Expression Set

Below are various examples of default value expressions:

Default to a literal string value:
"None"

Default to a literal numeric value:
25.00

Default to the current date and time:
DateTime.Now

Default to the current date:
DateTime.Today

Default to the current user name:
Environment.UserName

Default to the current machine name:
Environment.MachineName

Default to the MIME type of the document:
Folder.NativeMimeType

Default to the name of the Content Type assigned to the document:
ContentTypeName

Default to the "Subject" metadata element of a PDF file:
DirectCast(Handler, PdfMimeTypeHandler).Subject

Default to the filename associated with a File System Link:
DirectCast(Link, FileSystemLink).Filename

Default to the filename associated with a File System Link without the extension:
IO.Path.GetFileNameWithoutExtension(DirectCast(Link,FileSystemLink).FilePath)

Default to the name of the 2nd directory level associated with a File System Link:
Link.GetPathSegment(1)

Default to the sender associated with a Mail Message:
DirectCast(Handler, MailMimeTypeHandler).From

Generate a unique identifier:
Guid.NewGuid

A Calculate Expression is a VB.Net code snippet which calculates the value for a field based on the value of other fields - similar to the way a formula defines a relationship between various cells in a spreadsheet. Depending on the value of the 'Calculate Mode' property, the expression can be used to validate the field or automatically populate its value.

The expression must produce a value compatible with the field's Value Type. If the field is a Decimal type, the expression should evaluate to a Decimal value. If the field is a DateTime type, the expression should evaluate to a DateTime value. If the expression produces an invalid value which cannot be converted to the field's type, the field will be set to an error state.

Simple Examples

LINQ Examples

Expressions may use LINQ syntax to access information in collections, such as tables and multi-instance sections.

Can be one of the following values:

This setting affects the validation performed by a calculate expression. If this property is set to 0, then the field value must exactly match the calculated value.

Sections, Tables, and Fields which are peers in the Data Model hierarchy may be referenced by name. A return value of True indicates that the value of the field is valid, and false indicates that the field value is invalid. Below are various examples of validate expressions:

Invoice Total must be greater than 0 and less than 100,000:
(Invoice_Total > 0) And (Invoice_Total < 100000)

Invoice Total must be greater than or equal the Subtotal:
Invoice_Total > Subtotal

Invoice Date cannot be older than 90 days:
DateTime.Now.Subtract(Invoice_Date).TotalDays <= 90

Invoice No cannot contain a tilde (~) character:
Not Invoice_No.Contains("~")

This expression should generate a string containing the error message. Below are some simple examples of validate messages.

Display a static message:

"Dates prior to 1901 are not allowed."

Generate a dynamic message using field data:

$"Cannot exceed Line Total of {Line_Total:c}."

See string interpolation for additional reading on string formatting.

If no message is specified, a default error message will be displayed.