message that the activity must log in the logs for the app as soon as it receives a request.
6. Add the First Branch and Configure It to accept any last name that appears in the REST request.
7. Add a Second Branch to Check for Last Name "Jones". If the last name of the passenger is "Jones", this branch is executed and the passenger is placed in Business Class.
8. Validate the App to make sure that there are no errors or warnings in any flows or activities.
9. Build the App
10. Test the App

Follow these steps to create a new app:

1. Open the Apps tab in TIBCO Cloud Integration - Flogo (PAYG).
2. Click Create/Import app.
3. By default, a Flogo app is named New_Flogo_App_<sequential-number> where the sequential-number is the next number of a new app being created. Click the default app name next to the Flogo app icon to make it editable. Edit the app name to FlightApp and click anywhere outside the name to persist your change.

Follow these steps to create a flow:

1. Click Create. The Flow option is selected by default in the Add triggers and flows dialog.
2. Enter FlightBookings in the Name text box and optionally a description for the flow in the Description text box and click Create.

   

3. Click Start with a trigger.

   

4. Click the Receive HTTP Message card in the Triggers catalog.

   

5. In the Configure trigger: ReceiveHTTPMessage dialog, do the following:

   

   1. Select POST as the Method.
   2. Enter /FlightBookings in the Resource path text box.
   3. Enter the following schema that an incoming request must adhere to in the Enter a JSON Schema or an example of your JSON message box:
      Important: Make sure to use straight quotes when entering the schema elements and values.

      {
        "Class" : "string",
        "Cost" : 0,
        "DepartureDate" : "2017-05-27",
        "DeparturePoint" : "string",
        "Destination" : "string",
        "FirstName" : "string",
        "Id" : 0,
        "LastName" : "string"
      }

   4. Click Continue.
6. Select Copy Schema when prompted as shown below.

   

   The schema that you entered when creating the trigger automatically gets copied to the following locations when the trigger is added:

   • Flow input in the Input Settings tab of the Flow Inputs & Outputs accordian tab.
   • It is displayed in a tree format in the Map to Flow Inputs tab of the trigger. This allows you to map the elements from the trigger output to flow input elements, such that the trigger output feeds into the flow input.
   • The Reply Settings tab of the trigger, if the trigger has a reply. In the next step, you map the flow output schema elements to the trigger reply. By doing so, you send the output from the flow back to the trigger such that it becomes the trigger reply.

   A new flow is created attached to a REST trigger.

   Your flow should look similar to the following:

   

7. Collapse the Flow Inputs & Outputs accordian tab by clicking the left-facing arrow above the tab name in the blue vertical bar.

To do so, follow these steps:

1. Click the REST trigger on the top left corner of the flow to open its configuration dialog.

   

2. Click the Map to Flow Inputs tab.
3. Click headers under Flow Input, then click $trigger > headers under Trigger Output to map the headers.
4. Click body under Flow Input, then click $trigger > body to map the elements under body.
5. Click Save.

To map the flow output to the trigger reply, do the following:

1. Click the Map from Flow Outputs tab.
   1. Click the code under Trigger Reply to open the mapper.
   2. Click $flow > code under Flow Output.
   3. Click data under Trigger Reply.
   4. Click $flow > data under Flow Output.
   5. Click Save to save your changes.
   6. Click x to close the dialog.

      The flow should look like the following:

      

Follow these steps to add a LogMessage activity:

1. Add a new LogMessage activity from the General tab and configure it. To do so,
   1. Hover your mouse cursor to the right of the Flow Inputs & Outputs tab and click .

      

   2. In the Add Activity dialog, click General, then click Log Message.
   3. Configure the LogMessage activity with a message to log when it receives an incoming request from the ReceiveHTTPMessage trigger. To do so:
      1. Click the Input tab.
      2. Click message to open the mapper to the right. You will now configure a message to be logged by the LogMessage activity when the flow receives the input from the request that the trigger received and passed on to the flow.
      3. To configure the message, expand the string category under Functions and click concat(str, str2) to add this function to the message text box.
      4. Select str in the and replace it by entering "We have received a message from " (include the quotes too).
      5. Replace str2 with the last name of the passenger who booked the flight. The last name of the passenger is passed on from the trigger to the flow. We had mapped this trigger output to flow input in step 3 above. Hence it is now available for mapping under $flow in Upstream Output.
         To map the LastName do the following:

         1. Select str2.
         2. Expand $flow > body under Upstream Output.
         3. Click LastName.
         4. Click Save to save your changes.

         

   4. Click the x on the upper right side of the LogMessage box to close it. The LogMessage activity is added to the right of the Flow Inputs & Outputs tab.

Do the following to add a branch and configure its condition to accept any last name:

1. Hover your mouse cursor over the LogMessage activity and click .

   

   The branch gets added with the Add Activity dialog open.

2. Click the x on the upper right corner of the Add Activity dialog to close it.
3. Add a Return activity to the branch. To do so,
   1. Hover your mouse cursor to the end of the branch and click the () icon.
   2. Scroll to the Default category and click it.
   3. Click the Return card to add the activity.
   4. Click the x to close the configuration dialog. You must now configure the Return activity with a condition to read the last name of the passenger.
4. Hover your mouse cursor to the end of the branch until you see a button with three dots placed horizontally.

   

   Click the button to expose the following options:

   

   Click (). The Branch Mapping Settings dialog opens.

   Select the Success with condition branch condition.

   1. Click condition to open the mapper on the right.
   2. Configure the branch condition with a regular expression that accepts all last names.
      1. Expand the string category under Functions and click regex(pattern, str) to add this function to the condition text box.
      2. Replace pattern in the expression by manually entering ".*" (include the quotes too).
      3. Replace str in the function with the last name that is mapped from the flow output under Upstream Output. To do so, expand $flow > body and click on LastName. Your condition

         

      4. Click Save.
5. Configure the Return activity for the branch to output the flow results if this branch executes (when the passenger's last name is anything but Jones). To configure the activity, follow these steps:
   1. Click on the Return activity to open its configuration.
   2. Expand data under Flow Outputs.
   3. Click code to open the mapper and enter 200 in the text box.
   4. Expand data under Flow Outputs.
   5. Click Class and enter "Economy".

      

   6. Expand $flow > body under Upstream Output.
   7. One by one, map all remaining elements of the flow outputs under data (Cost, DepartureDate, DeparturePoint, Destination, FirstName, and LastName) except ID, by first clicking on them under data and then clicking on the corresponding element under body. Do not map id.
   8. Click id under data to configure it.
   9. Expand the number category under Functions and click random().
   10. Enter 999999 as an input parameter to the random() function.

       

   11. Click Save.
   12. Click x to close the dialog.

The second branch you add from the LogMessage activity checks the LastName element in the incoming request to see if it is "Jones". If the passenger's last name is "Jones", the passenger's seat is automatically upgraded to Business Class.

To add a second branch from the LogMessage activity, follow these steps:

1. Hover your mouse cursor over the LogMessage activity and click .

   

   The branch gets added with the Add Activity dialog open.

2. Click the x on the upper right corner of the Add Activity dialog to close it.
3. Add a Return activity. To do so,
   1. Hover your mouse cursor to the end of the branch and click the () icon.
   2. Scroll to the Default category and click it.
   3. Click the Return card to add the activity.
   4. Click the x to close the configuration dialog. You must now configure this branch with a condition to read the last name of the passenger and check to see if it is "Jones".
4. Hover your mouse cursor to the end of the branch until you see a button with three dots placed horizontally.

   Click the button to expose the following options:

   

   Click (). The Branch Mapping Settings dialog opens.

   Select the Success with condition branch condition.

5. Configure the condition for the branch to check if the last name ends with "Jones".
   Note: The string for the last name is case sensitive. So, "Jones" is considered different from "jones".
   1. Click condition to open the mapper.
   2. Expand $flow > body under Upstream Output.
   3. Expand the string function group and click endsWith(str, substr).
   4. Replace str by manually typing "Jones" (include the quotes).
      Note: The string for the last name is case sensitive. So, "Jones" is viewed as different from "jones".
   5. Select substr, then click LastName under body. This replaces the str with the last name extracted from the output of the ReceiveHTTPMessage trigger.

      

   6. Click Save.
6. Configure the Return1 activity to send the flow results back to the trigger if the second branch executes (it will execute when the passenger's last name is Jones.).
   1. Click Return1 to open its configuration dialog.
   2. Expand data under Flow Outputs.
   3. Click code and enter 200 in its text box.
   4. Click Class under data and enter "Business Class" (include the surrounding double quotes).

      

   5. Expand $flow > body under Upstream Output.
   6. Map all remaining elements under data (Cost, DepartureDate, DeparturePoint, Destination, FirstName, and LastName) except id, by clicking on them one at a time and then clicking on the corresponding element under body. Do not map id.
   7. Click Id under data to configure it.
   8. Expand the number function and click random().
   9. Enter 999999 as the input to the random() function.

      

   10. Click Save.
   11. Click x to close the dialog.