Expressions

Example: setting variables

Will return the result of a^2 + a^3.

Example: temporarily deactivate filter

Will always return true

Example: Extracting the unit

Will return "microns"

Example: Extracting the value

Will return 1

Example: Unit conversion

Will return "0.001 mm"

Supported units

px, pixels, pixel, nm, µm, microns, micron, mm, cm, dm, m, km, inch, in, foot, ft, yard, yd, ng, µg, mg, g, kg, t, Da, oz, lb, ns, µs, ms, s, min, h, d

Creating and combining arrays

Arrays are created via the ARRAY function

Arrays can also be added together:

, which would result in the output [1.0,5.0,8.0,1.0,2.0,3.0].

Extracting values

To extract an element from an array, use the @/[] operator or GET_ITEM/GET_ITEM_OR_DEFAULT:

all return 1.

Checking for item existence

The IN/CONTAINS operators can be used to check if an item is contained within an array.

Example: applying a function per array element

Results in [1.0,2.23606797749979,2.8284271247461903]. The ${ ... } operator is syntactic sugar to avoid having to manually escape more complex functions and can in this case be replaced with "SQRT(value)"

Creating maps

Maps can be created using the MAP() function that receives a list of arrays with two items (key and value). For better readability, we recommend to use the PAIR(key, value) function or the key: value operator.

All return a map {"a":1.0,"b":2.0}

Checking for key existence

Similar to Python, the IN operator checks the key set of the map:

Extracting values

To extract a value from a map, use the @/[] operator or GET_ITEM/GET_ITEM_OR_DEFAULT:

Parsing JSON

Use the PARSE_JSON method to convert JSON data into a map/boolean/array/number:

Creating JSON

Use the TO_JSON method to convert an object into JSON:

If-else

Use the IF_ELSE function to return the second or the third parameter depending on the first parameter.

will return "Universe works as expected".

If-else (lazy)

If you know that one of the IF_ELSE branches will yield an error, you can use IF_ELSE_EXPR that would receive the branching code as strings.

will return "10" without throwing an error.

Switch-case

A common feature of many programming languages is a function that maps values to other values. This is accessible via the SWITCH_MAP function.

returns 5.

If the matched value is not present, it stays unchanged.

returns 15.

Switch-case (ladder)

Chaining multiple IF_ELSE methods can become unreadable. This is why JIPipe provides the SWITCH and CASE(condition, value) functions. The surrounding SWITCH would select the first CASE where the condition is true and return its value.

returns "five".

Switch-case (ladder, legacy)

There is an alternative variant to SWITCH and CASE called SWITCH_CASE. Instead of having two functions, there is only one SWITCH_CASE function where the odd-indexed parameters are mapped to the condition and even-indexed parameters to the values.