DSL Reference

Complete reference for the DSL (Domain Specific Language) for business rules in Fyso.

General Structure

{
  "type": "compute | validate | action",
  "triggers": ["campo1", "campo2"],
  "triggerType": "field_change | before_save | after_save | on_load",
  "compute": { ... },
  "validate": [ ... ],
  "transform": { ... },
  "actions": [ ... ]
}

Compute

Calculates values automatically. Supports several formats:

Simple Formula (shorthand)

{
  "compute": {
    "total": "cantidad * precio"
  }
}

The shorthand is internally normalized to:

{
  "compute": {
    "total": { "type": "formula", "expression": "cantidad * precio" }
  }
}

Explicit Formula

{
  "compute": {
    "iva": { "type": "formula", "expression": "subtotal * 0.21" },
    "total": { "type": "formula", "expression": "subtotal + iva" }
  }
}

Conditional

Calculates a value based on conditions:

{
  "compute": {
    "descuento": {
      "type": "conditional",
      "conditions": [
        { "when": "cantidad >= 100", "then": "0.15" },
        { "when": "cantidad >= 50", "then": "0.10" },
        { "when": "cantidad >= 10", "then": "0.05" }
      ],
      "default": "0"
    }
  }
}

Lookup

Looks up a value in another entity:

{
  "compute": {
    "precio_unitario": {
      "type": "lookup",
      "entity": "productos",
      "matchField": "id",
      "matchValue": "producto_id",
      "resultField": "precio"
    }
  }
}

Property	Type	Description
entity	string	Entity to search in
matchField	string	Field in the target entity to match against
matchValue	string	Field in the current record containing the value to search for
resultField	string	Field in the target entity whose value to return

Aggregate

Aggregates values from multiple records of another entity:

{
  "compute": {
    "total_lineas": {
      "type": "aggregate",
      "entity": "lineas_factura",
      "aggregateOp": "sum",
      "aggregateField": "subtotal",
      "filter": { "factura_id": "id" }
    },
    "cantidad_items": {
      "type": "aggregate",
      "entity": "lineas_factura",
      "aggregateOp": "count",
      "filter": { "factura_id": "id" }
    }
  }
}

Property	Type	Description
entity	string	Entity to aggregate
aggregateOp	string	Operation: "sum" or "count"
aggregateField	string	Field to sum (required for sum)
filter	object	Filter: { target_field: "current_field" }

Validate

Array of validation rules:

{
  "validate": [
    {
      "id": "precio_positivo",
      "condition": "precio > 0",
      "message": "El precio debe ser mayor a cero",
      "severity": "error",
      "field": "precio"
    }
  ]
}

Property	Type	Required	Description
id	string	Yes	Unique identifier for the validation
condition	string	Yes	Boolean expression that must be true
message	string	Yes	Error message if the condition is false
severity	string	Yes	"error" (blocks save), "warning", "info"
field	string	No	Field to associate the error with in the UI

Transform

Transforms field values:

{
  "transform": {
    "nombre": { "type": "uppercase" },
    "email": { "type": "lowercase" },
    "descripcion": { "type": "trim" },
    "precio": { "type": "round", "decimals": 2 }
  }
}

Type	Description
uppercase	Converts to uppercase
lowercase	Converts to lowercase
trim	Removes leading and trailing whitespace
round	Rounds to N decimal places

Actions

Side effects that execute after saving:

{
  "actions": [
    {
      "type": "update_related",
      "entity": "pedidos",
      "recordId": "pedido_id",
      "data": {
        "total": {
          "type": "aggregate",
          "entity": "lineas",
          "aggregateOp": "sum",
          "aggregateField": "subtotal",
          "filter": { "pedido_id": "pedido_id" }
        }
      }
    }
  ]
}

Allowed Operators

Category	Operators
Arithmetic	+, -, *, /
Comparison	>, <, >=, <=, ==, !=
Logical	and, or

Allowed Functions

Function	Description	Example
round(x, n)	Rounds to n decimal places	round(total, 2)
coalesce(a, b)	First non-null value	coalesce(descuento, 0)
abs(x)	Absolute value	abs(diferencia)
min(a, b)	Minimum	min(stock, pedido)
max(a, b)	Maximum	max(precio, precio_minimo)
floor(x)	Round down	floor(cantidad)
ceil(x)	Round up	ceil(horas)
len(s)	String length	len(nombre)
upper(s)	Uppercase	upper(codigo)
lower(s)	Lowercase	lower(email)
trim(s)	Remove whitespace	trim(nombre)
now()	Current date and time	now()
today()	Current date	today()