Expression Grids

The Expression Grid is a convenient rules format designed specifically for organising a sequence of expressions. Prior to its introduction Rulesets such as Workflow, Script or Decision Table were often used for the same function, but were less suitable than a purposefully designed format. Just like other Rulesets, the Expression Grid accepts parameters and outputs a result.

Expression Grid Rule Format

Like all Common Knowledge rule formats, the Expresson Grid seamlessly integrates with Common Knowledge Designer and the Common Knowledge SDK and can be easily combined with other business rule formats to create powerful solutions to complex business rule problems.


Common Knowledge Expression Grids provide a range of capabilities that allow you to implement procedural logic to complement your declarative business rules:

Interactive Designer Visual, interactive designer provides an intuitive tabular format for representing procedural logic
Interactive Execution Standalone execution and validation of Expression Grids entirely within Common Knowledge Designer
Explanations Add explanations in the form of Reason Strings to any expression entry in an Expression Grid
Documentation Add custom information to each expression which will be included in auto-generated documentation


The Common Knowledge Expression Grid rule format incorporates an ever-growing set of features that assist you during the design, authoring, execution and testing of business rules procedural logic. Features include:

Nested Rules Embed execution of any other ruleset within Expression Grid expressions
Complex Expressions Specify complex expressions in an Expression Grid to perform a range of operations including invoking library functions and executing other rulesets
Interactive Debugger Interactively debug your Expression Grids using stack tracing and expression evaluation
Multiple Expressions Define an arbitrary number of complex expressions to be performed sequentially
Nested Rules Embed execution of any other ruleset within Expression Grid expressions
Expression Activation Colour-highlighting of performed expressions as Expression Grids are executed
Cell Formatting Change font and font size for best display of expressions
Summary Collapsible Summary column allows descriptive text to be associated with each expression
Parameters and Return Values Pass parameters directly to Expression Grids and have Expression Grids return a result