Custom conversion functions for transfer objects

• Extensions + Custom DAO builder function
• Custom conversion functions for transfer objects
• Custom data portal functions

The transfer objects are used to pass the values of business object instances to the data access objects and the client application, respectively, and vice versa. The data transfer objects serve as courier between the business objects and the data access objects, the client transfer objects run between the business objects and the client application. In base case the values of all properties of a business object are copied to the transfer object. One ore more properties can be excluded from the transfer object using the flag argument of PropertyInfo constructor. For details see the Property definitions page.

In situations where passing the value of aproperty is conditional or it requires transformation, a custom function has to be used. These functions have a context argument of type TransferContext that provides the following property and methods:

• properties
  An array of PropertyInfo objects that define the properties of the business object.
• getValue( propertyName )
  The method expects the name of a property of the business object, and returns the value of the property. This method is undefined for read-only models in fromDto() functions.
• setValue( propertyName, value )
  The method expects the name of a property of the business object and its value, and writes the value into the property. This method is undefined for read-only models in toCto() functions.

In case of client transfer object methods, the permissions of the user to read or write the given properties are also checked.

The following custom conversion functions can be applied.

• toDto( context )

Argument context is the transfer context object, and the method returns the data transfer object. The method copies the values of the properties of the business object onto the data transfer object.

This method is invalid for read-only business objects.

The default function works like that:

function toDto(context) {
  var dto = {};
  context.properties.filter(function (property) {
    return property.isOnDto;
  }).forEach(function (property) {
    dto[property.name] = context.getValue(property.name);
  });
  return dto;
}

An alternative solution to change readily:

function toDto(context) {
  return {
    propertyName1: context.getValue('propertyName1'),
    propertyName2: context.getValue('propertyName2'),
    ...
    propertyNameN: context.getValue('propertyNameN')
  };
}

• fromDto( context, dto )

Argument context is the transfer context object, argument dto is the data transfer object. The method copies the values of the properties of data transfer object onto the the business object.

The default function works like that:

function fromDto(context, dto) {
  context.properties.filter(function (property) {
    return property.isOnDto;
  }).forEach(function (property) {
    if (dto.hasOwnProperty(property.name) && typeof dto[property.name] !== 'function') {
      context.setValue(property.name, dto[property.name]);
    }
  });
}

An alternative solution to change easily:

function fromDto(context, dto) {
  context.setValue('propertyName1',  dto.propertyName1);
  context.setValue('propertyName2',  dto.propertyName2);
  ...
  context.setValue('propertyNameN',  dto.propertyNameN);
}

• toCto( context )

Argument context is the transfer context object, and the method returns the client transfer object. The method copies the values of the properties of the business object onto the client transfer object.

This method is invalid for command objects.

The default function works like that:

function toCto(context) {
  var cto = {};
  context.properties.filter(function (property) {
    return property.isOnCto;
  }).forEach(function (property) {
    cto[property.name] = context.getValue(property.name);
  });
  return cto;
}

An alternative solution to change lightly:

function toCto(context) {
  return {
    propertyName1: this.propertyName1,
    propertyName2: this.propertyName2,
    ...
    propertyNameN: this.propertyNameN
  };
}

• fromCto( context, cto )

Argument context is the transfer context object, argument cto is the client transfer object. The method copies the values of the properties of client transfer object onto the the business object.

This method is invalid for command objects and read-only business objects.

The default function works like that:

function fromCto(context, cto) {
  if (cto && typeof cto === 'object') {
    context.properties.filter(function (property) {
      return property.isOnCto;
    }).forEach(function (property) {
      if (cto.hasOwnProperty(property.name) && typeof cto[property.name] !== 'function') {
        context.setValue(property.name, cto[property.name]);
      }
    });
  }
}

An alternative solution to change quickly:

function fromCto(context, cto) {
  this.propertyName1 = cto.propertyName1;
  this.propertyName2 = cto.propertyName2;
  ...
  this.propertyNameN = cto.propertyNameN;
}