Include API endpoints in OPTIONS metadata

InvenTree/InvenTree/metadata.py

@@ -1,24 +1,18 @@
-
 # -*- coding: utf-8 -*-
+
 from __future__ import unicode_literals
 
-from django.db import models
-
-from collections import OrderedDict
-
-from django.core.exceptions import PermissionDenied
-from django.http import Http404
-from django.utils.encoding import force_str
-
-from rest_framework import exceptions, serializers, fields
-from rest_framework.request import clone_request
-from rest_framework.utils.field_mapping import ClassLookupDict
+import logging
 
+from rest_framework import serializers
 from rest_framework.metadata import SimpleMetadata
 
 import users.models
 
 
+logger = logging.getLogger('inventree')
+
+
 class InvenTreeMetadata(SimpleMetadata):
     """
     Custom metadata class for the DRF API.
@@ -88,3 +82,31 @@ class InvenTreeMetadata(SimpleMetadata):
             pass
 
         return metadata
+
+    def get_field_info(self, field):
+        """
+        Given an instance of a serializer field, return a dictionary
+        of metadata about it.
+
+        We take the regular DRF metadata and add our own unique flavor
+        """
+
+        # Run super method first
+        field_info = super().get_field_info(field)
+
+        # Introspect writable related fields
+        if field_info['type'] == 'field' and not field_info['read_only']:
+            
+            # If the field is a PrimaryKeyRelatedField, we can extract the model from the queryset
+            if isinstance(field, serializers.PrimaryKeyRelatedField):
+                model = field.queryset.model
+            else:
+                logger.debug("Could not extract model for:", field_info['label'], '->', field)
+                model = None
+
+            if model:
+                # Mark this field as "related", and point to the URL where we can get the data!
+                field_info['type'] = 'related field'
+                field_info['api_url'] = model.get_api_url()
+
+        return field_info

InvenTree/templates/js/forms.js

@@ -213,6 +213,8 @@ function constructFormBody(url, fields, options={}) {
         }
     }
 
+    // Render selected fields
+
     for (var idx = 0; idx < field_names.length; idx++) {
 
         var name = field_names[idx];
@@ -242,6 +244,7 @@ function constructFormBody(url, fields, options={}) {
 
     modalSetTitle(modal, title);
 
+    // Insert generated form content
     $(modal).find('.modal-form-content').html(html);
 
     $(modal).modal('show');
@@ -434,8 +437,8 @@ function constructInput(name, parameters, options={}) {
         case 'choice':
             func = constructChoiceInput;
             break;
-        case 'field':
-            // TODO: foreign key field!
+        case 'related field':
+            func = constructRelatedFieldInput;
             break;
         default:
             // Unsupported field type!
@@ -597,6 +600,22 @@ function constructChoiceInput(name, parameters, options={}) {
 }
 
 
+/*
+ * Construct a "related field" input.
+ * This will create a "select" input which will then, (after form is loaded),
+ * be converted into a select2 input.
+ * This will then be served custom data from the API (as required)...
+ */
+function constructRelatedFieldInput(name, parameters, options={}) {
+
+    var html = `<select id='id_${name}' class='select form-control' name='${name}'></select>`;
+
+    // Don't load any options - they will be filled via an AJAX request
+
+    return html;
+}
+
+
 /*
  * Construct a 'help text' div based on the field parameters
  *