Currently, in the swift3 language, if you have an optional integer, number, or boolean property in a model, then the generated swift3 model class might look like:
class SomeModel {
var someInt: Int?
var someFloat: Float?
var someDouble: Double?
var someBool: Bool?
}
This works fine if you are accessing this model only from Swift code. However, it is very common for iOS codebases to contain both Swift AND Objective-C. If you need to access this model from Objective-C, then those 4 properties are not accessible, since Optional scalars do not translate to Objective-C.
Therefore, in the swift3 language, we want to add some code for Objective-C compatibility:
1. We add a "objCompatible" boolean command-line option. If objCompatible=true, then this enables some additional code generation to make these types of properties accessible from Objective-C. If objCompatible=false, then the generated code is exactly as it currently is. The default is objcCopmatible=false.
2. If objCompatible=true, then for these types of Objective-C-inaccessible properties (Optional scalars), then we add a "x-swift-optional-scalar=true" vendor extension in the CodegenProperty.
3. Then, in the model.mustache template, if we see x-swift-optional-scalar=true, then we add an additional computed property which returns an optional NSNumber.
So, for example, when objcCompatible=false (the default case), then the generated code for the "declawed" property of the Cat model looks like:
open class Cat: Animal {
public var declawed: Bool?
...
But when objcCompatible=true, then it looks like:
open class Cat: Animal {
public var declawed: Bool?
public var declawedNum: NSNumber? {
get {
return declawed.map({ return NSNumber(value: $0) })
}
}
...