Every Format Is a Costume the Data Model Wears
How DataWeave's reader/writer model turns JSON, Java, and everything else into the same shape — and how reader/writer properties tune both sides.
DataWeave in the Wild
Real formats and real problems — XML, CSV and flat files, dates, the standard library, modules, testing, and streaming at scale.
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Taming XML Without Losing Your Weekend
Attributes, namespaces, repeated elements, mixed content, CDATA — and the single-versus-many array gotcha that eats an afternoon if you don't know it.
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CSV, Fixed-Width, and the Files That Refuse to Die
Delimited and positional data in DataWeave — CSV reader/writer properties, schema-driven fixed-width parsing, and a nod to Excel and multipart.
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Dates, Time Zones, and the mm That Meant Minutes
DataWeave's temporal types, format-schema parsing and formatting, Period arithmetic, and the timezone shifts and coercion bugs that bite everyone once.
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The Standard Library You Keep Rewriting By Hand
A working tour of dw::core — the Strings, Arrays, and Objects functions that actually earn their keep, plus DataWeave's regex, and how to find everything else.
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Your Transform Is Code, So Test It Like Code
Pull reusable logic into a .dwl module, import it cleanly, and pin its behaviour with the dw CLI, MUnit, and golden-file tests — because a transform is code, and pure functions are a joy to test.
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When the Payload Is Bigger Than the Heap
How DataWeave streams — deferred evaluation, streaming reader properties, @StreamCapable, and deferred output — and the everyday operations that quietly pull your whole gigabyte into memory.
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One Ugly XML Feed, One Clean Report
The capstone: take a namespaced XML order feed with repeated elements, mixed date formats, and money as strings, and build a normalized JSON report end to end — selectors, a helper module, dates, coercion, groupBy+reduce, and conditional keys, in a few reasoned steps.