Sequence expressions are sophisticated and flexible tools for retrieving the information you need in workflows. An expression is a .NET compiled method, and is always typed. You can use Sequence expressions for the following actions.
- Create complex business rules
- Easily define default values for fields on forms
- Generate dynamic workflow messages
- User workflow and activity data and metadata while integrating with other systems
- Integrate with SQL queries
- Obtain runtime data (including HTTP request, and a user's information)
Sequence expressions are composed of building blocks, which are typed objects, whose properties, methods, and functions are accessible.
Expression Markup Types
There are several ways to write expressions in a form's markup, each with a different function.
|Expression Markup Type||Description|
|The expression is calculated during the build of the control tree, so it might execute twice, but will always work.|
|The expression is executed only as part of the control's binding. Some controls have different binding order, so execution might fail.|
|The expression is calculated on each page render, but cannot be sued as a control property.|