`pdf_metadata`

Extract metadata from a PDF file (document info dictionary + page count).

Parameters

pathstringone of path or source_key: PDF file path
source_keystringone of path or source_key: Context key containing a file path
output_keystringdefault "metadata": Prefix for output key

Providing both path and source_key is an error.

Context Output

<output_key> — object containing metadata:
- pages — page count
- title, author, subject, keywords, creator, producer, created, modified when present

Example

local flow = Flow.new("pdf_metadata_demo")

flow:step("meta", nodes.pdf_metadata({
    path = "examples/fixtures/ironflow-sample.pdf",
    output_key = "pdf_meta"
}))

-- Interpolation does not evaluate fallback expressions, so normalize the
-- optional field in an explicit workflow step.
flow:step("metadata_defaults", function(ctx)
    return {
        pdf_creator = ctx.pdf_meta.creator or "unknown"
    }
end):depends_on("meta")

flow:step("log", nodes.log({
    message = "PDF has ${ctx.pdf_meta.pages} page(s), produced by ${ctx.pdf_creator}"
})):depends_on("metadata_defaults")

return flow