Working on implementation of a related field

lib/api.dart

@@ -128,7 +128,13 @@ class InvenTreeAPI {
 
   String get imageUrl => _makeUrl("/image/");
 
-  String makeApiUrl(String endpoint) => _makeUrl("/api/" + endpoint);
+  String makeApiUrl(String endpoint) {
+    if (endpoint.startsWith("/api/") || endpoint.startsWith("api/")) {
+      return _makeUrl(endpoint);
+    } else {
+      return _makeUrl("/api/" + endpoint);
+    }
+  }
 
   String makeUrl(String endpoint) => _makeUrl(endpoint);
 

lib/api_form.dart

@@ -1,3 +1,4 @@
+import 'package:flutter_typeahead/flutter_typeahead.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:inventree/api.dart';
 import 'package:inventree/app_colors.dart';
@@ -26,6 +27,9 @@ class APIFormField {
   // JSON data which defines the field
   final dynamic data;
 
+  // Get the "api_url" associated with a related field
+  String get api_url => data["api_url"] ?? "";
+
   // Is this field hidden?
   bool get hidden => (data['hidden'] ?? false) as bool;
 
@@ -53,6 +57,9 @@ class APIFormField {
     return messages;
   }
 
+  // TODO
+  dynamic get filters => null;
+
   // Is this field required?
   bool get required => (data['required'] ?? false) as bool;
 
@@ -72,13 +79,32 @@ class APIFormField {
         return _constructString();
       case "boolean":
         return _constructBoolean();
+      case "related field":
+        return _constructRelatedField();
       default:
         return ListTile(
-          title: Text("Unsupported field type: '${type}'")
+          title: Text(
+            "Unsupported field type: '${type}'",
+            style: TextStyle(
+                color: COLOR_DANGER,
+                fontStyle: FontStyle.italic),
+          )
         );
     }
   }
 
+  // Construct an input for a related field
+  Widget _constructRelatedField() {
+
+    return AutocompleteFormField(
+      required ? label + "*" : label,
+      api_url,
+      filters: filters,
+      hint: helpText,
+      renderer: null,
+    );
+  }
+
   // Consturct a string input element
   Widget _constructString() {
 

lib/widget/fields.dart

@@ -1,6 +1,8 @@
 
 import 'package:flutter/material.dart';
+import 'package:flutter_typeahead/flutter_typeahead.dart';
 import 'package:image_picker/image_picker.dart';
+import 'package:inventree/api.dart';
 
 import 'package:inventree/l10.dart';
 
@@ -115,6 +117,81 @@ class CheckBoxField extends FormField<bool> {
 }
 
 
+class AutocompleteFormField extends TypeAheadFormField {
+
+  final String label;
+
+  final _controller = TextEditingController();
+
+  final String url;
+
+  dynamic filters = {};
+
+  AutocompleteFormField(
+      this.label,
+      this.url,
+      {
+        this.filters,
+        Widget Function(dynamic)? renderer,
+        String? hint,
+      }) :
+      super(
+        textFieldConfiguration: TextFieldConfiguration(
+          autofocus: true,
+          decoration: InputDecoration(
+            hintText: hint,
+            border: OutlineInputBorder(),
+          ),
+        ),
+        suggestionsCallback: (String pattern) async {
+
+          Map<String, String> _filters = {};
+
+          if (filters != null) {
+            for (String key in filters) {
+              _filters[key] = filters[key].toString();
+            }
+          }
+
+          _filters["search"] = pattern;
+          _filters["offset"] = "0";
+          _filters["limit"] = "25";
+
+          final APIResponse response = await InvenTreeAPI().get(
+            url,
+            params: _filters
+          );
+
+          if (response.isValid()) {
+
+            List<dynamic> results = [];
+
+            for (var result in response.data['results'] ?? []) {
+              results.add(result);
+            }
+
+            return results;
+          } else {
+            return [];
+          }
+
+        },
+        itemBuilder: (context, suggestion) {
+          print("item builder: " + suggestion.toString());
+          return ListTile(
+            title: Text(suggestion['name']),
+          );
+        },
+        onSuggestionSelected: (suggestion) {
+          // TODO
+        },
+        onSaved: (value) {
+          // TODO
+        }
+      );
+}
+
+
 class StringField extends TextFormField {
 
   StringField({String label = "", String? hint, String? initial, Function(String?)? onSaved, Function? validator, bool allowEmpty = false, bool isEnabled = true}) :

lib/widget/part_detail.dart

@@ -187,6 +187,8 @@ class _PartDisplayState extends RefreshableState<PartDetailWidget> {
           "keywords": {},
           "link": {},
 
+          "category": {},
+
           // Checkbox fields
           "active": {},
           "assembly": {},