Http

Http Activity Properties

Property	Value	Required	Notes
Body	InArgument<String>	No	Represents data to be transferred in the HTTP request to the server.
DisplayName	String	No	Specify a name for the activity or accept the default.
Headers	InArgument<StringDictionary>	No	Represents the name/value pairs that are transferred in the request.
MediaType	InArgument<String>	Yes	The media type of the body of the request. (e.g., “application/json”). Media type is typically used with POST, PUT, PATCH methods/verbs.
Method	InArgument<String>	Yes	HTTP method that indicates the action to be performed for a given resource: GET, POST, PUT, HEAD, DELETE, PATCH, CONNECT, OPTIONS, TRACE
ResponseBody	OutArgument<String>	No	The response body returned from the server.
ResponseStatusCode	OutArgument<HttpStatusCode>	No	Represents the HTTP response status code issued by the server in response to the request (e.g., 200, 401, 500, etc.).
URI	InArgument<String>	Yes	The Universal Resource Identifier to which the request will be made (e.g., “https://www.host.com/resource”).

Examples

Invoke an Azure Logic App

The workflow example below is available on GitHub. Refer to the instructions at https://github.com/campusmanagement/workflow-samples/blob/master/README.md.

This example shows how the Http activity can be used to invoke an Azure logic app. The xaml file is available here: Cmc.Nexus.Crm.Entities.TaskEntity_SavingEvent_Sample - Azure Logic Apps.xaml.

1. The SerializeToJson activity serializes an input argument object named "entity" and produces the output string named "message".

   

2. The next activity is an Http activity. It:

   • Uses the serialized "message" string as input argument in the Body property.
   • Defines the input as MediaType = "application/json".
   • Invokes the "POST" method.
   • Creates the output argument named "responseBody".
   • Sends the output to URI = "https://logicAppUrl" using the POST method.

   

3. The If activity validates the output from the Http activity using the following Boolean condition:

   not string.IsNullOrEmpty(responseBody)

   The string.IsNullOrEmpty(responseBody) method checks whether the specified string (i.e., responseBody) is null or an empty string ("").

   

   • If the condition is met (i.e., the responseBody string is empty), the CreateValidationItem activity creates an error message.

     

   • If the condition is not met, the responseBody string is sent to the URI specified in the Http activity

Invoke an Azure Function

The workflow example below is available on GitHub. Refer to the instructions at https://github.com/campusmanagement/workflow-samples/blob/master/README.md.

This example shows how the Http activity can be used to invoke an Azure function. The xaml file is available here: Cmc.Nexus.Crm.Entities.TaskEntity_SavingEvent_Sample - Azure Functions.xaml.

1. The SerializeToJson activity serializes an input argument object named "entity" and produces the output string named "message".

   

2. The next activity is an Http activity. It:

   • Uses the serialized "message" string as input argument in the Body property.
   • Defines the input as MediaType = "application/json".
   • Invokes the "POST" method.
   • Creates the output argument named "responseBody".
   • Sends the output to URI = "https://azureFunctionUrl" using the POST method.

   

3. The If activity validates the output from the Http activity using the following Boolean condition:

   not string.IsNullOrEmpty(responseBody) AND responseBody <> """"""

   The string.IsNullOrEmpty(responseBody) method checks whether the specified string (i.e., responseBody) is null or an empty string ("").

   

   • If the condition is met (i.e., the responseBody string is empty), the CreateValidationItem activity creates an error message.

     

   • If the condition is not met, the responseBody string is sent to the URI specified in the Http activity

Http vs. SendToAzureServiceBus

To demonstrate the difference between the Http and SendToAzureServiceBus activities, we created a workflow that multiplies two numbers (24 x 365) and returns the result (8,760).

• The Http activity returns the result immediately to a workflow variable.

• The SendToAzureServiceBus activity sends the result to the service bus where it is processed by an application that is listening for messages. Then response is sent to the email address specified in the request.

  In more complex scenarios, the response from the service bus listener process could be a call back into another system –- or the service bus listener would forward the message to a 3rd party application to be posted to that system.

The workflow uses the following variables:

Http Activity

The Http activity:

• Uses the string assignments (nbr1 and nbr2) as input arguments in the Body property.
• Defines the input as MediaType = "application/json".
• Invokes the "POST" method.
• Creates the output argument named "httpResponseBody".
• Creates the output argument named "httpResponseStatus" whose value is checked in the If Condition.
• Sends the output to a Uri on an Azure web site that hosts an API.

The API multiplies the numbers 2 numbers in the request Body (nbr1 and nbr2) and returns the result.

 

SendToAzureServiceBus Activity

The SendToAzureServiceBus activity:

• Sends the string assignments (nbr1 and nbr2) and "emailTo" variable to the Azure Service Bus.
• Specifies the path for the Azure Service Bus as "mathqueue".
• Specifies the user's service name space and access key in Azure.

In Azure, the message is placed in the "mathqueue" and processed.

When the service bus request is processed, an email is sent to the user.