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Overview

Use this Snap to consolidate multiple input streams into a single output document, where each input stream is displayed as a a label containing the records that were received by that input view.

It is also important to note that this Snap does not complete executing until the execution of all upstream Snaps is done.

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Prerequisites

This Snap collects multiple input documents into a single output document; hence there are system memory limitations, and it should not be used for massive data propagation. If large amounts of data are required, offload your data before Snap execution. You can also write your data to a file or database; then, after Snap execution completes, you can use a Reader Snap (File Reader, S3 Reader, and so on) to read from the offloaded data source.

Limitations

This Snap does not have error views. If the Snap fails during validation or execution, documents are not passed through, and you receive an error message. 

Support for Ultra Pipelines

Does not support Ultra Pipelines.

Snap Views

TypeFormatNumber of ViewsExamples of Compatible Upstream and Downstream SnapsDescription
Input Document
  • Min: 1
  • Max: ∞
  • Mapper
  • JSON Parser
  • Join
One or more documents containing records that must be passed on to downstream Snaps for further processing.
OutputDocument
  • Min: 1
  • Max: 1
  • Copy
  • Join
  • Common Words

A single document that contains all the records received from the various upstream Snaps.

Error

Error handling is a generic way to handle errors without losing data or failing the Snap execution. You can handle the errors that the Snap might encounter when running the pipeline by choosing one of the following options from the When errors occur list under the Views tab:

  • Stop Pipeline Execution: Stops the current pipeline execution if the Snap encounters an error.

  • Discard Error Data and Continue: Ignores the error, discards that record, and continues with the remaining records.

  • Route Error Data to Error View: Routes the error data to an error view without stopping the Snap execution.

Learn more about Error handling in Pipelines.

Snap Settings

  • Asterisk ( * ): Indicates a mandatory field.

  • Suggestion icon (): Indicates a list that is dynamically populated based on the configuration.

  • Expression icon ( ): Indicates the value is an expression (if enabled) or a static value (if disabled). Learn more about Using Expressions in SnapLogic.

  • Add icon (  ): Indicates that you can add fields in the field set.

  • Remove icon ( ): Indicates that you can remove fields from the field set.


Field NameField TypeDescription

Label*


Default Value: Gate
Example: Ensure Complete Execution

StringThe name for the Snap. You can modify this to be more specific, especially if you have more than one of the same Snap in your pipeline.

Ignore Empty Stream


Default Value: Deselected
Example: Ensure Complete Execution

Checkbox

Select this checkbox if you do not want this Snap to produce any output document.

When you deselect this checkbox, the Snap writes an empty document to the output view.

Output Document Content*


Default Value: All input documents
Example: Document count and first document for each input

Dropdown list

Choose one of the following options to determine the content of the output document:

  • All inputs documents
  • Document count and first document for each input: 
  • Document count and final document for each input



Snap Execution


Default Value: Validate & Execute
Example: Execute only

Dropdown list

Select one of the following three modes in which the Snap executes:

  • Validate & Execute: Performs limited execution of the Snap, and generates a data preview during pipeline validation. Subsequently, performs full execution of the Snap (unlimited records) during pipeline runtime.

  • Execute only: Performs full execution of the Snap during pipeline execution without generating preview data.

  • Disabled: Disables the Snap and all Snaps that are downstream from it.

Examples

Combining Completed Upstream Execution Output Using the Gate Snap

This example demonstrates how you can use the Gate Snap to combine the complete output of multiple upstream Snaps into a single document. This example also shows how the Gate Snap doesn't offer any output until all upstream Snaps are executed.

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Understanding the Pipeline

  1. Configure the File Reader Snap to the pipeline and configure it to read a CSV file containing contact information:


  2. Configure a CSV Parser Snap to read the input binary data as CSV. Once this Snap executes, you can view the contents of the file that the File Reader Snap read:


  3. You create a separate branch of the Pipeline by adding an unconnected REST Get Snap. You configure the Snap to retrieve contact data from HubSpot, which typically offers data in pages of 20 records each. You use the Has next and Next URL fields to specify how the Snap can retrieve additional pages of data. For step-by-step information on how to use the REST Get Snap to perform this task, see Retrieving Contact Information from HubSpot.


    The REST Get Snap retrieves the data in pages of 20 as requested until the value of the has-more variable changes to false:

    Note that until the REST Snap completes executing, the Gate Snap doesn't start reading data from any of its input views.



  4. You create another branch of the Pipeline by adding a JSON Generator Snap that provides customer information:


  5. You add a Gate Snap and configure it to have three input views:


    Make no further changes to the Gate Snap and connect its three inputs to each branch you created in the steps above.

  6. Save and run the Pipeline. The Gate Snap now collects the completed inputs from all upstream branches and offers them all as separate arrays in a single output document:


  7. To check how the Gate Snap behaves when one of the Snaps does not offer any output, you introduce an error into the REST Get Snap:


  8. Save and re-execute the Pipeline. The Gate Snap now offers an output that contains all the data received from the File Reader and JSON Generator branches, but in the output associated with the REST Get Snap, it outputs a null record:

Download this Pipeline

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