Extending the order import process

It’s possible through the backend to import orders into eventyay, for example from a legacy ticketing system. If your plugins defines additional data structures around orders, it might be useful to make it possible to import them as well.

Import process

Here’s a short description of eventyay’ import process to show you where the system will need to interact with your plugin. You can find more detailed descriptions of the attributes and methods further below.

  1. The user uploads a CSV file. The system tries to parse the CSV file and understand its column headers.

  2. A preview of the file is shown to the user and the user is asked to assign the various different input parameters to columns of the file or static values. For example, the user either needs to manually select a product or specify a column that contains a product. For this purpose, a select field is rendered for every possible input column, allowing the user to choose between a default/empty value (defined by your default_value/default_label) attributes, the columns of the uploaded file, or a static value (defined by your static_choices method).

  3. The user submits its assignment and the system uses the resolve method of all columns to get the raw value for all columns.

  4. The system uses the clean method of all columns to verify that all input fields are valid and transformed to the correct data type.

  5. The system prepares internal model objects (Order etc) and uses the assign method of all columns to assign these objects with actual values.

  6. The system saves all of these model objects to the database in a database transaction. Plugins can create additional objects in this stage through their save method.

Column registration

The import API does not make a lot of usage from signals, however, it does use a signal to get a list of all available import columns. Your plugin should listen for this signal and return the subclass of eventyay.base.orderimport.ImportColumn that we’ll provide in this plugin:

 1from django.dispatch import receiver
 2
 3from eventyay.base.signals import order_import_columns
 4
 5
 6@receiver(order_import_columns, dispatch_uid="custom_columns")
 7def register_column(sender, **kwargs):
 8    return [
 9        EmailColumn(sender),
10    ]

The column class API

class eventyay.base.orderimport.ImportColumn

The central object of each import extension is the subclass of ImportColumn.

ImportColumn.event

The default constructor sets this property to the event we are currently working for.

identifier

Unique, internal name of the column.

This is an abstract attribute, you must override this!

verbose_name

Human-readable description of the column.

This is an abstract attribute, you must override this!

default_value

Internal default value for the assignment of this column. Defaults to empty. Return None to disable this option.

default_label

Human-readable description of the default assignment of this column, defaults to “Keep empty”.

initial

Initial value for the form component.

static_choices()

This will be called when rendering the form component and allows you to return a list of values that can be selected by the user statically during import.

Returns:

list of 2-tuples of strings

resolve(settings, record)

This method will be called to get the raw value for this field, usually by either using a static value or inspecting the CSV file for the assigned header.

clean(value, previous_values)

Allows you to validate the raw input value for your column. Raise ValidationError if the value is invalid.

Parameters:

  • value – The raw value of your column as returned by resolve.

  • previous_values – Dictionary containing the validated values of all columns that have already been validated.

assign(value, order, position, invoice_address, **kwargs)

This will be called to perform the actual import. Set attributes on the order, position, or invoice_address objects based on the input value.

save(order)

This will be called to perform the actual import inside the database transaction. The input object order has already been saved to the database.

Example

For example, the import column responsible for assigning email addresses looks like this:

 1class EmailColumn(ImportColumn):
 2    identifier = 'email'
 3    verbose_name = _('E-mail address')
 4
 5    def clean(self, value, previous_values):
 6        if value:
 7            EmailValidator()(value)
 8        return value
 9
10    def assign(self, value, order, position, invoice_address, **kwargs):
11        order.email = value