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DocumentGenerator

Render data using a Handlebars template
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Overview

The DocumentGenerator node's "Render Template" operation allows you to generate text output by rendering input data through a Handlebars template. This is useful for dynamically creating documents, emails, reports, or any text-based content based on your workflow data.

Common scenarios:

  • Generating personalized email bodies from contact lists.
  • Creating custom-formatted reports from tabular data.
  • Producing templated messages or notifications using workflow variables.

Practical example:
If you have a list of users and want to send each a customized message, you can use this node to render the message body with user-specific details.

Properties

Display Name Type Meaning
Render All Items with One Template boolean If enabled, all input items are rendered together using a single template (useful for batch processing, e.g., tables). Otherwise, each item is rendered individually with its own template context.
Use a Template String boolean Choose whether to provide the template directly as a string (enabled) or fetch it from a URL (disabled).
Template String string The Handlebars template to use for rendering, entered directly in the node. Only shown if "Use a Template String" is enabled.
Template URL string The URL from which to fetch the Handlebars template. Only shown if "Use a Template String" is disabled.
Define a Custom Output Key boolean If enabled, lets you specify a custom property name for the rendered output instead of the default "text".
Output Key string The property name where the rendered text will be stored in the output. Only shown if "Define a Custom Output Key" is enabled.

Output

  • The node outputs an array of items, each containing a json object.
  • By default, the rendered text is placed under the text key in the json object. If a custom output key is defined, the rendered text appears under that key instead.

Output Structure Example

When rendering each item individually:

[
  {
    "json": {
      "text": "Rendered output for item 1"
    }
  },
  {
    "json": {
      "text": "Rendered output for item 2"
    }
  }
]

When rendering all items with one template:

[
  {
    "json": {
      "text": "Rendered output for all items"
    }
  }
]

Note: Replace "text" with your custom output key if specified.

  • No binary data is produced by this node.

Dependencies

  • External Library: Uses @jaredwray/fumanchu for Handlebars template rendering.
  • Template URL: If using a template URL, the node requires network access to fetch the template.
  • No credentials or API keys are required unless your template URL is protected.

Troubleshooting

Common Issues:

  • Invalid Handlebars Syntax:
    If your template contains errors, rendering will fail. Double-check your template against the Handlebars documentation.

  • Missing Required Fields:
    If required properties like "Template String" or "Template URL" are not provided, the node will throw an error.

  • Network Errors (Template URL):
    If the node cannot fetch the template from the provided URL (e.g., due to network issues or invalid URL), it will fail. Ensure the URL is correct and accessible.

  • Output Key Conflicts:
    If you define a custom output key that conflicts with existing fields in your data, it may overwrite them.

Error Messages:

  • "Cannot read property 'compile' of undefined" — Indicates a problem with the Handlebars library or template loading.
  • "Request failed with status code..." — Problem fetching the template from the URL; check connectivity and URL correctness.

Links and References

Discussion