builder-pattern

问题 In Java, you can use the builder pattern to provide a more readable means to instantiating a class with many parameters. In the builder pattern, one constructs a configuration object with methods to set named attributes, and then uses it to construct another object. What is the equivalent in Python? Is the best way to mimic the same implementation? 回答1: Design patterns can often be replaced with built-in language features. Your use case You say "I wanted to have a more readable "means" to

问题 I have a builder class which I am using in one of my project. Let's say I have metricA as builder based on below class. I need to make a new builder metricB based on metricA by cloning metricA so that metricB contains all the values which were already there in metricA . In the constructor of MetricHolder I am initializing some fields (which are not set directly) basis on fields that have been set already. clientTypeOrPayId - I am initializing this field. If payId is present, then I will set

问题 Hi I'm stuck with a problem. I want to implement the builder pattern to make creating my objects easier. The problem I face has to do with nested object. The object I would like to create has a list of other objects in it, and I don't really have an idea on how to tackle it. I want to be able to do the following (Simpler objects for example): Receipt RestaurantReceipt = new ReceiptBuilder() .withDate("value") .withName("value") .AddItem("value") .WithIngredients("value") .WithType("value")

问题 Foo foo = Foo.builder() .setColor(red) .setName("Fred") .setSize(42) .build(); So I know there is the following "Builder" solution for creating named parameters when calling a method. Although, this only seems to work with inner static classes as the builder or am I wrong? I had a look at some tutorials for builder pattern but they seem really complex for what im trying to do. Is there any way to keep the Foo class and Builder class separate while having the benefit of named parameters like

问题 I've been studying design patterns with a study group recently, and have come to understand that the builder pattern can be very useful for creating complex objects that are made up of many (potentially optional) parts. However, is there ever a point where the builder is doing too much? Let's say we have a class that has many many different combinations of objects, is there another pattern that may be better suited for that instead of making dozens of different builders? Is it possible to

问题 I know this question is asked many times but I just want to clear more on this. Can a builder pattern replace factory pattern. Yes Builder pattern create and return a complex object step by step and this can be done in factory pattern also. 回答1: They are both Creational patterns. So, not replace, just an alternative that's appropriate under some conditions. The nature of patterns is that they present solutions to common problems, it's quite reasonable that subtly different problems have

问题 Let's assume an object constructed using a builder pattern. This builder pattern would contain a build method focusing on fields validation and then on conversion to the targeted type. This validation could be implemented using: Either[FailureObject, TargetObject] type Try[TargetObject] (new feature from Scala 2.10) Validation[FailureObject, TargetObject] or ValidationNEL[FailureObject, TargetObject] from scalaz library I read that one of the main advantages of Validation over Either type is

问题 If I wanted to generate a "fluent builder" in IntelliJ anyone know where to edit the live template that is used in the Replace Constructor with Builder feature? The above mentioned feature will automatically build a Builder pattern object though with the common setAttribute naming convention instead of a more fluentlike naming pattern of .attribute or .withAttribute that I am looking for. Ultimately I would like to just be able to change a setting / template that would be used in rendering

问题 I'm trying to create a builder pattern in Javascript that uses private variables, while providing one public accessor ( fullName ) that returns a mashup of all the other properties. This question and answer suggests that I can use Object.defineProperty inside the person constructor in order to access private variables, but it doesn't work - instance.fullName is always undefined . How can I get this working so that the builder pattern variables remain private, but the public accessor has

问题 I've implemented a simple builder pattern - code below. The code executes and runs but every 'with..' method in the builder class displays a warning with 'Return value of the method is never used' public static class StreamParserBuilder{ //optional - have defaults: private long spanLimit1 = 2000L; private long spanLimit2 = 100000L; private long spanLimit3 = 3000000L; private String[] coordinates = {"L1", "R2"}; private String outputDirectory = System.getProperty("user.dir"); private boolean