Refact codelists into thesauri

[etj]

WIP

¿ complex enough to be a GNIP ?

Current status

ISO codelists

There are some ISO metadata elements that have their own classes in GeoNode, with a common model:

• RestrictionCodeType
• SpatialRepresentationType
• TopicCategory

All of them share the same model:

identifier = models.CharField(max_length=255, default="location")
description = models.TextField(default="")
gn_description = models.TextField("GeoNode description", default="", null=True)
is_choice = models.BooleanField(default=True)

while TopicCategory also has

fa_class = models.CharField(max_length=64, default="fa-times")

This model does not include localization, which is handled in the .po files.

Frequencies

Frequency field is defined as:

    maintenance_frequency = models.CharField(
        _("maintenance frequency"),
        max_length=255,
        choices=enumerations.UPDATE_FREQUENCIES,
        ...

UPDATE_FREQUENCIES is defined as:

UPDATE_FREQUENCIES = (
    ("unknown", _("frequency of maintenance for the data is not known")),
    ("continual", _("data is repeatedly and frequently updated")),
    ("notPlanned", _("there are no plans to update the data")),

and localization is performed via .po files:

msgid "frequency of maintenance for the data is not known"
msgstr "la frequenza di manutenzione dei dati non è nota"

msgid "data is repeatedly and frequently updated"
msgstr "i dati vengono ripetutamente e frequentemente aggiornati"

Licenses

class License(models.Model):
    identifier = models.CharField(max_length=255, editable=False)
    name = models.CharField(max_length=255)
    abbreviation = models.CharField(max_length=20, null=True, blank=True)
    description = models.TextField(null=True, blank=True)
    url = models.URLField(max_length=2000, null=True, blank=True)
    license_text = models.TextField(null=True, blank=True)

Proposal

We could refactor these info into well known thesauri: it would

• enable localization
• reduce the number of classes/tables

ThesaurusKeyword has an image field (see #11617 and #11622):

    image = models.CharField(max_length=512, help_text="A URL to an image", null=True, blank=True)