Function Parameters

Overview

You can send parameters to data model functions through the REST API. The parameters are received in the declared parameters of the class functions on the server side.

General Rules

The following rules must be followed:

In functions called through POST requests, parameters must be passed in the body of the POST request.
In functions called through GET requests, parameters must be passed in the URL with "?$params=" syntax.
JSON Format: Parameters must be enclosed within a collection (JSON format).
Supported Data Types: All scalar data types supported in JSON collections can be passed as parameters, including strings, numbers, booleans, and dates.
Entities and Entity Selections as parameters: Both individual entities and entity selections can be passed as parameters. The JSON object must contain specific attributes (__DATACLASS, __ENTITY, __ENTITIES, __DATASET) to identify and assign data to the corresponding ORDA objects.

Scalar Value Parameter

For scalar value parameters, simply enclose them in a collection in the body of the POST request. For instance, consider a Product dataclass with a function calculateDiscount that takes numeric parameters:

tip

All JSON data types are supported, including JSON pointers. Dates can be conveyed as strings adhering to ISO 8601 format (e.g., "2020-08-22T22:00:000Z").

For example, with a dataclass function getCities() receiving text parameters:

POST request

/rest/City/getCities

Parameters in body: ["Aguada","Paris"]

GET request

/rest/City/getCities?$params='["Aguada","Paris"]'

Example

Server-side Function Code:

exposed function calculateDiscount(price : number, discountRate : number) : number
    var discountedPrice : number
    discountedPrice = price*(1-discountRate)
    return discountedPrice

POST request

POST {{ApiEndpoint}}/rest/Product/calculateDiscount

Body of the request:

[100, 0.15]

GET request

GET {{ApiEndpoint}}/rest/Product/calculateDiscount?$params='[100,0.15]'`

Response

{
  "result": 85
}

Fallback Behavior

If parameters are missing or invalid:

Missing Parameters: If any parameters are missing, the function will return an error indicating the missing parameter.

{
  "__ERROR": [
    {
      "message": "Missing parameter 'price'",
      "componentSignature": "ds",
      "errCode": 1001
    }
  ]
}

Invalid Parameters: If parameters are of incorrect type or format, the function will return an error specifying the type mismatch or format issue.

{
  "__ERROR": [
    {
      "message": "Invalid parameter type for 'discountRate'. Expected 'number'.",
      "componentSignature": "ds",
      "errCode": 1002
    }
  ]
}

Entity Parameter

When passing an entity as a parameter, the entity is referenced on the server through its key (__KEY property). If the key is omitted, a new entity is created in memory on the server.

Additionally, attribute values for the entity can be passed, automatically utilized for the entity on the server.

info

Modified attribute values for an existing entity prompt automatic execution of the called ORDA data model function on the server. This enables result examination post-business rule application from the client application, facilitating informed decisions regarding entity saving on the server.

Parameter Specifications

Property	Type	Requirement	Description
Attributes of the entity	mixed	Optional	Values to modify.
__DATACLASS	String	Mandatory	Indicates the Dataclass of the entity.
__ENTITY	Boolean	Mandatory	True to indicate that the parameter is an entity.
__KEY	Mixed	Optional	Primary key of the entity. If not provided, a new entity is created on the server with the given attributes. If provided, the entity corresponding to the key is loaded on the server with the given attributes.

Example

Server-side Function Code:

exposed function updateEmployee(employeeData : object) : boolean
    var employee : cs.UsersEntity
    var status : object

    if (not(employeeData.__KEY = null))
        employee = ds.Employee.get(employeeData.__KEY)
    else
        employee = ds.Employee.new()
    end

    employee.fromObject(employeeData)
    status = employee.save()

    return status.success

Request:

POST {{ApiEndpoint}}/rest/Employee/updateEmployee

Body of the request:

{
  "__DATACLASS": "Employee",
  "__ENTITY": true,
  "__KEY": 1,
  "firstName": "John",
  "lastName": "Doe",
  "salary": 75000
}

Response:

{
  "result": true
}

Fallback Behavior

If the key or required attributes are missing:

Missing Key: If the __KEY is missing, a new entity is created with the provided attributes.

Invalid Key: If the __KEY is invalid or not found, the function will return an error indicating the entity could not be found.

{
  "__ERROR": [
    {
      "message": "Entity with key '1' not found",
      "componentSignature": "ds",
      "errCode": 1003
    }
  ]
}

Missing Attributes: If required attributes are missing, the function will return an error specifying the missing attributes.
```
{
  "__ERROR": [
    {
      "message": "Missing required attribute 'lastName'",
      "componentSignature": "ds",
      "errCode": 1004
    }
  ]
}
```
Empty Attribute Values: If attribute values are provided but empty or null, the function will return an error specifying the attributes with empty values.

Copier le code
{
  "__ERROR": [
    {
      "message": "Empty or null value provided for attribute 'firstName'. Please provide a valid value.",
      "componentSignature": "ds",
      "errCode": 1011
    }
  ]
}

Entity selection Parameter

Before passing an entity selection as a parameter, you need to define it using $method=entityset.

Parameter Specifications

Property	Type	Requirement	Description
Attributes of the entity	mixed	Optional	Values to modify.
__DATASET	String	Mandatory	entitySetID (ID) of the entity selection
__ENTITIES	Boolean	Mandatory	True to indicate that the parameter is an entity selection.

Example

Server-side Function Code:

exposed function applyDiscount(productSelection : object, discount : number) : boolean
    var products : cs.ProductSelection
    var product : cs.ProductEntity

    products = ds.Product.getEntitySelection(productSelection.__DATASET)
    forEach (product, products)
        product.price = product.price*(1-discount/100)
        product.save()
    end
    return true

Request:

POST {{ApiEndpoint}}/rest/Product/applyDiscount

Body of the request:

[
  {
    "__ENTITIES": true,
    "__DATASET": "9B9C053A111E4A288E9C1E48965FE671"
  },
  10
]

Response:

{
  "result": true
}

Fallback Behavior

If the entity selection or discount is missing or invalid:

Missing Entity Selection: If the __DATASET is missing, the function will return an error indicating the entity selection parameter is missing.

{
  "__ERROR": [
    {
      "message": "Missing parameter '__DATASET'",
      "componentSignature": "ds",
      "errCode": 1005
    }
  ]
}

Invalid Entity Selection: If the __DATASET is invalid or not found, the function will return an error indicating the entity selection could not be found.

{
  "__ERROR": [
    {
      "message": "Entity selection with ID '9B9C053A111E4A288E9C1E48965FE671' not found",
      "componentSignature": "ds",
      "errCode": 1006
    }
  ]
}

Missing Discount: If the discount parameter is missing, the function will use a default discount value.
```
{
  "result": true,
  "message": "No discount provided, default discount of 10% applied"
}
```

Invalid Discount: If the discount parameter is invalid, the function will return an error specifying the issue.

{
  "__ERROR": [
    {
      "message": "Invalid discount value. Expected 'number', received 'string'",
      "componentSignature": "ds",
      "errCode": 1007
    }
  ]
}

GET request examples

Returning a document

You want to propose a link to download the user manual for a selected product with several formats available. You write a getUserManual() function of the Products dataclass. You return an object of the OutgoingMessage class.

// Product dataclass
exposed onHTTPGet function getUserManual(productId : integer, type : string) : 4D.OutgoingMessage
  
var vfile : 4D.File
var response = 4D.OutgoingMessage.new()
var doc = "/SOURCES/Shared/User manuals/product_" + string(productId)

switch 
  : (type == "pdf")
    vfile = file(doc+".pdf")
    response.setBody(vfile.getContent()) // This is binary content 
    response.setHeader("Content-Type", "application/pdf")
      
  : (type == "jpeg")
    vfile = file(doc+".jpeg")
    response.setBody(vfile.getContent()) // This is binary content 
    response.setHeader("Content-Type", "image/jpeg")
end 
  
return response

You can call the function using a request like:

GET {{ApiEndpoint}}/rest/Products/getUserManual?$params='[1,"pdf"]'

Using an entity to download a PDF document

Same example as above but you want to pass an entity as parameter to the datastore function.

// Product dataclass
exposed onHTTPGet function getUserManual(product : cs.ProductEntity) : 4D.OutgoingMessage
  
  var vfile : 4D.File
  var response = 4D.OutgoingMessage.new()
  
  vfile = file("/SOURCES/Shared/User manuals/"+product.name+".pdf")
  response.setBody(vfile.getContent())
  response.setHeader("Content-Type", "application/pdf")
  
  return response

You can call the function using this request:

GET {{ApiEndpoint}}/rest/Product/getUserManual?$params='[{"__DATACLASS":"Product","__ENTITY":true,"__KEY":41}]'

Overview​

General Rules​

Scalar Value Parameter​

POST request​

GET request​

Example​

POST request​

GET request​

Response​

Fallback Behavior​

Entity Parameter​

Parameter Specifications​

Example​

Fallback Behavior​

Entity selection Parameter​

Parameter Specifications​

Example​

Fallback Behavior​

GET request examples​

Returning a document​

Using an entity to download a PDF document​

Overview

General Rules

Scalar Value Parameter

POST request

GET request

Example

POST request

GET request

Response

Fallback Behavior

Entity Parameter

Parameter Specifications

Example

Fallback Behavior

Entity selection Parameter

Parameter Specifications

Example

Fallback Behavior

GET request examples

Returning a document

Using an entity to download a PDF document