@datafix/n8n-nodes-validator

This is an n8n community node. It lets you use validate items against a JSON schema in your n8n workflows.

• @datafix/n8n-nodes-validator
• How to use
• Configuration Options
  • Missing Fields
  • Conversion
  • Options
• Example
  • Schema
  • Matching data
• Resources

How to use

The node takes 2 inputs:

1. The data to be validated
2. The JSON schema against which to validate the data

The node will output the validation result, which includes whether the data is valid or not, and any validation errors if applicable. If the data is valid, the node will also output the validated data. If the data is invalid, the node will output the validation errors via a separate output.

Per key that you want to validate, the following properties can be set:

Configuration Options

Missing Fields

Adds fields to an item when they are missing from the input data but are defined in the schema.

The configured default value for each type is shared by all missing fields of that type. For example, if two missing fields both have type date, they will both receive the same configured default date value. You cannot configure separate default values per field here.

• Add Missing Fields > Adds fields that are defined in the schema but missing from the input data.
• Required Fields Only > When enabled, only missing fields marked as required in the schema are added.
• Default Value for String Fields > The value used when adding a missing string field.
• Default Value for Number Fields > The value used when adding a missing number field.
• Default Value for Boolean Fields > The value used when adding a missing boolean field.
• Default Value for Date Fields > The value used when adding a missing date field. The value must match the dateFormat defined for that field in the schema.
• Default Value for Time Fields > The value used when adding a missing time field. The value must match the timeFormat defined for that field in the schema.
• Default Value for DateTime Fields > The value used when adding a missing datetime field. The value must match the dateTimeFormat defined for that field in the schema.

Missing fields are added before conversion options are applied. This means newly added values can also be converted or adjusted by the options below.

Conversion

Applies automatic transformations to values before final validation. This can be used to normalize types, trim keys, limit lengths or decimals, and convert date, time, datetime, and boolean values.

• Auto Trim Keys > Removes leading and trailing whitespace from field names. For example, " name " becomes "name".
• Convert Types > Attempts to convert values to the type defined in the schema. For example, "123" can be converted to 123 when the field type is number.
• Apply Max Decimal Places > Reduces the number of digits after the decimal point to the field's configured maxDecimal value.
• Apply Max String Length > For string fields, limits the number of characters to maxStringLength. For number fields, limits the number of digits before the decimal point.
• Convert Boolean Values > Converts values recognized as valid true or false values into the configured output values.
• Converted True Value > The value used when converting a recognized true value.
• Converted False Value > The value used when converting a recognized false value.
• Convert Date Values > Parses date values using the field's dateFormat and converts them to the configured output format.
• Converted Date Format > The output format used when converting date values. For example, dd-MM-yyyy.
• Convert Time Values > Parses time values using the field's timeFormat and converts them to the configured output format.
• Converted Time Format > The output format used when converting time values. For example, HH:mm.
• Convert DateTime Values > Parses datetime values using the field's dateTimeFormat, applies the configured timezone where applicable, and converts them to the configured output format.
• Converted DateTime Format > The output format used when converting datetime values. For example, yyyy-MM-dd HH:mm:ss ZZ.

Conversion options are applied after missing fields have been added and before the final validation of the item.

Options

Controls general validation behavior and output settings that are not specific to missing-field handling or value conversion.

• Error Output Field Name > Sets the field name used to store validation errors on invalid items. The default is errors.
• Default Timezone > Sets the timezone used for date, time, and datetime values when no timezone is specified directly in the schema. A timezone defined in the schema takes precedence over this setting.

Example

For example, suppose you want to validate product data containing a name, price, quantity, and active status.

Schema

The schema defines the validation rules for each field:

[
  {
    "field": "name",
    "type": "string",
    "required": true,
    "maxStringLength": 100
  },
  {
    "field": "price",
    "type": "number",
    "required": true,
    "maxDecimal": 2
  },
  {
    "field": "quantity",
    "type": "number",
    "required": false,
    "maxDecimal": 0
  },
  {
    "field": "active",
    "type": "boolean",
    "required": true,
    "validTrueBooleans": [true, "true", "yes", 1],
    "validFalseBooleans": [false, "false", "no", 0]
  }
]

Matching data

The following items satisfy the schema:

[
  {
    "name": "Wireless Mouse",
    "price": 29.95,
    "quantity": 10,
    "active": true
  },
  {
    "name": "Mechanical Keyboard",
    "price": 89.99,
    "quantity": 5,
    "active": "yes"
  },
  {
    "name": "USB-C Cable",
    "price": 12.5,
    "active": 1
  }
]

In this example:

• name is required and may contain at most 100 characters.
• price is required and may contain at most 2 decimal places.
• quantity is optional and must be a whole number because maxDecimal is set to 0.
• active is required and accepts multiple representations of boolean values. For example, true, "yes", and 1 are all treated as true.

n8n is a fair-code licensed workflow automation platform.

Resources

• n8n community nodes documentation