Customizing start nodes

Start node is a special node of services that triggers the service execution and provides input parameters. The start node configuration can change based on the type of service you are creating.

Endpoint service start node

Endpoint services are triggered when a request is sent to the associated RESTful API endpoint. Endpoint start node receives all request parameters (body, headers, query string parameters, endpoint path identifiers) and additional system-generated data (e.g., session object if endpoint requires a session token and device information). It provides this data to the connected node input link points through is output link point. The following is the list of data that can be injected into an endpoint start node.

Name	Description	Example
ids	Endpoint path id parameters	If endpoint path is defined as /supplier/{supplierId} then this parameter keeps the value of supplierId
query	Endpoint path query string parameters	If endpoint path is defined as /supplier/{supplierId}?type=steel&country=US then this parameter keeps the value oftypeandcountry
headers	Request header parameters	If the RESTful API request has additional headers, then header data is provided through this request parameter
appParams	System generated parameter	If the app has a param named MIN_ORDER_QUANTITY then this parameter keeps the value of this parameter
client	System generated parameter	Provides device type (e.g., mobile, desktop) and device IP information
session	System generated parameter	If the session is marked as required for the endpoint, then this parameter provides the session data (e.g., session date, user id, token)
files	Named file uploads	If the request has file uploads named logoSmall and logoBlack then this parameter keeps the data of the uploaded files
filesList	List (array) of file upload	The same uploaded file information is provided as an array, without names, e.g., [logoSmall, logoBlack]
dbTransactions	List of database transactions	If the endpoint service will be using database transactions, then this parameter keeps the created database transactions
body	Request body data	If the endpoint has body data, then this parameter provides input data. Request body can be a single or an array of objects, or it can be a list of name-value pairs

The endpoint service start node has the following configuration parameters, aligned with a RESTFul API request.

• Request body - You can select to specify whether the service will have any request body input, have just an object or list of objects from a single mode, have multiple name-model pairs, or have a custom transient model object.
  • Single model - If you select a single model as a request body, you can either pass a single object or an array of specified model objects as input to your endpoint service. The count parameter specifies whether you pass a single object or an array (multiple)

• Multiple different models - If you select multiple different models, you provide a list of model object(s) that will be passed to your endpoint service as name-model pairs. In the example below, assuming that we have two models, one for products and the other for suppliers, we can pass a product and an array of suppliers as request body input parameter to our service using name-model pairs. "item" used as the name for a single "product" model object and "providers" used as the name for multiple (array) "supplier" model objects.

• Custom transient model - If you select the custom transient model option then you can define the model of the input object. This option is quite handy if you would like to define a specific model for the input of the endpoint and you do not need to define it in the "Models" view.

- **Query string parameters** - Query parameters are specified as name-value pairs. You can define multiple query parameters. For each query parameter, you need to specify its name and the value type and whether it is a single value or a list of values. For example, you can specify a single value integer query parameter named "pageSize" to pass pagination size to your service. Additionally, you can specify multiple text values named "tags" to pass a list of filter tags (e.g., \["tag1", "tag2", ...]) as input to your service.- **Request headers** - Requests headers configuration is very similar to query string parameters. The only difference is request headers are sent through the HTTP headers, whereas query string parameters are passed as a part of the endpoint URL. Headers are also specified as name-value pairs. You can define multiple headers. For each header you need to specify its name and the value type and whether it is a single value or a list of values. - **File uploads -** In your service request body, you can upload single or multiple files identified with key values.

• Database transactions - If you plan to have a database transaction in your service, you define all transactions in the start node and access them from database nodes that support transactions.

Messaging service start node

The configuration parameters of a messaging service start node are as follows:

• Message body - A messaging service processes the input message sent through the message queue. The message body is similar in structure to an endpoint service request body with multiple different models (please see above). You provide the list of model object(s) that will be passed to your messaging service as name-model pairs. In the message body, you can also pass looked up object reference field values.

• Database transactions - If you plan to have a database transaction in your service, you define all transactions in the start node and access them from database nodes that support transactions.

Task service start node

The configuration parameter of a task service start node is as follows:

• Database transactions - If you plan to have a database transaction in your service, you define all transactions in the start node and access them from database nodes that support transactions.