Change Things in the Model

Last update: Download PDF Edit

All units and elements can be freely altered after loading as long as you adhere to the type system. The properties id, container, structureTypeName, isLoaded and unit, as defined on the IStructure object, should not be used: these are (mostly) for internal purposes.

To create new units, you need to pass the parent structural unit to the constructor.

To create new elements, use the create methods, as this will create an element detached from the model. Please note that after creating an element, you have to assign it to a property before it actually becomes part of your model. For example, a new Attribute element should be pushed onto the attributes array of an entity. If you want to create an element and attach it to the model directly, you can use createIn.

An element is always in a specific state: new, attached, detached, or deleted. The state determines what changes can be applied to the element. For a full description of these states and their characteristics, see Element States.

All non-list-like properties can be altered simply using assignments. List-like properties are essentially JavaScript arrays, so to alter them you can just replace them or use JavaScript’s built-in array functions such as push.

References are automatically resolved by the SDK. This means you can just assign or read references directly using fully-typed objects. For each property that refers to a concept in another unit, there is also a read-only property available with <propertyName>QualifiedName (or <propertyName>QualifiedNames for list-like properties) that gives the string representation of the references.

The following example function creates a new entity with an attribute given a domain model:

import {domainmodels} from "mendixmodelsdk";

function createEntity(domainModel : domainmodels.DomainModel, entityName : string, attributeName : string) {
    const newEntity = domainmodels.Entity.createIn(domainModel); = entityName;

	// location on the canvas in the Mendix Studio Pro:
	newEntity.location = { 'x': 100, 'y': 100 };

    // new attribute (which is by default a string attribute):
    const newAttribute = domainmodels.Attribute.createIn(newEntity); = attributeName;

Continue with How to Close the Server Connection.