lostplaces-backend/django_lostplaces/docs/developer.md

# django lostplaces documentation for developer

Greetings,
this documentation is for anyone who wants to work with this projects codebase or is just curious about how it works.


## Models
The models contain an custom user profile, some abstract base models and the models holding the actual data for this project


### Explorer user profile
Location: `lostplaces.models.models.Explorer`  
Import from: `lostplaces.models.Explorer`
#### Super Classes
- django's `models.Model`

The class `lostplaces.models.Explorer` is our custom user profile. It has an ForeignKey pointing at django's default user model instead of providing an entire custom user model. That way this django app does not conflict with any other app that brings it's own user model.

You can access the explorer profile by accessing the 'explorer' attribute of any user instance
```python
user.explorer
```

Currently the explorer profile is used by the abstract model 'Submittable' and has the following realated names/fiels:
- [places](###place) A list containing all (lost) places the user has submitted  
- [placeimages](###placeimages) A list containing all images relating a place that a user has submitted
- [externallinks](###externallinks) A list of all photo albums a explorere has submitted


### Taggable
Location: `lostplaces.models.abstract_models.Taggable`  
Import from: `lostplaces.models.Taggable`
#### Super Classes
- django's `models.Model`

The abstract model Taggable represents an model that is taggable. It depends on the django app [taggit](https://github.com/jazzband/django-taggit). It only consists of one field:  
- `tag`: TaggableManager, allows the sub class to be tagged, blank=True allows the admin form to be submitted without any tags


### Mapable
Location: `lostplaces.models.abstract_models.Mapable`  
Import from: `lostplaces.models.Mapable`
#### Super Classes
- django's `models.Model`

The abstract model Mapable represents an model that can be displayed on a map. It consists of tree attributes  
`name`  
Name of the object, displayed on the map, max length 50 characters  
`latitude`  
Latitude of the referenced location, -90 <= value <= 90  
`longitude`  
Longitude of the referenced location  -180 <= value <= 180  
A mapable model has to provide its own get_absolute_url, in order to provide a link when clicked.


### Submittable
Location: `lostplaces.models.abstract_models.Submittable`  
Import from: `lostplaces.models.Submittable`
#### Super Classes
- django's `models.Model`

The abstract model Submittable represents an model that can be submitted by an user. It knows who submitted something and when:  
`submitted_by`  
Referencing the explorer profile, see [Explorer](##explorer-user-profile). If the explorer profile is deleted, this instance is kept (on_delete=models.SET_NULL). The related_name is set to the class name, lower case appending an s (%(class)ss)  
`submitted_when`  
When the object was submitted, automatically set by django (auto_now_add=True)

### Expireable
Location: `lostplaces.models.abstract_models.Expireable`  
Import from: `lostplaces.models.Expireable`
#### Super Classes
- django's `models.Model`

This abstract model represents an object that can expire. It is currently used by the Voucher model. I consists of two fields:
`created_when`  
The date the object was created, automatically set by django (auto_now_add=True)  
`expires_when`  
The date the object expires.

### Voucher
Locatoin: `lostplaces.models.Voucher`  
Import from: `lostplaces.models.Voucher`
#### Super Classes
- django's `models.Model`
- [lostplaces.models.Expireable](###expireable)

A voucher code is needed to sign up using lostplaces sign up form. The model contains  
`code`  
The voucher code, max length 30 characters
`created_when`  
When the voucher was created automatically set by django (auto_now_add=True)  
`expires_when`  
Till what date the voucher remains valid


### Place
Location: `lostplaces.models.place.Place`  
Import from: `lostplaces.models.Place`
#### Super Classes
- django's `models.Model`
- [lostplaces.models.Submittable](###submittable)-
- [lostplaces.models.Taggable](###taggable)
- [lostlaces.models.Mapable]

The place model is the heart of this project. It stores all information about a place needed.  
`location`  
Human readable location description (town, village, street), max length 50 characters  
`description`  
Describing the place in detail  
The place model uses these abstract super classes
- Submittable, see [Submittable](##submittable) for additional fields
- Taggable, see [Taggable](##taggable) for additional fields
- Mapable, see [Mapable](##mapable) for additional fields
The average_latlon function takes a list of places and returns the center point of all these places.

### PlaceAsset
Location: `lostplaces.models.PlaceAsset`  
Import from: `lostplaces.models.place.PlaceAsset`
#### Super Classes
- django's `models.Model`
- [lostplaces.models.Submittable](###submittable)

A PlaceAsset is anything that belongs to a place. The PlaceImage model for exmpaple is a subclass of PlaceAsset. A PlaceAsset is supposed to be submittable by every user. Only the user who has submitted the asset, the place the asset belongs to or both can delete a asset.

An PlaceAsset has the following fields
`place`  
The Place this PlaceAsset belongs to

The PlaceAsset model is a subclass of Submittable, see [Submittable](###submittable) for more details.

### External Link
Loacation: `lostplaces.models.external_link.ExternalLink`  
Import From: `lostplaces.models.ExternalLink`
#### Super Classes
- django's `models.Model`
- [lostplaces.models.Submittable](###submittable)
- [lostplaces.models.PlaceAsset](###placeasset)

This model represents an URL to an external website. External Link is an PlaceAsset, see [above](###placeasset) for more details. External Link has to fields
`url`  
the URL to the target
`label`  
the label that is shown on the website