EFactory

struct EFactory

Overview

EFactory provides the factory pattern for creating instances of classes defined in a metamodel package. Each factory is associated with a specific EPackage and can create instances of the classes in that package.

Key Capabilities

• Create Objects: Instantiate objects of a given class using create(_:)

• Parse Data Types: Convert string literals to typed values using createFromString(_:_:)

• Convert to Strings: Convert typed values to string literals using convertToString(_:_:)

Example

let companyPackage = EPackage(
    name: "company",
    nsURI: "http://example.org/company",
    nsPrefix: "company"
)

let factory = EFactory(ePackage: companyPackage)

// Create an Employee instance (in practice, would return a proper object)
if let employeeClass = companyPackage.getEClass("Employee") {
    let employee = factory.create(employeeClass)
    print("Created instance of \(employee.eClass.name)")
}

// Parse a string into an Int
let intType = EDataType(name: "EInt")
if let value = factory.createFromString(intType, "42") as? Int {
    print("Parsed value: \(value)")
}

Important Note

This basic implementation creates generic EObject instances. In a complete implementation, factories would be code-generated or use dynamic proxies to create specific typed instances with proper feature storage.