Warning!
This is a legacy document. The features described below are only usable within the classic-generation environment.
Currently, Betty Blocks offers faster and more advanced options that are available in next-gen. Before you start working on some new features in your application, consider doing it using the next-gen version. Good luck!
Expression properties are properties that can handle logic. Their value can change depending on how the expression is evaluated. You can use the property Type when creating properties for a model to determine how the output for an expression is formatted.
You can create an expression that, for example, concatenates separate records for providing a single record. You can specify that the First Name and Last Name in a model are combined to create a Full Name record.
You use the Type field when creating properties to assign a property as an expression. The following expression Types are available:
Checkbox expression
date time expression
Minutes expression
Minutes expression
Number expression
Number with decimal expression
Price expression
Text expression (multi-line)
Text expression (single line)
The following example explains how you can create an expression for concatenating separate properties in a model. Separate properties are used to form the details for a full address property.
Adding expression properties to a model
In the following example, a property expression is added to a model that concatenates separate records for forming a full address record:
1. Open the data model module and select the model. In the following example, the Address (A) model is selected. |
2. Select the New property button to open the New Property pane (B). Select the Property Type (C) required. For this expression, a Text (single line) expression (C) is required. |
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3. Specify the Name for the property. As shown in the example, the name Full Address is applied. This name and the property type are now also reflected in name details for the pane (A). |
4. Press the Save button to save the details for assigning this property as an expression. The saved property is now visible in the list of properties for the model. Once saved, you can now apply the expression in the Dynamic Value field (B). |
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Specify the expression (B) required for combining the individual records as shown in the example below. In this example, the address, zipcode and city details are to be concatenated into a single property, Full Address. Note: You can insert variables using the variable selector (C). When you select a model, the records for the model are displayed and you can select (D) and insert (E) the records in the expression. |
4. Press the Save button again to save the details you have specified. |
5. When you click on the property, the expression details are updated as shown (A). |
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Please refer to the Expression Reference for more information.
Note: If a change is applied to an expression, the application automatically starts to recalculate the affected record when you press Save. Please ensure that you only use complex expression where required when working with large databases.