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RESTAPICLIENT Workflow Application

Overview

The RESTAPICLIENT workflow application allows you to call REST API endpoints to exchange information with other applications through HTTP requests, and can be used to build integrations with extendable applications (such as Azure Services and Slack).

It also allows you to call a REST API endpoint using application/json or application/x-www-form-urlencoded payloads. RESTAPICLIENT will then receive and process the response from the external API by mapping the response content with defined OUT parameters.

How it works

  • The RESTAPICLIENT application requires the APP_URL parameter, which corresponds to the REST API endpoint.

  • The default request payload content type (APP_REQUEST_CONTENT_TYPE) is application/json. application/x-www-form-urlencoded is also supported.

  • The default HTTP request method (APP_METHOD) is GET. Other request methods (POST, PUT, DELETE, etc.) are also supported.

  • In case of error, when the APP_RESPONSE_IGNORE_ERROR OUT parameter is defined and has Y as its value, the error will be ignored and defined OUT parameters (APP_RESPONSE_STATUS or APP_RESPONSE_CONTENT) will be mapped. Otherwise, an exception will be thrown.

  • Since the application parameters are case sensitive, parameters must use the API’s accepted notation.

  • The default request timeout is 30,000 milliseconds (30 seconds); this default value can be modified by setting the RestApiClientRequestTimeout parameter value in the web.config file. The request timeout can also be defined in the APP_TIMEOUT IN parameter; the maximum timeout is 3,600,000 milliseconds (1 hour).

    ✏️ Note: This timeout value must be less than the IIS request timeout value.

  • The HTTP request headers can be defined with the APP_HEADER_xxx parameters, where xxx is the header field name. For more information, see the Header parameters section.

  • The request payload can be defined in the APP_REQUEST_CONTENT_FILE or APP_REQUEST_CONTENT IN parameters. When both parameters are defined, the APP_REQUEST_CONTENT_FILE parameter has priority. For more information on these parameters, see the Request payload section.

  • The response from the REST API can be mapped to the APP_RESPONSE_CONTENT_FILE or APP_RESPONSE_CONTENT OUT parameters. Both parameters can be defined at the same time. For more information on these parameters, see the Response payload section.

  • Besides the optional parameters listed below, you can also add additional custom IN and OUT parameters to send and receive custom user-defined data to and from the external API. For more information on and examples of these custom IN and OUT parameters, see the Request payload and Response payload sections.

  • The application supports the JSONPath query language (see https://github.com/json-path/JsonPath), which allows extraction of specific data from a JSON response (similar to XPath expressions in XML). For information on how to use this with the application along with examples, see the Response payload section.

  • Application logs are available and can be specified by setting the RestApiClientLogLevel parameter value in the web.config file to 0 to disable logging (default), 2 for simple logs, or 3 for debug logs.

  • The default maximum response length is 4194304 characters (4 MB); this default value can be modified by setting the RestApiClientMaxResponseLength parameter value in the web.config file.

  • Automatic deletion of temporary files can be disabled by setting the RestApiClientEnableFilesCleanUp parameter value to N in the web.config file; the default value is Y.

Required parameter

Optional parameters

General

APP_URL optional parameters

📌 Example

The parameters defined above will generate the following URL in APP_URL:

https://management.azure.com/subscriptions/457a2a46-7a7f-4afa-940d-8779e1425fa8/resourceGroups/dev-group-advantys/providers/Microsoft.EventGrid/topics/dev-topic

Header parameters

📌 Example

The parameters defined above will generate two headers in the request payload:

Authorization: Bearer AbCdEf123456
location: canadaeast

Authorization parameters

The application also supports some predefined authorization header parameters in order to avoid adding these HTTP header parameters with the APP_HEADER_xxx parameter name.

  • Only one authorization header can be defined, otherwise an exception is thrown.

  • APP_AUTH_BEARER_TOKEN is equivalent to defining the header parameter APP_HEADER_Authorization.

Request payload

There are two different ways to prepare the request payload. The first way is when you have access to the whole request payload (see Set the whole request payload via a parameter below); the second way is by building the JSON or URL encoded payload via IN parameters (see URL encoded request payload and JSON request payload below).

Set the whole request payload via a parameter

The following parameters can be used when you have access to the whole request payload, or the request content type is neither application/json nor application/x-www-form-urlencoded. You can set this request payload in a file/text data or directly in the text value.

  • APP_REQUEST_CONTENT_FILE has priority over APP_REQUEST_CONTENT.

  • APP_REQUEST_CONTENT has priority over IN parameters used to build a JSON or an URL encoded payload.

URL encoded request payload

The following examples show how to build a request payload with application/x-www-form-urlencoded as content type.

Standard URL encoded request payload

The following parameters are used to build a standard URL encoded request payload:

The parameters defined above will generate the following request payload:

param1=value1&param2=value2

JSON request payload encoded into a key name

The following parameters are used to build a JSON payload encoded into a key name:

The parameters defined above will generate the following request payload:

payload: { param1: "value1", "param2": "value2" }

The APP_REQUEST_CONTENT_PAYLOAD_NAME parameter is only supported with the application/x-www-form-urlencoded request content type.

JSON request payload

The following examples show how to build a request payload with application/json as content type.

Standard JSON request payload

The following parameters are used to build a simple JSON request payload:

The parameters defined above will generate the following request payload:

{
    "person": {
        "address": {
            "street": "160 Guy Street",
            "zipcode": "J4G 1U4"
        },
        "age": 30,
        "name": "John"
    }
}

If you want to convert this JSON into an array, you have to set the APP_REQUEST_CONTENT_IS_ARRAY parameter value to Y.

Setting the APP_REQUEST_CONTENT_IS_ARRAY parameter to Y will generate the following request payload:

[{
    "person": {
        "address": {
            "street": "160 Guy Street",
            "zipcode": "J4G 1U4"
        },
        "age": 30,
        "name": "John"
    }
}]

To see how to build more complex JSON, see Setting a JSON array into a JSON property and Setting a JSON object/array into a JSON property using the __JSON suffix parameter sections below.

Setting a JSON array into a JSON property

To set an array into a JSON property, you have to define the property path (e.g. person.spokenlanguages) followed by the __X suffix, where X is the array index number.

The following parameters are used to set a JSON array into a JSON property:

The parameters defined above will generate the following request payload:

{
    "person": {
        "spokenlanguages": ["french", "english", "chinese"]
    }
}

If you want to set a JSON array of JSON objects (e.g. "spokenlanguages": [{"spokenlanguage":"french"}, {"spokenlanguage":"english"}]) into a JSON property, see the next section.

  • The array parameters will be ordered depending on their index number.

  • Index numbers have no limit (e.g. person.spokenlanguages__9999).

  • A correct index sequence is not mandatory (e.g. person.spokenlanguages__90, person.spokenlanguages__30). The __30 parameter value will be the first array parameter, and __90 the second one.

  • An exception will be thrown if there is more than one JSON property specified in the IN parameters (e.g. person.spokenlanguages and person.spokenlanguages__0).

  • The __X suffix uses two underscore characters.

  • The parameter value can only be a text value.

Setting a JSON object/array into a JSON property using the __JSON suffix parameter

To set a JSON object/array into a JSON property, you have to define the property path (e.g. person.children) followed by the __JSON suffix with the JSON object/array as the parameter value.

The following parameters are used to set a JSON object/array into a JSON property:

The parameters defined above will generate the following request payload:

{
    "person": {
        "children": [{
            "name": "child 1"
        }, {
            "name": "child 2"
        }]
    }
}

  • An exception will be thrown if there is more than one JSON property specified in the IN parameters. (e.g. person.children and person.children__JSON).

  • The __JSON suffix uses two underscore characters.

Response payload

The application supports OUT parameters to be mapped with the HTTP response:

Mapping a JSON response payload with OUT parameters

The application also supports additional custom OUT parameters to map simple JSON response payloads.

📌 Example

JSON response payload:

{
    "person": {
        "address": {
            "street": "160 Guy Street",
            "zipcode": "J4G 1U4"
        },
        "age": 30,
        "name": "John"
    }
}

The following parameters allow you to map the response payload into different process data:

For mapping complex JSON, see the next section.

Mapping a JSON response payload with OUT parameters using JSONPath query language

The application supports the JSONPath query language (similar to XPath expressions in XML). This language allows you to retrieve specific data from a JSON. For more details regarding the JSONPath syntax, see https://github.com/json-path/JsonPath.

📌 Example

JSON response payload:

{
    "person": {
      "name": "Elizabeth",
      "children": [
        {
          "name": "Charles",
          "age": 30,
          "children": [
            {
              "name": "Nathalie",
              "children": [
                {
                  "name": "George",
                  "age": 8
                },
                {
                  "name": "Charlotte",
                  "age": 10
                },
                {
                  "name": "Jefferson",
                  "age": 7
                }
              ]
            },
            {
              "name": "Harry"
            }
          ]
        },
        {
          "name": "Bob",
          "age": 20,
          "children": [
            {
              "name": "John"
            },
            {
              "name": "Mark"
            }
          ]
        }
      ]
    }
}

For example, here we want to get the names of Charles's grandsons who are older than seven years old, and we also want these names separated by a | (using the APP_JSONPATH_DELIMITER IN parameter). To get this information, the following parameters must be defined:

  • In the PARAM1__JSONPATH parameter name, the PARAM1 name is not relevant but it must be followed by the __JSONPATH suffix (two underscores are used in the suffix).

  • The default value of APP_JSONPATH_DELIMITER is a comma (,) when this parameter is not defined.

Usage example with Azure REST API to obtain an OAuth 2.0 access token and then create an Event Grid topic

This example shows how to obtain an access token and use it to create an Event Grid topic. This can be done by creating a process with two actions having RESTAPICLIENT as application. The workflow below illustrates this example:

The next sections describe the parameters that must be declared for each action.

GET_TOKEN action: Obtaining an OAuth 2.0 access token

The following parameters are needed to get an access token to use the Azure Resource management API. This token will be stored in the access_token OUT parameter and will be used when creating an Event Grid topic in the next section.

The parameters defined above will generate the following request payload:

POST https://login.microsoftonline.com/a6e70c61-fabd-4885-89f7-97121e92db7f/oauth2/token HTTP/1.1
Host: login.microsoftonline.com
Content-Type: application/x-www-form-urlencoded

grant_type=client_credentials&client_id=b7e29e2f-6e2b-4375-9684-8151431d4ca6&client_secret=lxy/IwKyTedHUWMeeUtyCtu7/YUy0rNGoY3NNWXXotI=&resource=https://management.core.windows.net/

Here's the response from the Azure API:

{  
   "token_type":"Bearer",
   "expires_in":"3600",
   "ext_expires_in":"3600",
   "expires_on":"1555951493",
   "not_before":"1555947593",
   "resource":"https://management.core.windows.net/",
   "access_token":"eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1d..."
}

The access_token OUT parameter is mapped with the access_token JSON property.

For more details about how to get an access token to use the Azure Resource API, see https://docs.microsoft.com/en-us/azure/active-directory/develop/v1-oauth2-client-creds-grant-flow#request-an-access-token.

CREATE_TOPIC action: Creating an Event Grid topic

The following parameters are needed to create an Event Grid topic using the Azure Resource management API.

The parameters defined above will generate the following request payload:

PUT https://management.azure.com/subscriptions/235765d9-5d62-43f4-a730-2ed71a3f8adb/resourceGroups/dev-group-advantys/providers/Microsoft.EventGrid/topics/new-topic-example?api-version=2018-09-15-preview
Host: management.azure.com
Content-Type: application/json
Authorization: Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsIng1d...
location: canadaeast

Here's the response from the Azure API:

{  
   "properties":{  
      "provisioningState":"Creating",
      "endpoint":null
   },
   "location":"canadaeast",
   "tags":null,
   "id":"/subscriptions/994e2fc0-937d-4110-b355-e7473acef822/resourceGroups/dev-evt-grid/providers/Microsoft.EventGrid/topics/test-from-wfg",
   "name":"test-from-wfg",
   "type":"Microsoft.EventGrid/topics"
}

For more information about how to create an Event Grid topic and the Azure REST API, see https://docs.microsoft.com/en-us/rest/api/eventgrid/topics/createorupdate.

Enabling SSL/TLS

In case of a Could not create SSL/TLS secure channel error, strong encryption must be enabled by executing the following code in PowerShell:

Set-ItemProperty -Path 'HKLM:\SOFTWARE\Wow6432Node\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord

Set-ItemProperty -Path 'HKLM:\SOFTWARE\Microsoft\.NetFramework\v4.0.30319' -Name 'SchUseStrongCrypto' -Value '1' -Type DWord

Restart your IIS server after executing the commands.

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