Table of Contents

maxLevel	3

What is the PEL?

The Pipeline Expression Language (PEL) or just PE (Pipeline Expression) is an expression language that can optionally be used inside a pipeline to do data mapping and to dynamically calculate, set and change values at processing time of the pipeline. This gives you a huge flexibility in your pipeline.

...

Output:

Code Block
Counter: 1

Operators

The PEL supports all common operators as also known for most programming languages. It is similar to the expressions in Microsoft Excel, although the syntax is slightly different and aligned a bit more with the traditional programming syntax.

Relational operators

Is equal (==)

Example 1

Code Block
pipeline: - log: message: "#{2 == 1}"

Output:

Code Block
false

Is not equal (!=)

Example 1

Code Block
pipeline: - log: message: "#{2 != 1}"

Output:

Code Block
true

Less than (<)

Example 1

Code Block
pipeline: - log: message: "#{1 < 5}"

Output:

Code Block
true

Example 2

Code Block
pipeline: - log: message: "#{0.5 < 1}"

Output:

Code Block
true

Less or equal than (<=)

Example 1

Code Block
pipeline: - log: message: "#{1 <= 5}"

Output:

Code Block
true

Greater than (>)

Example 1

Code Block
pipeline: - log: message: "#{1 > 5}"

Output:

Code Block
false

Greater or equal than (>=)

Example 1

Code Block
pipeline: - log: message: "#{5 >= 5}"

Output:

Code Block
true

Detect alphabetical order with <, >, <=, >=

Example 1

Code Block
pipeline: - log: message: "#{'Adam' < 'Zacharias'}"

Output:

Code Block
true

Regular expression matching (matches)

Example 1

Code Block
pipeline: - log: message: "#{'5.0067' matches '^-?\\d+(\\.\\d{2})?$'}"

Output:

Code Block
false

Logical operators

and

Example 1

Code Block
pipeline: - log: message: "#{true and false}"

Output:

Code Block
false

or

Example 1

Code Block
pipeline: - log: message: "#{true or false}"

Output:

Code Block
true

not (!)

Example 1

Code Block
pipeline: - log: message: "#{!true}"

Output:

Code Block
false

Mathematical operators

Addition and subtraction

Example 1 - Addition

Code Block
pipeline: - log: message: "#{1 + 1}"

Output:

Code Block
2

Example 2 - Subtraction

Code Block
pipeline: - log: message: "#{10 - 1}"

Output:

Code Block
9

Example 3 - Addition an subtraction

Code Block
pipeline: - log: message: "#{25 - 5 + 10}"

Output:

Code Block
30

Example 4 - String concatenation

Code Block
pipeline: - log: message: "#{'Hello ' + 'World!'}"

Output:

Code Block
Hello World!

Multiplication and division

Example 1 - Multiplication

Code Block
pipeline: - log: message: "#{3 * 5}"

Output:

Code Block
15

Example 2 - Negative multiplication

Code Block
pipeline: - log: message: "#{-1 * 5}"

Output:

Code Block
-5

Example 3 - Division

Code Block
pipeline: - log: message: "#{20 / 5}"

Output:

Code Block
4

Example 4 - Modulus

Code Block
pipeline: - log: message: "#{7 % 4}"

Output:

Code Block
3

Example 5 - Operator precedence

Code Block
pipeline: - log: message: "#{5 + 4 - 1 * 2}"

Output:

Code Block
7

Example 6 - Brackets

Code Block
pipeline: - log: message: "#{(5 + 4 - 1) * 2}"

Output:

Code Block
16

Assignment

Example 1

Code Block
pipeline: - set: value: "1" output: "#{vars.counter}" - log: message: "#{vars.counter}"

Output:

Code Block
1

Example 2

Code Block
vars: counter: 12 pipeline: - set: value: "#{vars.counter + 1}" output: "#{vars.counter}" - log: message: "#{vars.counter}"

Output:

Code Block
13

Working with lists and maps / dictionaries

Creating a new list

Example 1 - A new empty list

Code Block
vars: numbers: "#{{}}" pipeline: - log: message: "#{vars.numbers}"

Output:

Code Block
[]

Example 2 - A new list with default content

Code Block

language	yaml

vars:
  numbers: "#{{1, 2, 4}}"
pipeline:
  - log:
      message: "#{vars.numbers}"

Output:

Code Block
[1, 2, 4]

Example 3 - A new, nested list

Code Block

language	yaml

vars:
  scores: "#{{ {1, 3}, {5, 8} }}"
pipeline:
  - log:
      message: "#{vars.scores}"

...

Code Block
[[1, 3], [5, 8]]

Accessing lists and arrays

Example 1

Code Block

language	yaml

vars:
  numbers: "#{{1, 2, 4}}"
pipeline:
  - log:
      message: "#{vars.numbers[1]}"

Output:

Code Block
2

Creating a new map / dictionary

Example 1 - A new empty map

Code Block
vars: persons: "#{ {:} }" pipeline: - log: message: "#{vars.persons}"

Output:

Code Block
{}

Example 2 - A new map with default values

Code Block
vars: persons: "#{ {hanna:'burger', max:'hotdog', julie:'salad'} }" pipeline: - log: message: "#{vars.persons}"

...

Code Block
{hanna=burger, max=hotdog, julie=salad}

Example 3 - A new map with later binding

Code Block
vars: persons: "#{ {:} }" pipeline: - log: message: "#{vars.persons['Hanna'] = 23}"

Output:

Code Block
{Hanna=23}

Accessing maps/dictionaries

Example 1

Code Block
vars: persons: "#{ {hanna:'burger', max:'hotdog', julie:'salad'} }" pipeline: - log: message: "#{vars.persons['max']}"

Output:

Code Block
hotdog

Navigating objects

A PE can point to values inside an object (or nested data structure), like this JSON for example:

...

Code Block
#{person.hobbies[0]}

Example 1

In this more advanced example, there are different things to mention:

...

Code Block
Name: Bart Simpson Age: 12 Hobby: skateboard

Selection Expression

With the selection syntax you can select a subset of items from a given collection to be returned as new collection by specifying a selection expression.

...

Whereas collectionName is the variable name of the collection (can be an array, map, list, aso.) and selectionExpression is the expression which selects the items to be returned from the list.

Example 1

Lets assume we have a collection of entities like this stored in the body:

...

Code Block

vars: 
   data: '#{{
        {
          person: {
            name: "Bart Simpson",
            age: 12,
            hobbies: {
              "skateboard",
              "tv",
              "pranks"
            }
          }
        },
        {
          person: {
            name: "Maggie Simpson",
            age: 1,
            hobbies: {
              "drinking milk",
              "crawling",
              "crying"
            }
          }
        }
      }}'
pipeline:
  - log:
      message: "#{vars.data.?[person.name == 'Maggie Simpson']}"

Projection Expression

With the projection syntax you can select specific property values out from a collection of objects.

...

Whereas collectionName is the variable name of the collection (can be an array, map, list, aso.) and projectionExpression is the expression which selects the properties to be returned from each object in the list.

Example 1

Lets assume we have a collection of entities like this stored in the body:

...

Code Block

vars: 
   data: '#{{
        {
          person: {
            name: "Bart Simpson",
            age: 12,
            hobbies: {
              "skateboard",
              "tv",
              "pranks"
            }
          }
        },
        {
          person: {
            name: "Maggie Simpson",
            age: 1,
            hobbies: {
              "drinking milk",
              "crawling",
              "crying"
            }
          }
        }
      }}'
pipeline:
  - log:
      message: "#{vars.data.![person.name]}"

PEL Utils

Inside a PE you can use built-in Utils as helpers to simplify work.

A refecerence about available PEL Utils can be found in this section: PEL Utils Reference.

Example 1

Code Block
vars: cities: "Munich, Bratislava, New York" pipeline: - log: message: "#{@list.size(vars.cities)}"

Output:

Code Block
3

Example 2

Code Block
pipeline: - log: message: "#{@text.lang('Hallo, Herr Meier!')}"

...

Version	Old Version 1	New Version 2
Changes made by	PIPEFORCE	PIPEFORCE
Saved on	Oct 30, 2021	Oct 30, 2021

Page Comparison

Versions Compared

Key

What is the PEL?

Operators

Relational operators

Is equal (==)

Example 1

Is not equal (!=)

Example 1

Less than (<)

Example 1

Example 2

Less or equal than (<=)

Example 1

Greater than (>)

Example 1

Greater or equal than (>=)

Example 1

Detect alphabetical order with <, >, <=, >=

Example 1

Regular expression matching (matches)

Example 1

Logical operators

and

Example 1

or

Example 1

not (!)

Example 1

Mathematical operators

Addition and subtraction

Example 1 - Addition

Example 2 - Subtraction

Example 3 - Addition an subtraction

Example 4 - String concatenation

Multiplication and division

Example 1 - Multiplication

Example 2 - Negative multiplication

Example 3 - Division

Example 4 - Modulus

Example 5 - Operator precedence

Example 6 - Brackets

Assignment

Example 1

Example 2

Working with lists and maps / dictionaries

Creating a new list

Example 1 - A new empty list

Example 2 - A new list with default content

Example 3 - A new, nested list

Accessing lists and arrays

Example 1

Creating a new map / dictionary

Example 1 - A new empty map

Example 2 - A new map with default values

Example 3 - A new map with later binding

Accessing maps/dictionaries

Example 1

Navigating objects

Example 1

Selection Expression

Example 1

Projection Expression

Example 1

PEL Utils

Example 1

Example 2