Using yeeflow predefined functions in expression editor

Functions are are predefined formulas that can be used to perform simple or complex data calculations and logic validation etc.

Functions are predefined formulas that perform calculations by using specific values, called arguments, in a particular order, or structure. A expression support multiple predefined functions. A function support multiple functions between it, called nested functions.


Function Structure

The structure of a function begins with the function name , followed by an opening parenthesis, the arguments for the function separated by commas, and a closing parenthesis.

When you select any function name, you will see the instruction of how to use this function .


① Function Name

Yeeflow offer the available functions in listed based on your scenarios. 

② Argument(s) 

Arguments, or called parameters,  can be numbers, strings, datetimes, logical values such as TRUE or FALSE, arrays, lookup references, or any applicable expressions. The argument you designate must produce a valid value for that argument. Arguments can also be constants, formulas, or other functions.

③ Formula Tooltip

A tooltip will appears as you select this function. 

Nested Functions

In certain cases, you may need to use a function as one of the arguments of another function. For example, the following formula uses a nested isNullOrEmpty function as an argument to return the value. The isNullOrEmpty is nested within the iif function.  


Please Note:  When a nested function is used as an argument, the nested function must return the same type of value that the argument uses. For example, if the argument returns a TRUE or FALSE value, the nested function must return a TRUE or FALSE value. If the function doesn't, it displays an error value.

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Functions by Category

Functions are categorized by their functionality. Click a category header to quick browse its functions. 

Based on scenarios, Yeeflow offers different functions under categories. 

  • String Functions

String functions perform various character manipulations. They operate on character strings. A string expression evaluates to a sequence of characters or text.

Function Description Syntax Applied


Returns the number of characters in a text string or a numeric.

len(<check_expression>)  All


Searches an expression for another expression and returns its starting position if found.

strIndex(<expressionToFind>, <expressionToSearch>[, <start_location>])



Replacing first occurrence of a specified string value with another string value.




Creates a new string starting from a fixed number of characters into the original string. subString(<expression>,<start>,<length>)  All



Converts text to lowercase.

lower(<expression>)  All


Converts text to uppercase. upper(<expression>)  All
regExpTest Executes a search for a match between a regular expression and a specified string. Returns true or false. regExpTest(<regular expression>, <target>)  All
JSONParse Parses a JSON string, constructing the JavaScript value or object described by the string. JSONParse (<string>)

Forms Variables & Rules & Conditions 

JSONStringfy Converts a JavaScript object or value to a JSON string. JSONStringfy (<object>) Forms Variables & Rules & Conditions 
UniqueID Generates an unique id  UniqueID() Forms Variables & Rules & Conditions 

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  • Logical Functions

Logical functions can create expressions that convert values from one to another. 

Function Description Syntax Applied


Evaluates each WHEN condition and if satisfied, assigns the value in the corresponding THEN expression.

If none of the WHEN conditions are satisfied, it assigns the default value specified in the ELSE expression. If no ELSE expression is specified, the system automatically adds an ELSE NULL.

iif(<logical expression condition>, <then>, <else>)




Returns True if the specified String object is NULL or an empty string; otherwise, False is returned. isNullOrEmpty(<check_expression>) All


Changes false to true, or true to false. not(<parameter>) Forms Variables & Rules & Conditions 


Determines if an expression is ture.

The value of the expression is false in the following cases: null, empty string, string 'false', string of 'False', boolean false, otherwise is true

isTrue(<parameter>) Forms Variables & Rules & Conditions 
isFalse Determines if an expression is false. isFalse(<parameter>) Forms Variables & Rules & Conditions 

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  • Date Functions

Date functions conduct the data of DATE and DATETIME based on a calendar year.

Function Description Syntax Applied
datePicker Select the date and time. datePicker (<selected date>)  All
dateAdd Add or subtract the specified time interval from the date. dateAdd (<date>, <type>, <added value>) All
datePart Specifies the date of the specified date part datePart (<original date>, <type>) All
dateDiff Specifies the number of time intervals between two dates. If date 1 refers to a later point in time than date 2, the dateDiff function returns a negative number. dateDiff (<date 1>, <date 2>, <type>, <precise>) All
now Returns the current date and time. now () All

Format the current date and time:

year: YYYY
month: MM
day: DD
hours: HH
minutes: mm
seconds: ss

dateFormat (<date>, <format>) All

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  • Mathematical Functions

Mathematical functions perform mathematical operations on the data of NUMBER.

Function Description Syntax Applied
round Rounds a value to the nearest integer or to the specified number of fractional digits. round(<number expression>, [<digits>]) All

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  • Other Functions - Advanced functions

The other functions contain some advanced functions as:

  • Lookup functions, such as "listLookup"
  • System reference functions, such as "getUserAttr"
  • Statistical functions, such as "arrayConcat”
  • Engineer Functions. such as "getAttr"

It returns the values from your lookup source, system data, or some complex variables.  

Function Description Syntax Applied
getUserAttr Retrieves user attribute. Attributes will be separated by comma if user expression is an array. getUserAttr(<user expression>, <attribute>, [<default value>]) All
 getOrgAttr  Retrieves organization attribute. Attributes will be separated by comma if organization expression is an array. getOrgAttr(<organization expression>, <attribute>, [<default value>])  All
 getLocAttr  Retrieves location attribute. Attributes will be separated by comma if location expression is an array. getLocAttr(<location expression>, <attribute>, [<default value>]) All
arrIndex Locates the position of a value in array, return -1 if not exist. arrIndex(<array expression>, <value expression>) All
arrayConcat Returns a new array that contains the elements of each of the given sequence of two arrays. arrayConcat (<arr1>, <arr2>) All
listLookup Gets field value from data list. listLookup(<contentList>, <filter>, <field>, <defaultValue>) Forms Variables & Rules & Conditions 
positionLookup Finds user(s) by position. positionLookup (<position>, <type>, <result>, [<expr>]) Forms Variables & Rules & Conditions 
getAttr Returns the attribute value form an object by given. getAttr (<object>, <attribute>) Forms Variables & Rules & Conditions 

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