By the end of this chapter you will understand what a Calculate action is and how to use them, and you will have created three Calculate Actionflows in your application.

What is a Calculate Action?

The  Calculate action manipulates and processes data. Calculate nodes have their own attributes, which can reference incoming data via expressions, using one or more of the 135+ Functions available in PhixFlow.

Creating Calculate Actions

1. Click and drag the  Calculate icon from the toolbar onto the canvas
2. Enter a name for the Calculate action, then select Create Action
3. In the Calculate Action  Properties on the right, click the  icon in the Output Attributes section to add new attributes

Example Uses

Calculate Actions can be used for: 

• Inserting static text strings, e.g. when inserting a new record set a value of "New" in a status field
• Calculating values using Functions, e.g. Calculating the amount of VAT on a customer invoice  
• Performing lookups against a View action node or lookup connection point, e.g. counting records in a grid or retrieving details of all students on a course

Worked Examples

Here's a worked example using the School Data (available from the Learning Centre). 

Use a Calculate Action to Add Static Text

Earlier in this course we created an Actionflow that opens a blank input form for adding new courses to the School Courses grid. In this example we will enhance that Actionflow by adding the static text "New Course" to the blank input form.

1. Open the Course Management screen where the Actionflow will be initiated from
2. Right-click on the  button on the School Courses grid and choose  Display Actionflow
3. Click and drag the  Calculate icon from the toolbar onto the canvas
4. Enter a name for the Calculate Action:
   1. Name: Course Header
   2. Select Create Action 
5. The  Properties tab for the Calculate Action will open on the right
   1. If the  Properties tab is not open, click the Calculate Action node on the canvas 
6. In the Output Attributes section, click the  icon
7. Enter the following details for the new Output Attribute:
   1. Name: NewCourse
   2. Type: choose String

   3. Expression: 

      "Create New Course"

   4. Then  Apply and Close
8. Drag and drop the Course Header Calculate Action onto the connector between the input node and the Open Course Form Action
   1. 
9. Right-click on the connector between the Course Header Calculate Action and the Open Course Form Open Screen Action and choose  Open Mappings
10. On the Mappings window, drag the NewCourse attribute onto the Heading attribute to create the mapping
    1. Press Save
    2. 
11. Close the Actionflow to return to the Course Management screen
12.  Lock the screen and press the  button to see the Actionflow in action
    1. We can see that the Actionflow is working because it displays the string, New Course, in place of the original heading on the input form 

Use a Calculate Action to Perform a Function 

In this example, we will modify the Save Actionflow we created in an earlier chapter to perform the function, toUpper, which will format the course name into upper case. This example uses data for the input.

Setup the Input 

1. On the Course Management screen click the  or  button to open the Course Form
2. Right-click on the  button and select  Display Actionflow
3. Click and drag the  Calculate icon from the toolbar onto the canvas
4. Enter a name for the Calculate Action:
   1. Name: UppercaseName
   2. Select Create Action
5. Right-click on the input connection point under Connections and choose  Configure Mappings
6. On the Mappings window, drag the attribute, Name, from the left (Course Form) into the Drag and Drop space on the right (input connection point) 
   1. Select Save
7. On the canvas, drag the UppercaseName Calculate Action node onto the in connector between the  input node and the SaveCourse node and drop it when the  icon appears
8. Right-click on the in connector between the  input node and the  Calculate and select  Open Mappings
9. On the Mappings window, drag the Name attribute from the left to the right (calculate action)

   1. We only need to map the Name attribute here because it is used within the Calculate Action.

      The CourseID attribute will pass through the Calculate Action and can be used later on in the Actionflow.

   2. Select Save

Setup the Calculate Action 

1. Select the Calculate Action, UppercaseName, to open its Properties
2. In the Output Attributes section, click  to create a new attribute:
   1. Name: UpperName
   2. Type: choose String

   3. Expression:

      toUpper(in.Name)

3. Right-click on the in connector between the  Calculate node and the  Save and select  Open Mappings
4. On the Mappings window, drag the attribute, UpperName, from the Calculate Action (left) onto the Name attribute on the Save Action (right)
   1. Press Save
5. Close the Actionflow to return to the Course Form
6. Ensure the screen is  Locked, then add or edit the course details and press the  button to see the Actionflow in action
   1. You can see that the Actionflow is working because the Name for the course you just added/edited is now in capital letters on the School Courses grid