The core portion of the Builder pattern concerns the Abstract Builder and its subclasses (concrete builders). According to GoF’s Design Patterns, director simply “notifies the builder whenever a part of the product should be built”, which can be perfectly done by the client. The StringBuilder class in the Java API is an example of a … Read more
You may want to look at lombok annotations to generate builders without the boiler plate code. For example: @Builder public class MyPojo { private String name; } MyPojoBuilder.builder().name(“yourame”).build(); The limitation is that this doesn’t seem to work with abstract classes.
If you wanted to avoid an eval(), you could just do: id = “1234asdf” constructor = globals()[id] instance = constructor() Provided that the class is defined in (or imported into) your current scope.
What I’d do is have NinjaBuilder keep the operations as a list of delegates, rather than applying them, and only apply them when .Build is called. This would allow you to make them conditional: public class NinjaBuilder { List<Action<Ninja>> builderActions = new List<Action<Ninja>>(); public Ninja Build() { var ninja = new Ninja(); builderActions.ForEach(ba => ba(ninja)); … Read more
Using Nokogiri::XML::Reader works for your example, but probably isn’t the full answer you are looking for (Note that there is no attributes method for Builder). reader = Nokogiri::XML::Reader(builder.to_xml) reader.read #Moves to next node in document reader.attribute(“messageId”) Note that if you issued reader.read again and then tried reader.attribute(“messageId”) the result will be nil since the current … Read more
To cause the keyboard to show up immediately you’ll need to set the text field as the first responder using the following line: [textField becomeFirstResponder]; You may want to place this in the viewDidAppear: method.
This is certainly possible with the recursive bound, but the subtype builders need to also be generic, and you need a few interim abstract classes. It’s a little bit cumbersome, but it’s still easier than the non-generic version. /** * Extend this for Mammal subtype builders. */ abstract class GenericMammalBuilder<B extends GenericMammalBuilder<B>> { String sex; … Read more
You can use a Step Builder if you have many mandatory parameters. In short: you define an interface for every single mandatory parameter and a builder method returns the next mandatory builder interface or the builder itself for optional methods. The builder remains a single class which implements all the interfaces. interface StepB { StepBuilder … Read more
FutureBuilder removes boilerplate code. Let’s say you want to fetch some data from the backend on page launch and show a loader until data comes. Tasks for ListBuilder: Have two state variables, dataFromBackend and isLoadingFlag On launch, set isLoadingFlag = true, and based on this, show loader. Once data arrives, set data with what you … Read more
Yes, you can place @Builder on a constructor or static (factory) method, containing just the fields you want. Disclosure: I am a Lombok developer.