pyentity 0.2.1

py-entity
========

Basic Python Entities
----------------------

An entity is useful for preparing models for an API or view.

Allows view or API UI specific logic to be removed from models.

### Example

We have some object..

```python
class GeorgeWashington(object):
id = 1776
first_name = 'George'
last_name = 'Washington'
phone_number = '(202) 456-1111'
phone_number_private = True
email = 'prez1@whouse.gov'
accomplishments = ['president', 'general', 'quarter model', 'woodworking']
birthday = datetime.datetime(1732, 2, 22, 0, 0)
```

Converting this object to json would take a bit of work. We need to write
some kind of `to_dictionary` method, or a custom encoder. There will stil
probably be an issue with the `datetime` (not JSON-encodable) as well as
the fact that we want to conditionally include the `phone_number`, as long
as `phone_number_private` is not `True`.

Using an `Entity`:

```python
class UserEntity(pyentity.Entity):
_FIELDS_ = [
'id',
'name',
'phone_number',
'email',
'accomplishments',
'birthday',
]
_ALIAS_ = 'user'

def name(self):
return "%s %s" % (self.user.first_name, self.user.last_name)

def birthday(self):
return self.user.birthday.isoformat()

def phone_number(self):
if self.user.phone_number_private:
raise pyentity.SuppressField
return self.user.phone_number
```

Then,

```python
george_entity = UserEntity(GeorgeWashington())
print json.dumps(george_entity(), indent=2)
```

```javascript
{
"email": "prez1@whouse.gov",
"accomplishments": [
"president",
"general",
"quarter model",
"woodworking"
],
"id": 1776,
"birthday": "1732-02-22T00:00:00",
"name": "George Washington"
}
```

Somtimes, we want to have different views over the same data. One may be a detailed
description of an object, but some other may just be a summary. Entity inheritance helps here.

```python
class SummaryEntity(UserEntity):
_FIELDS_ = ['name', 'email']
```

Then,

```python
summary_entity = SummaryEntity(GeorgeWashington())
print json.dumps(summary_entity(), indent=2)
```

```javascript
{
"name": "George Washington",
"email": "prez1@whouse.gov"
}
```