Computed Field

The 'Name' property specifies the identifier for the computed field as it will appear in the search index and in search results. This name must be unique within the index and should follow code-friendly naming conventions (start with a letter or underscore, and use only letters, digits, and underscores).

• Choose a name that clearly describes the field's purpose or content, such as TotalAmount or NormalizedCustomerName.
• The name is used in search queries, filters, and when displaying results.
• Avoid spaces or special characters to ensure compatibility.

Can be one of the following types:

The 'Type Name' property determines the type of value produced by the computed field, such as System.String, System.Int32, or System.DateTime.

• Select a type that matches the expected output of your expression.
• The type affects how the field is indexed, queried, and displayed in search results.
• Use the type converter to choose from common types, or enter a fully qualified .NET type name if needed.

Example:
For a field that calculates a total, use System.Decimal or System.Double.

The 'Is Array' property determines if the computed field should return a single value or a collection (array) of values.

• Set to true if your expression generates multiple values (e.g., a list of tags or keywords).
• Set to false for single-value fields.
• The array type is based on the selected 'Type Name'.

Example:
To index all unique words in a document, set 'Is Array' to true and 'Type Name' to System.String.

The 'Description' property allows you to provide additional information about the purpose, logic, or intended use of the computed field.

• Use this property to document business rules, calculation logic, or any special considerations for the field.
• The description is displayed in the property grid and can help other users understand the field's role in the index.

Example:
This field calculates the total invoice amount by summing all line item amounts, including tax.

The 'Expression' property defines the logic that generates the value for the computed field. This expression can reference other fields, variables, or built-in functions, and is evaluated at index time for each document.

• Write expressions using Visual Basic .NET.
• Ensure the expression returns a value compatible with the selected 'Type Name' and 'Is Array' settings.
• Use the expression editor for syntax highlighting, code completion, and validation.

Examples:

• LineItems.Sum(Function(item) item.Amount) - Sums the 'Amount' field of all line items.
• CustomerName.ToUpperInvariant() - Normalizes the customer name for case-insensitive search.
• If(Total > 1000, "High Value", "Standard") - Flags high-value documents.

Test your expression to ensure it produces the expected results for all relevant documents.