# Simple-PyDI
## Intro
simple python dependency injection framwork
just like java spring-framework.
## Install
```shell script
pip install simple-pydi
```
## Usage
### Components
app.py
``` python
class Engine:
pass
class Wheels:
def __init__(self, wheels_count: int = 4):
self.wheels_count = wheels_count
class Body:
pass
class Person:
def __init__(self, name: str):
self.name = name
class Car:
def __init__(self, engine: Engine, wheels: Wheels, body: Body, driver: Person):
self.engine = engine
self.wheels = wheels
self.body = body
self.driver = driver
```
### Direct Register
main.py
```python
from di import NewContext
from app import Car, Engine, Wheels, Body, Person
ctx = NewContext()
# directly register beans
ctx.register(Car, id='car')
ctx.register(Engine)
ctx.register(Wheels)
ctx.register(Body)
ctx.register(Person, consts={'name': 'Ben'})
car: Car = ctx.instance_by_id('car')
assert car.driver.name == 'Ben'
assert car.wheels.wheels_count == 4
# view beans xml definition
print(ctx.format_beans_xml())
```
### Register by XML File
beans.xml
```xml
<?xml version="1.0" ?>
<beans>
<bean cls="app.Car" id="car" singleton="true">
<property name="engine" ref="cls:app.Engine"/>
<property name="wheels" ref="cls:app.Wheels"/>
<property name="body" ref="cls:app.Body"/>
<property name="driver" ref="cls:app.Person"/>
</bean>
<bean cls="app.Engine" id="app.Engine" singleton="true"/>
<bean cls="app.Wheels" id="app.Wheels" singleton="true">
<property name="wheels_count" value="4" value-type="int"/>
</bean>
<bean cls="app.Body" id="app.Body" singleton="true"/>
<bean cls="app.Person" id="app.Person" singleton="true">
<property name="name" value="Ben" value-type="str"/>
</bean>
</beans>
```
main.py
```python
from di import NewContext
from app import Car
ctx = NewContext()
# get beans definition from xml file
ctx.register_file('beans.xml')
car: Car = ctx.instance_by_id('car')
assert car.driver.name == 'Ben'
assert car.wheels.wheels_count == 4
# view beans xml definition
print(ctx.format_beans_xml())
```
### Use Decorator Definition
app.py
```python
from di.decorator import bean
@bean
class Engine:
pass
@bean
class Wheels:
def __init__(self, wheels_count: int = 4):
self.wheels_count = wheels_count
@bean
class Body:
pass
@bean(consts={'name': 'Ben'})
class Person:
def __init__(self, name: str):
self.name = name
@bean(id='car')
class Car:
def __init__(self, engine: Engine, wheels: Wheels, body: Body, driver: Person):
self.engine = engine
self.wheels = wheels
self.body = body
self.driver = driver
```
main.py
```python
from di import NewContext
from app import Car
ctx = NewContext()
# register pre defined group (by decorator)
ctx.register_group()
car: Car = ctx.instance_by_cls(Car)
assert car.driver.name == 'Ben'
assert car.wheels.wheels_count == 4
# view beans xml definition
print(ctx.format_beans_xml())
```
