Work with Expressions

Use expressions to evaluate and perform calculations on data stored in data objects, process pre-defined variables, process input, process output, and task outcomes.

Use expressions to change values passed to and from a sequence flow. You can create expressions when configuring data associations, and when configuring properties for these activities:

  • Human tasks: Use an expression to dynamically determine the task title, summary, due date, and assignees.

  • Conditional sequence flows: Use an expression to define its condition.

  • Conditions and markers: Use an expression to define activation conditions and markers.

To create an expression for a flow element, click Expression mode icon from the flow element’s properties field. This enables the expression mode and you can use the inline expression builder which gives auto-complete options for you to create and build your expression.

To create an expression while configuring data associations, enter the expression directly in the input or output fields of the data association editor. You can use the inline expression builder which gives auto-complete options for you to create and build your expression.

The following is an example image of the inline expression builder being used while configuring data association.

Description of exp-build.png follows
Description of the illustration exp-build.png
  • Create expressions with data objects, operators, and functions. As soon as you put the cursor in the expression field, you get a list of suggested objects using which you can build the expression.
  • As you choose the object, related suggestions for the next level are displayed below the field. The suggestions are context sensitive. For example, suggestions displayed for a Title field will be different from that of a Due Date field.
  • Use Ctrl + Space to get more tabs and suggestions. A search field also displays that you can use to search data objects under the various tabs such as Process or Activity.
  • The type that is expected to be entered into the expression field is auto-suggested at the top right of the field.
  • If an expression is invalid, for example, if you type a number in a string field, an error message indicating the details of the error is displayed.
  • If the configured expression is too long, you can expand the field by using Ctrl + Enter keys.

About Simple Expressions

Simple expressions are defined using a basic expression language and support. You can use these operators to write expressions and conditions to define your process flow. Generally these expressions perform their calculations based on the data objects in your business process. You can write expressions and conditions using the value of the data objects, but you can’t explicitly modify the value within the data object.

Here are some examples of expressions using operators:

  • totalAmount - discount

  • activationCount > 3

  • unitsSold <= 1200

Operator Precedence

Operator precedence defines the order in which the compiler evaluates operators. You can change operator precedence in an expression by using parentheses. In Oracle Cloud Infrastructure Process Automation, the operator precedence is:

  • Addition, Subtraction

  • Multiplication, Division, Remainder

  • Plus, Minus

  • Less than, Greater than, Less than or equal to, Greater than or equal to

  • Equals, Not equals

  • Not

  • Conditional And

  • Conditional Or

The following sections lists Operators and Functions per type.

Unary

Operator Name Description
+ Plus Has no effect on the value of the numeric operand. Use it to explicitly indicate that a certain value is positive.
- Minus Negates an arithmetic expression.
! Not Logical complement operator. Negates the value of a Boolean expression.

Equality and Relational

Operator Name Description
= or == Equal to Returns true if the first operand is equal to the second operand
!= Not equal to Returns true if the first operand isn't equal to the second operand
> Greater than Returns true if the first operand is greater than the second operand
>= Greater than or equal to Returns true if the first operand is greater than or equal to the second operand
< Less than Returns true if the first operand is less than the second operand
<= Less than or equal to Returns true if the first operand is less than or equal to the second operand

Conditional

Operator Name Description
and Conditional And Returns true if both operands evaluate to true
or Conditional Or Returns true if either operand evaluates to true

String

Function/Operator Description Usage Expression Usage Result
+ String concatenation “pine” + “apple” “pineapple”
== Equals “apples” == “apples” true
!= Not equals “apples” != “oranges” true
> Greater than “word” > “work” false
>= Greater than or equals “work” >= “work” true
< Less than “word” < “work” true
<= Less than or equals “work” <= “work” true
contains Returns true if the first argument string contains the second argument string; otherwise returns false “caramel”.contains(“ram”) true
endsWith Returns true if the first argument string ends with the second argument string; otherwise returns false “immutable”.endsWith(“table”) true
length Returns the number of characters in a string “house”.length() 5
lowerCase Returns a string with all the characters in the argument converted to lower-case representation “Example”.lowerCase() “example”
startsWith Returns true if the first argument string starts with the second argument string, otherwise returns false “caramel”.startsWith(“car”) true
substring Returns the substring of the first argument starting at the position specified in the second argument and continuing to the end of the string “care”.substring(2) “are”
substring Returns the substring of the first argument starting at the position specified in the second argument with length specified in the third argument “care”.substring(1,3) “car”
upperCase Returns a string with all the characters in the argument converted to upper-case representation “Example”.upperCase() "EXAMPLE"
replaceAll Replaces each substring of this string that matches the given pattern with the given replacement. "care".replaceAll("e", "t") "cart"
indexOf Returns the index of the first occurrence of the specified substring, or -1 if there is no such occurrence. "care".indexOf("a") 2

Numeric

The following table includes operators for both Integer and Number.

Operator Description Usage Expression Usage Result
+ Addition 2 + 8 10
- Subtraction 7 – 4 3
* Multiplication 3 * 4 12
/ Division 3 / 2 1.5
% Remainder 3 % 2 1
== Equals 12 == 13 false
!= Not equals 12 != 13 true
> Greater than 15 > 16 false
>= Greater than or equals 15 >= 15 true
< Less than 12 < 10 false
<= Less than or equals 12 <= 12 true
abs Returns the absolute value of a number abs(- 6) 6

In addition to the above, the following specific operators are also available for Number.

Operator Description Usage Expression Usage Result
floor Returns the largest (closest to positive infinity) number that isn't greater than the argument and is an integer floor(5.60) 5
ceil Returns the smallest (closest to negative infinity) number that isn't less than the argument and is an integer ceil(5.60) 6
round Returns the number that is closest to the argument and is an integer round(5.60) 6

Date and Time

Date and Time types include Date, Time, and DateTime. All of them have the following operators.

Operator Description
+ Addition (valid only when the second argument is a duration)
- Subtraction (valid only when the second argument is a duration)
== Equals
!= Not equals
> Greater than
>= Greater than or equals
< Less than
<= Less than or equals
format Returns the formatted string of date-time using the provided format picture

In addition, Date, Time, and DateTime have specific operators as listed under each of them.

Date

Operator Description
year Returns a number representing the year component of the date-time argument.
month Returns a number representing the month component of the date-time argument.
day Returns a number representing the day component of the date-time argument.

Time

Operator Description
hours Returns a number between 0 and 23, both inclusive, representing the hours component of the date-time argument
minutes Returns a number between 0 and 59, both inclusive, representing the minutes component of the date-time argument.
seconds Returns a number between 0 and 59, both inclusive, representing the seconds component of the date-time argument.

DateTime

Operator Description
year Returns a number representing the year component of the date-time argument.
month Returns a number representing the month component of the date-time argument.
day Returns a number representing the day component of the date-time argument.
hours Returns a number between 0 and 23, both inclusive, representing the hours component of the date-time argument.
minutes Returns a number between 0 and 59, both inclusive, representing the minutes component of the date-time argument.
seconds Returns a number between 0 and 59, both inclusive, representing the seconds component of the date-time argument.
timezone Returns an interval value, representing the time offset from UTC.
toTimezone

Returns the date-time expressed in the time offset corresponding to the timezone ID provided.

You have the following options for specifying a timezone ID:

  • Provide a fixed offset from UTC/Greenwich, such as "-07:00".

    For example:

    • dateTimeDO.toTimezone("-07:00") returns 2002-11-30T17:20:00-07:00 when dateTimeDO is 2002-12-01T01:20:00+01:00

  • Specify a geographical region, which is an area where a specific set of rules for finding the offset from UTC/Greenwich apply. A geographical region is usually represented in the format "{area}/{city}", such as "Europe/Amsterdam" or "America/New_York".

    For example:

    • dateTimeDO.toTimezone("America/Los_Angeles") returns 2002-11-30T16:20:00-08:00 when dateTimeDO is 2002-12-01T01:20:00+01:00

Note:

You must include double quotation marks around the timezone ID value.

For more information about timezone IDs, see Class ZoneId in the Java Platform documentation.

Boolean

Operator Description Usage Expression Usage Result
== Equals true == true true
!= Not Equals true != false true
and Conditional — And true and false false
or Conditional — Or true or false true
not Logical complement operator, inverts the value of a Boolean expression. not true false

Duration

Operator Description
== Equals
!= Not equals
> Greater than
>= Greater than or equals
< Less than
<= Less than or equals

Array

Operator Description
[ ] Access a particular element into the array
== Equals
!= Not equals
length Returns the number of elements contained within the array

Other

Operator Description
== Equals
!= Not equals

Special Constants

Constants Description
null Null value
true Logical true
false Logical false
‘now’ Current dateTime

Casting

In some cases, it could be desirable to bypass the type validation in order to assign types that aren't necessarily compatible. For example, you may want to assign an 'int' value to a 'string' one and in order to do that you can use the conversion operation like this:

<conversionTypeName> ( <valueToConvert> )

where the 'conversionTypeName' is the type you want to see as the value.

Here are some conversion examples:

  • string(myIntDO)

  • int(myStringDO)

  • duration(mystringDO)

Note:

You can only cast to primitive types, so the 'conversionTypeName' will only accept those that have a valid value.

Assigning two values that are incompatible will result in a runtime error.

Additional Functions

Identity Service

Function Description Available Usage Function Prototype Usage Example
getUserId Returns a string containing the id for a specific user name. Process wide IdentityService.getUserId(<userName:string>): string IdentityService.getUserId("wfaulkner")
getUserIds Returns a string containing the ids (separated by commas) for a list of user names (also separated by commas). Process wide IdentityService.getUserIds(<userNames:string>): string IdentityService.getUserIds("wfaulkner, jstein")

Get or Else

Function Description Available Usage Function Prototype Usage Example
boolean Request an object property along with a backup value. The backup value is used if the first argument corresponds to a missing node or an uninitialized value. This function set is useful while dealing with an untrustworthy data source, where initialization isn’t guaranteed. Process wide GetOrElse.boolean(<expression:boolean>,<fallbackValue:boolean>): boolean GetOrElse.boolean(myDO.boolAtt, true)
string Process wide GetOrElse.string(<expression:string>,<fallbackValue:string>): string GetOrElse.string(myDO.stringAtt, "User")
number Process wide GetOrElse.number(<expression:number>,<fallbackValue:number>): number GetOrElse.number(myDO.numberAtt, 25.3d)
integer Process wide GetOrElse.integer(<expression:integer>,<fallbackValue:integer>): integer GetOrElse.integer(myDO.integerAtt, 12)