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Form Schema

The form schema is used by an Action to generate a form that the user can fillout when requesting a new signal. The forms will be validated with the schema you define and will not let the user request the signal without a valididating all the requirements of the schema. SignalFire's Form schema is based on the AJV Schema format.

Common Schema Properties​

These are some of the most commonly used properties and keywords for JSON schemas for AJV, to learn about more see AJV documenation. JSON schemas can become more complex as you define intricate validation rules for your data structures. The schema structure allows you to define powerful and flexible validation rules for your JSON data.

Types​

Defines the JSON data type expected for the current schema. Common types include object, array, string, number, boolean, and null.

"type": "object"

Object Properties​

Describes the expected properties and their respective schemas for an object.

"properties": {
    "name": { "type": "string" },
    "age": { "type": "integer" }
}

Number Minimum and Maximum​

Sets the minimum and maximum numeric values allowed for a number.

"minimum": 0,
"maximum": 100

String Format​

Provides additional constraints on string values, often used for common formats like dates, emails, and URIs. Learn about all formats?

"format": "email"

String Patterns​

Defines a regular expression pattern that a string property must match.

"pattern": "^\\d{3}-\\d{2}-\\d{4}$"

Enums​

Specifies an array of allowed values. The data must match one of the values in the array.

"enum": ["red", "green", "blue"]

Object Required​

Lists the required properties for an object. It specifies which properties must be present in the validated data.

"required": ["name", "age"]

Object Dependencies​

Describes dependencies between properties. It specifies which properties are required when certain other properties are present.

"dependencies": {
    "required_property": ["dependent_property"]
}

Array Items​

Defines the schema for elements within an array. It can be used to specify a schema for all elements in an array or a different schema for each element.

"items": { "type": "string" }

Examples​

Example 1: Simple Object Schema​

This schema defines a simple JSON object with two properties: "name" and "age." Both properties are required, and "age" must be a positive integer.

{
    "type": "object",
    "properties": {
        "name": { "type": "string" },
        "age": { "type": "integer", "minimum": 0 }
    },
    "required": ["name", "age"]
}

Example 2: Enum Values Schema​

This schema defines an object where the "color" property must have one of three allowed values: "red," "green," or "blue."

{
    "type": "object",
    "properties": {
        "color": {
            "type": "string",
            "enum": ["red", "green", "blue"]
        }
    },
    "required": ["color"]
}

Example 3: Schema with Dependencies​

This schema defines an object where "property_a" and "property_b" are required. Additionally, if "property_a" is present, "property_c" must also be present.

{
    "type": "object",
    "properties": {
        "property_a": { "type": "string" },
        "property_b": { "type": "number" },
        "property_c": { "type": "boolean" }
    },
    "required": ["property_a", "property_b"],
    "dependencies": {
        "property_a": ["property_c"]
    }
}

Example 4: Conditional Properties​

This schema defines an object with conditional properties. Depending on the "category" value, different properties are required. For example, if "category" is "book," then "author" and "pages" are required.

{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "type": "object",
    "properties": {
        "category": { "type": "string" },
        "title": { "type": "string" },
        "author": { "type": "string" },
        "pages": { "type": "integer" }
    },
    "required": ["category", "title"],
    "if": { "properties": { "category": { "const": "book" } } },
    "then": { "required": ["author", "pages"] }
}