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PDF Reducer


PDF Reducer is a reducer that produces a JSON containing the Base64 encoding and the path of a PDF file that is the result of merging PDF files that are taken from the output of blocks of the reference context.
In other words, a PDF Reducer block, put after a context whose iterations generate PDF files, merges those files in one PDF file.


Like any reducer, a PDF Reducer block has a virtual input made of the multiple outputs—one per iteration—of the blocks in the reference context. The parts of this input that represent the body and the name of the PDF files to merge in the output PDF file are indicated with a map defined in the Input tab of the block properties pop-up.

Block properties

The properties of a PDF reducer block are accessed by editing the block and are divided into these groups:

  • Basic properties:

    • Block name
    • Component version (read only)
    • Block ID (read only)
  • Functional:

    • Context to reduce: reference context. It is chosen from a drop-down. To remove the choice, select Clear .
    • PDF File name: the name of the PDF file to generate.
  • Deployment:

    • Timeout: execution timeout expressed in minutes (m) or seconds (s).
    • Replicas: number of required instances.
    • Consumer Number: number of threads of the consumer, the software module of the block that provides input to process by taking it from the block's work queue.
    • Memory: required memory.
    • CPU: thousandths of a CPU required (for example: 1000 = 1 CPU).
  • Input:

    • base64: the output key of one of the context blocks that contains the Base64 representation of the single PDF file to merge into the output PDF.
    • path: the key of the output of one of the context blocks that contains the path of the single PDF file to merge in the output PDF.

    To set both the properties above, use the drop-down to choose the corresponding key from the list of the output keys of the context blocks.

    The list is divided in groups, one group for each context block. Select the expand and collapse icons to the right of the block name or select the name of the block multiple times to show or hide the sub-list of output keys for that block.


    The drop-down list shows all the first-level keys that can, potentially, be available, but the keys that are actually there when executing the workflow may be less.

    To cancel the mapping process, select No mapping from the list or, if you already chose a key, select Clear .

  • Output: read-only, a memorandum of the contents of the output JSON object, that is:

    • The Base64 encoding of the PDF file.
    • The name of the PDF file.