Understand Expression Editor

Easily grasp the Expression Editor in Yeeflow for efficient workflow customization. Enhance automation and streamline processes effortlessly

Updated over a week ago

The expression editor supports a variety of math, string, form expressions, and logical functions.

The Expression Editor is a powerful tool that allows you to edit various expressions in form controls or workflow actions.

  • Overview of expression elements

Yeeflow has different elements of the expression editor based on various scenarios. You may use the expression editor when you are intending to:

  • Various views-based scenarios

    • Create a rule or condition on a control

    • Execute a calculation control

    • Conduct a flow condition

    • Set a task title and assignee

Overview of Expression Elements

Yeeflow offers five expression elements that you can use in the Expression Editor.

  1. Values

  2. Expressions

  3. Functions

  4. Operators

① Values

You use Values to make outcome return, or to process logical calculations. It provides a simple value of a number (a) or a text input(b); also it also supports "true/false/[empty]"(c) per some logic values, such as a Boolean control of Switch that you may use in your form.




Return the logical value TRUE(YES), or determine if a value is TRUE(YES).


Return the logical value FALSE(NO), or determine if a value is FALSE(NO).


Return the value as a null or determine if a value is null.

② Expressions

You use Expressions to conduct logical rules and processing based on associated values or information. Yeeflow offers most of related expressions in workflow and applications and there are some different items based on both of them.

  • Workflow Related


Form Designer

Workflow Task

(differ based on Action Palette)

Flow Condition

Workflow Variables

(list all form controls)

Instance Context

Static Variables

(application and task status)



Task Context


Current Task Context


(task palette only)



(Task Outcomes)


(system data)


(system data)

(system data)

  • Application(Data List) Related

Please note: List workflow includes all workflow items as mentioned above.



List Form

Workflow Task


Flow Condition

List Fields

List Context

Temp Variables



(system data)

③ Functions

A function is a processor or relation that associates over two sets, and which associates every item of the first set, to exactly one item of the second set. A expression support multiple predefined functions.

You use Functions to create expressions that convert values. Yeeflow offers five types of functions by now.

④ Operators

Operators are used to specify comparisons between expressions. Yeeflow offers various types of operators. You use Operators to perform a logical conjunction between expression(s).

Various views-based scenarios

Base on the use of scenarios, Yeeflow offers different views and available elements in Expression Editor.

Ⅰ. Create a rule or condition on a control

You will be directed to expression editor when you're intending to create a rule/condition for a field control:

  • Dynamic Display Rules

When you set a dynamic display rule, It behaves differently based on specific conditions and rules. You will have full elements to define its Rules.

  • Custom Validation

When you set a custom error message that will display under any field (bound control) when specified conditions become true. You will have full elements to define its Rules.

  • Actions

When you set actions that should be taken on events that meet your designated rule criteria. You will have full elements to define its Conditions and Values.

Ⅱ. Execute a calculation control

A calculation can be a simple value of some number or text words or a logic display value that you use expression elements to conduct operations.

When you add a calculation, you will have full elements to define a form variable, and you will have limited elements to define a list field.

Ⅲ. Conduct a flow condition

You can add some condition(s) on the flow direction. Then you will be directed to Condition Editor.

The Expression Editor in this section is different. It consists of three parts:

① Expressions only of Expression Editor

② Corresponding Properties that Expression related

③ Auto-corresponding Operators based on left properties

Please Note: Yeeflow does not offer predefined Functions in flow conditions.

Ⅳ. Set a task title and assignee

Yeeflow offers you a custom Task Title that is associated with Expression. It allows you to add any available expression as a part of your task title.

Yeeflow also offers an Expression

to get your task assignee(s). It allows you to add any available expression as this task assignee(s).

Please Note: Yeeflow does not offer the predefined Functions in task assignments.

Did this answer your question?