Small framework for creating Builders and entities
Small framework to create entities and Builders with Metaprogramming features in Python.
Metabuilder objective is to help to create Builders and instances or entities with validations easy and fast.
In order to create a new Builder just define a class extending from MetaBuilder class, and defining an stub class in any place you want. For eg.
from PyMetaBuilder import MetaBuilder #Stub Class to create instances from class Kite(object): pass class KiteBuilder(MetaBuilder): pass
from version 0.2.1 onwards you can define the class model with the method model_by_name, thus you don’t have to define a stub class in your code. For ex. calling model_by_name(‘Kite’) instead of model(Kite)
After that just initiate the superclass and start defining the properties you want KiteBuilder to have, for eg.
class KiteBuilder(MetaBuilder): def __init__(self): MetaBuilder.MetaBuilder.__init__(self) self.defineKite() def define_kite(self): #define the model klass to get instances from self.model(Kite) self.property("design",one_of=["Indoor","Water Kite","Kythoon"]) self.property("line_material",type=str) self.property("StringLength",type=int)
You can also define a property as a mandatory one, with the required method. In this way, when you set the builder with the respecting properties and try to get a new instance, the framework will check if the properties that you previously set as mandatory were set.
def define_kite(self): #define the model klass to get instances from self.model(Kite) self.property("StringLength",type=int) #code defining properties.... self.required("design")
Creating instances from a Builder
After you defined a builder and its properties, just set the parameters, if you want at this time and if they’re not mandatory and build an instance.
kiteBuilder=KiteBuilder() kiteBuilder.design="Indoor" kiteBuilder.StringLength=23 kite=kiteBuilder.build() #get a Kite instance
When you set a property that you previously defined, it’ll validate the value passed, given the fact that you have set it with validators, and will generate the appropriate exception when it fails.