Var tagging element

Use the Var tagging element to define a variable that stores a value for reuse within a document template. To use a Var tagging element, you need to set the variable name and then define its value by binding it to a data field or expression. Once defined, you can reference the variable in Power Fx expressions of other tagging elements throughout your template.

Prerequisites

Define variable value

To use a Var tagging element to define a variable holding a reusable value, follow these steps:

  1. Select the Variable tagging element in your template or in the Elements pane to view its properties.
  2. In the Var Properties pane, enter a descriptive Name for the variable that you will use to reference it later.
  3. Locate the Value property and choose the value button to open the value binding panel. Under Source, select the data section that contains your data. Under Path, navigate the data structure tree and select the data field, or enter a Power Fx expression that calculates the value to store.
  4. Choose the OK button (OK icon) to confirm the binding.

Elements pane showing a Var tagging element selected with Var Properties displaying Name and Value properties. The Value binding panel shows MainData as Source with a data structure tree for selecting the field to store.

Reuse variable in template

Templates are processed from left to right and top to bottom. After you define a variable, you can use it anywhere later in the template by referencing it from the Variables container in Power Fx expressions or other tagging elements.

To use a variable in an expression:

  1. Select the tagging element in the Elements Tree pane.

  2. Select the Value property to open the Power Fx Editor.

  3. Type a Power Fx formula that returns the value you need. For example, below is a Power Fx expression used in a Field tagging element within a Group tagging element that calculates the percentage of group total in total amount and uses previously defined variable TotalAmountInEuro.

    First(                  //Take first and only result from summarized table
    Summarize(
        GroupItems,     //summarize group items collection
        SelectProduct,  //summarize by Select Product field
    Sum(                //Aggregation function 
        ThisGroup,      //Source of values to sum up
        Amount.Amount) As 'GroupAmount' //Source field to sum up and project as 'GroupAmount' so it can be reused further
    )
).GroupAmount           //Use 'GroupAmount' from first result of summarized table
/                       //Divide 
Variables.TotalAmountInEuro * 100 //Divide by TotalAmountInEuros variable and multiply by 100 to get percentage

  4. Choose the OK button to confirm the binding.

  5. Review results in Live Preview pane.

Elements pane showing a Field tagging element bound to a variable. The Value binding panel displays Power Fy Editor as Source with the variable name visible in the Power Fx expression.

TIP

Use Variable tagging elements to calculate values once and reuse them multiple times, such as storing a calculated tax amount that appears in different sections of the document.

Apply visual formatting

You can specify visual formatting rules on the Var tagging element to control the visual appearance of related content in the generated document in a dynamic, data-driven manner. For detailed steps, see Apply visual formatting to tagging elements.

Next steps