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You can use this Snap to generate a JSON document for the next Snap in the Pipeline.



Support for Ultra Pipelines

Works in Ultra Pipelines

Limitations and Known Issues

Snap Input and Output

Input/OutputType of ViewNumber of ViewsExamples of Upstream and Downstream SnapsDescription


Retain one.

  • Min: 0
  • Max: 1
  • Mapper Snap
  • Copy Snap
  • Splitter Snap
This Snap can have an upstream Snap that can pass a JSON document in output view. 


Retain one.
  • Min: 1
  • Max: 1
  • Mapper Snap
  • Copy Snap
  • JSON Parser
  • JSON Formatter

This Snap generates a document that contains the expected result along with the original JSON document (when Pass through is enabled).

Snap Settings

Parameter NameData TypeDescriptionDefault ValueExample 
LabelStringN/AJSON Generator
Edit JSONApache Velocity template

Optional. Launches the JSON editor which will allow defining JSON. The editor will load an existing JSON document if it was defined previously. The editor lets you save JSON in SnapLogic's file system or import existing JSON documents from it.

Note that this text is treated as an Apache Velocity template, so you can substitute values from input documents or the pipeline parameters. The Apache Velocity template can be used to pass dynamic values from upstream Snaps. For more information, see

Empty JSON fileFile with JSON content
Process ArrayCheckboxOptional. The Process array property specifies whether or not the Component should take a root JSON array and write each element of the array as a JSON document. SelectedSelected
Pass throughCheckboxOptional. Use this property to pass the data in the input document through to the output document and merge it under the key 'original'. See example for more details.DeselectedSelected

Indicates how the Snap must be executed. Available options are:

  • Validate & Execute: Performs limited execution of the Snap (up to 50 records) during Pipeline validation; performs full execution of the Snap (unlimited records) during Pipeline execution.
  • Execute only: Performs full execution of the Snap during Pipeline execution; does not execute the Snap during Pipeline validation.
  • Disabled: Disables the Snap and, by extension, its downstream Snaps.

Validate & ExecuteExecute only


Unexpected character ('{' (code 123))Enter the error message that is displayed. 

The array entries in the JSON file do not follow the syntax. A comma ',' is expected before the beginning of every second array—'{'.

Briefly describe why this error is triggered. An experienced user will be able to troubleshoot the error looking at the reason itself.
Verify the array at the row and column mentioned beside the error message using the Edit JSON feature and add a comma appropriately.

List the steps that the user must take, if necessary, to rectify this error. If a procedure is extensive, add it as a separate section after this table and reference it with a link in this cell.

Editing JSON

Clicking Edit JSON will launch the JSON Editor. The JSON will be stored in the Snap (after clicking OK). The JSON can be exported to SnapLogic's file system using the export action or be imported from there using the import action.

The JSON can be customized to meet specific needs, such as having: 

  1. Static content that produces one output document OR
  2. A list of static documents within an array definition which can then be transformed into multiple documents upstream by using a JSON Splitter Snap OR
  3.  Variables in the JSON, which can be substituted with document values from the input view of the Snap.

Escaping Special Characters

Additionally, some special characters can be escaped using the following notations.

Type To pass this valueSpecify
Single characters
#[$]# or \$
JSON String

For information on how to use pipeline parameters and field values within this Snap, see Velocity Templates in Generator Snaps in Parameters and Fields.


Using the Pass Through Functionality

Consider the following Pipeline that combines two simple datasets.

Download this Pipeline

Snap Configurations

JSON Object (JSON Generator Snap with Pass through disabled)

This JSON Generator Snap, JSON Object, is used as an input by the downstream JSON Generator Snap, Combined JSON.

Snap Configuration (JSON Object)
Input JSONOutput JSON

Combined JSON (JSON Generator Snap with Pass through enabled)

Snap Configuration (Combined JSON)

Input JSONOutput JSON

The output JSON contains:

Input Schema Types

This example Pipeline demonstrates the difference in the input schema types on selecting and deselecting Support Type Extensions checkbox.

There is no difference in the preview output of JSON Generator or JSON Parser as the JSON representation remains the same. But the Mapper Snaps downstream of the JSON Generator Snap shows the difference in the Input Schema types.

The input schema in Mapper Snap when you deselect Support Type Extensions checkbox in the JSON Generator Snap is as follows. The Snap displays the SnapLogic-specific syntax in the Input Schema.

Here's the same Mapper Snap when you select the Support Type Extensions checkbox. Note the data types in the Input Schema—the Snap does not display the SnapLogic-specific syntax in the Input Schema.

Similarly, here's a Mapper Snap showing the JSON Parser output when you deselect the Support Type Extensions checkbox.

Here's the same Mapper when you select the Support Type Extensions checkbox.

The Support Type Extensions state affects the JSON Formatter's output. When you deselect this checkbox, the SnapLogic-specific syntax is not used; the Snap uses a string representation for each of the special objects.

Here's the output when you select the Support Type Extensions checkbox:


  1. Download and import the Pipeline into SnapLogic.
  2. Configure Snap accounts as applicable.
  3. Provide Pipeline parameters as applicable.

See Also