#18 File upload in certain folders

* refactors documents and file upload to be distributed into different subfolders, depending on the type of document (InterventionDocument, RevocationDocument, ...)
* refactors Document model into AbstractDocument
* subclasses RevocationDocument, InterventionDocument, COmpensationDocument, EmaDocument and EcoAccountDocument from AbstractDocument to provide proper functionality for each
* adds new specialized routes for each new document type (opening, removing)
* drops generic get and remove routes for documents

konova/utils/documents.py

@@ -0,0 +1,50 @@
+"""
+Author: Michel Peltriaux
+Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
+Contact: michel.peltriaux@sgdnord.rlp.de
+Created on: 01.09.21
+
+"""
+from django.http import FileResponse, HttpRequest
+from django.utils.translation import gettext_lazy as _
+
+from konova.forms import RemoveModalForm
+from konova.models import AbstractDocument
+
+
+def get_document(doc: AbstractDocument):
+    """ Returns a document as downloadable attachment
+
+    Args:
+        request (HttpRequest): The incoming request
+        id (str): The document id
+
+    Returns:
+
+    """
+    return FileResponse(doc.file, as_attachment=True)
+
+
+def remove_document(request: HttpRequest, doc: AbstractDocument):
+    """ Renders a form for uploading new documents
+
+    This function works using a modal. We are not using the regular way, the django bootstrap modal forms are
+    intended to be used. Instead of View classes we work using the classic way of dealing with forms (see below).
+    It is important to mention, that modal forms, which should reload the page afterwards, must provide a
+    'reload_page' bool in the context. This way, the modal may reload the page or not.
+
+    For further details see the comments in templates/modal or
+    https://github.com/trco/django-bootstrap-modal-forms
+
+    Args:
+        request (HttpRequest): The incoming request
+
+    Returns:
+
+    """
+    title = doc.title
+    form = RemoveModalForm(request.POST or None, instance=doc, user=request.user)
+    return form.process_request(
+        request=request,
+        msg_success=_("Document '{}' deleted").format(title)
+    )