Variables in Apps

Use variables to store values between pages.

Note:

You can set a default value of the variable on page load by using the Set Value rule in the Loaded event of the page.

Apps supports creating variables of the following types:

• AppsFile - file objects specific for Apps, which handles files uploading or downloading.

  new AppsFile("https://imageURL.png")

• Array - arrays of primitive data types or complex objects. For example:

  • Array of strings : New String() {"Hello", "World"}
  • Array of AppsFile: New AppsFile() { new AppsFile("Url1"), new AppsFile("Url2")}

  • Array of entity type:

    new Customer() { 
    New Customer("1", "Baishali"), 
    New Customer("2", "Viswa"), 
    New Customer("3", "Evan") }

• ChoiceSet - stores the choice set data of an entity. For example:

  • GetChoiceSet("Team") - returns a ListSource with the choice set values.
  • GetChoiceSetValue("Team", 1) - returns the indicated choice set value.

• DataTable - a system data type used to store the value of a process Datatable output argument, or to create a custom Datatable, for example:

  BuildDataTable(
      New DataTable("TestDT"), 
      New DataColumn(){ New DataColumn("Name"), New DataColumn("Age")},
      New List(Of Object) From { 
          AddDataRow(New Object(){"Baishali", "30"}), 
          AddDataRow(New Object(){"Viswa", "33"}) 
      },
      True
  )

• Date - for example, New System.DateTime (1993, 5, 31, 12, 35, 0).
• DateOnly - a specific date, without time. For example, New System.DateOnly (2020, 04, 20).

• DateTimeOffset - a date and time, relative to UTC. This structure includes a DateTime value and an Offset property, that defines the difference between the current DateTimeOffset date and the Coordinated Universal Time (UTC). For example:

  new System.DateTimeOffset( new System.DateTime(2023, 5, 15, 7, 0, 0),
    new System.TimeSpan(-7, 0, 0) )
  // output 5/15/2023 7:00:00 AM - 07:00

• Decimal number - for example, 88.53.

• Double

• Guid - the unique identifier of an entity.

• Int16

• Int64

• List<T> - for example:

  • List of strings : New List(Of String) From {"string 1", "string 2", "string 3"}

  • List of ListPair (for dropdown controls):

    New List(Of Customer) From { 
    New Customer("1", "Baishali"), 
    New Customer("2", "Viswa"), 
    New Customer("3", "Evan") }

• ListSource - used to store the result of a entity query in a variable. You need to use the syntax ListSource(of <Entity_name>).

• Nullable - used to define a null value. By default, all reference types, such as String, are nullable, but all value types, such as Int32, are not.

  Note:

  By default, primitive data types, except String, are non-nullable. Use this variable type to set them to null. For example, if you create an app variable of type Nullable<Int32>, then you can set the value to "Nothing".

• Object - stores any type.

• Single - Used to store floating-point values that do not require the full data width of Double. The default value is 0.

• Text (String) - for example, "Hello world"

• True or false (Boolean)

• UInt16 - holds unsigned 16-bit (2-byte) integers ranging in value from 0 through 65,535.

• UInt32 - holds unsigned 32-bit (4-byte) integers ranging in value from 0 through 4,294,967,295.

• UInt64 - holds unsigned 64-bit (8-byte) integers ranging in value from 0 through 18,446,744,073,709,551,615.

• Whole number (Int32) - for example, 88