WEL standard library

The standard library is the set of functions built into WEL (Workato Expression Language). It ships with the language, so there is nothing to install, import, or connect. Every function is available in every expression.

FEATURE AVAILABILITY

WEL is currently available to select customers. Contact your Customer Success Representative to confirm whether it is available in your workspace.

Quick reference

WEL organizes functions into the following categories:

CategoryDescription
StringCheck, clean, extract, and replace text.
ListMap, filter, sort, group, join, and aggregate.
MapRead, merge, and reshape key-value data.
Deep mapCollect or transform values at any depth in a nested structure.
TemporalRead, calculate with, and move between dates, times, and durations.
NumericRound numbers and test numeric types.
FormattingRender values as display strings.
ConversionConstruct a value of a given type.
CommonMeasure length, test presence, and inspect type.
JSONParse, serialize, and query JSON.
EncodingConvert between text and bytes in a named encoding.
EscapeEscape a value for CSV, HTML, SOQL, and other formats.
UnicodeHandle grapheme clusters, normalization, and Japanese text.
BinaryWork with raw byte data.
CryptoHash, sign, and encrypt using HMAC, JWT, PBKDF2, and AES.
RandomGenerate UUIDs and random values.

Call a function

Call a function directly, or pipe a value into it with >>:

text
upper(_.status)
_.status >> upper

_ is the input variable that contains the data your expression receives. _.status reads the status field of the input. Refer to Input variables for details.

The piped value fills the function's first argument. Write any other arguments normally:

text
_.order_id >> starts_with?('SO-')

The pipe form reads left to right, which makes it the better choice when you chain several steps:

text
_.email >> trim >> lower

Refer to Operators for the full pipeline family.

Types are strict

WEL doesn't coerce arguments to make a call succeed. Passing a number where a function expects a String raises E100 rather than silently converting it. Use a conversion function to make the intended type explicit.

This is deliberate. Silent coercion is the most common cause of a transformation running without an error but producing the wrong result.

The exceptions are string interpolation, which always converts automatically, and two Transform data action flags that configure specific coercions.

  • Data types: The 16 WEL data types and how each represents a value.
  • Operators: More information about the pipeline family of operators.
  • Cookbook: Examples of common integration problems.
  • Error codes: Troubleshoot job failures.

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