Creating an array node in a document instance

A document instance that represents an array of objects can store multiple inputs from processes and connectors in the array.  In such a document instance, you can insert an array node at a given index or append it at the end. The node value can be a simple data type or a complex object. You can also remove a node from the given index. 

Adding or removing an array element returns an updated document instance. Therefore, you must map this action to some document instance. Ideally, you must map the adding and deleting action to a document instance that you have supplied as input.

Example

A user wants to update his home address on an online shopping portal. He also wants to add his office address in his profile, on the same portal. He goes to his profile, updates the existing address, and adds his new office address. 

Before you begin

Ensure that you have created a document instance with the following JSON:

For more information, see Creating a document instance.

To add an array node

1. Log in to  BMC Helix Innovation Studio.
2. To add an array element to a process, from the Workspace tab, navigate to the application for which you want to add an array node. 
3. In the Process designer, create a new process or navigate to the process in which you want to add the array element.
4. In Process designer, from the Palette, drag the Add Array Element To Document element onto the canvas.

5. In the Element Properties pane, enter the properties for the Add Array Element To Document element, as described in the following table:

   Property	Description
   GENERAL
   Label	Enter a suitable name for the element.
   Description	Enter details about the element.
   INPUT MAP
   Document Definition Name	Select the document definition that you want to use for this process.
   Document Instance	Document instance is a required input that you can capture from a process variable or other inputs.
   Node Name	Enter the node name of the array element.
   Value	Enter the value to be added to the array element.
   Index	(Optional) Specify the index at which you want to add the value in the array. If you enter an invalid input such as a negative value or a value more than the array size, the input is ignored and the value is appended at the end of the array.
   Replace	(Optional) Select this option if you want to replace the element at the specified index. When replace is selected (True), the new element replaces the old element. When the Replace option is not selected (False), the new element is inserted at the given index.
   MULTI INSTANCE LOOP
   Loop Type	Select Parallel or Sequential from the list. For information about Multi instance loop, see Creating process steps or activities.
   GEOMETRY
   Source	Select the document definition that you want to use for this process.

6. Click Save. 

To replace an array node

1. Log in to BMC Helix Innovation Studio. 
2. From the Workspace tab, navigate to the application for which you want to create a process to add an array element. 

3. In the Process designer, create a new process or navigate to the process in which you want to replace the array element.

4. In Process designer, from the Palette, drag the Add Array Element To Document element onto the canvas.

5. In the Element Properties pane, enter the properties for the Add Array Element To Document element, as described in the following table:

   Property	Description
   GENERAL
   Label	Enter a suitable name for the element.
   Description	Enter details about the element.
   INPUT MAP
   Document Definition Name	Select the document definition that you want to use for this process.
   Document Instance	Document instance is a required input that you can capture from a process variable or other inputs.
   Node Name	Enter the node name of the array element.
   Value	Enter the value to be added in the array element.
   Index	(Optional) Specify the index at which you want to add the value in the array. If you enter an invalid input such as a negative value or a value more than the array size, the input is ignored and the value is appended at the end of the array.
   Replace	Select this option if you want to replace the element at the specified index. The new element replaces the old element.
   MULTI INSTANCE LOOP
   Loop Type	Select Parallel or Sequential from the list. For information about Multi instance loop, see Creating process steps or activities.
   GEOMETRY
   Source	Select the document definition that you want to use for this process.

6. Click Save. 

To remove an array node

1. Log in to BMC Helix Innovation Studio. 
2. From the Workspace tab, navigate to the application for which you want to create a process to remove an array element. 

3. In the Process designer, create a new process or navigate to the process from which you want to remove the array element.

4. In Process designer, from the Palette, drag the Remove Array Element To Document element onto the canvas.

5. In the Element Properties pane, enter the properties for the Remove Array Element From Document element, as described in the following table:

   Property	Description
   GENERAL
   Label	Enter a suitable name for the element.
   Description	Enter details about the element.
   INPUT MAP
   Document Definition Name	Select the document definition that you want to use for this process.
   Document Instance	Document instance is a required input that can be captured from a process variable or other inputs.
   Node Name	Enter the node name of the array element.
   Index	Specify the index at which you want to remove the value in the array. If you enter an invalid input such as a negative value or value more than the array size, then the input is ignored.

6. Click Save.

Related topics

Defining a document schema

Creating a document instance