Creating Custom Pickers

File Picker offers many ways to create custom pickers and assign them to your own models.

The FilePickerBase Class

The base file picker class has a mixture of class based views and helper functions for building the colorbox on the page. File pickers should be included in the file_pickers.py file in the root directory of any app so that the auto-discovery process can find it.

Attributes

Each picker can take a set of attributes for easy customization.:

from myapp.models import CustomModel
from myapp.forms import CustomForm
import file_pickers

class CustomPicker(file_picker.FilePickerBase):
    form = CustomForm
    page_size = 4
    link_headers = ['Insert File',]
    columns = ['name', 'body', 'description',]
    extra_headers = ['Name', 'Body', 'Description',]
    ordering = '-date'

file_picker.site.register(CustomModel, CustomPicker, name='custom')

None of these attributes are required and they all have sane defaults.

• form- If not set, a ModelForm is created using the model defined in the register function. This is used to build the form on the Upload tab.
• link_headers- Defines the headers for the first set of columns which are used to insert content into the textbox or WYSIWYG widget of your choice. By default, it converts _ to ‘ ‘ and capitalizes the first letter of the field’s name.
• columns- Defines the fields you want to be included on the listing page and their ordering.
• extra_headers- This list is used to display the headers for the columns and needs to be in the same order as columns.
• ordering- Defines the order of items on the listing page. In this example, the code would run query_set.order_by('-date'). If no ordering is provided, we’ll order by -pk.

Methods

The three main methods consist of append, list, and upload_file. List and upload_file take a request object and act as views, while append takes a model instance and builds the JSON output for list. Other methods are available but typically do not need to be modified.

append(obj)

This method takes obj which is a model instance and returns a dictionary to be used by list. This dictionary is of the form:

{
    'name': 'Name for the object.',
    'url': 'The url to the file.',
    'extra': {
        'column_name_1': 'value',
        'column_name_2': 'value',
    },
    'insert': [
        'text or html to insert if first link is clicked',
        'text or html to insert if second link is clicked',
    ],
    'link_content': [
        'string to show on first insert link',
        'string to show on second insert link',
    ],
}

The link_content list, insert list, and extra dictionary must all be the same length, and must match the length of the link_headers of your custom FilePicker.

list(request)

This takes a request object and returns:

{
    'page': 1-based integer representing current page number,
    'pages': List of pages,
    'search': The current search term,
    'result': List returned from *append*,
    'has_next': Boolean telling paginator whether to show the next button,
    'has_previous': Boolean telling paginator whether to show the previous button.,
    'link_headers': List of link headers defined by the Picker attribute (or generated if not defined),
    'extra_headers': List of the extra_headers specified by the Picker attribute,
    'columns': List of column names specified by the Picker attribute,
}

upload_file(request)

This takes a request object and builds the upload file form, which is used to upload files in two steps: first the file, and then the other form parameters.

If called without POST data it returns a JSON dictionary with the key form containing the HTML representation of the form.

If called with a file and then with the POST data, it performs a two step process. If the form validates successfully on the second step it returns the result of append for the object which was just created.