Modern attachments (#505)

* Minimum API version is now 100

* Remove old API features

- Anything below API v100 no longer supported

* Reefactor attachment widget to support modern attachment API

* Filter and display attachments correctly

* Refactor

lib/inventree/company.dart

@@ -106,7 +106,10 @@ class InvenTreeCompanyAttachment extends InvenTreeAttachment {
   String get REFERENCE_FIELD => "company";
 
   @override
-  String get URL => "company/attachment/";
+  String get REF_MODEL_TYPE => "company";
+
+  @override
+  String get URL => InvenTreeAPI().supportsModernAttachments ? "attachment/" : "company/attachment/";
 
   @override
   InvenTreeModel createFromJson(Map<String, dynamic> json) => InvenTreeCompanyAttachment.fromJson(json);

lib/inventree/model.dart

@@ -938,9 +938,17 @@ class InvenTreeAttachment extends InvenTreeModel {
 
   InvenTreeAttachment.fromJson(Map<String, dynamic> json) : super.fromJson(json);
 
+  @override
+  String get URL => "attachment/";
+
   // Override this reference field for any subclasses
+  // Note: This is used for the *legacy* attachment API
   String get REFERENCE_FIELD => "";
 
+  // Override this reference field for any subclasses
+  // Note: This is used for the *modern* attachment API
+  String get REF_MODEL_TYPE => "";
+
   String get attachment => getString("attachment");
   
   // Return the filename of the attachment
@@ -989,15 +997,39 @@ class InvenTreeAttachment extends InvenTreeModel {
     }
   }
 
-  Future<bool> uploadAttachment(File attachment, int parentId, {String comment = "", Map<String, String> fields = const {}}) async {
+  // Return a count of how many attachments exist against the specified model ID
+  Future<int> countAttachments(int modelId) {
+
+    Map<String, String> filters = {};
+
+    if (InvenTreeAPI().supportsModernAttachments) {
+      filters["model_type"] = REF_MODEL_TYPE;
+      filters["model_id"] = modelId.toString();
+    } else {
+      filters[REFERENCE_FIELD] = modelId.toString();
+    }
+
+    return count(filters: filters);
+  }
+
+  Future<bool> uploadAttachment(File attachment, String modelType, int modelId, {String comment = "", Map<String, String> fields = const {}}) async {
 
     // Ensure that the correct reference field is set
     Map<String, String> data = Map<String, String>.from(fields);
 
-    data[REFERENCE_FIELD] = parentId.toString();
+    String url = URL;
+
+    if (InvenTreeAPI().supportsModernAttachments) {
+      // All attachments are stored in a consolidated table
+      url = "attachment/";
+      data["model_id"] = modelId.toString();
+      data["model_type"] = modelType;
+    } else {
+      data[REFERENCE_FIELD] = modelId.toString();
+    }
 
     final APIResponse response = await InvenTreeAPI().uploadFile(
-        URL,
+        url,
         attachment,
         method: "POST",
         name: "attachment",

lib/inventree/part.dart

@@ -36,10 +36,6 @@ class InvenTreePartCategory extends InvenTreeModel {
       "structural": {},
     };
 
-    if (!api.supportsStructuralCategories) {
-      fields.remove("structural");
-    }
-
     return fields;
   }
 
@@ -475,7 +471,10 @@ class InvenTreePartAttachment extends InvenTreeAttachment {
   String get REFERENCE_FIELD => "part";
 
   @override
-  String get URL => "part/attachment/";
+  String get REF_MODEL_TYPE => "part";
+
+  @override
+  String get URL => InvenTreeAPI().supportsModernAttachments ? "attachment/" : "part/attachment/";
 
   @override
   InvenTreeModel createFromJson(Map<String, dynamic> json) => InvenTreePartAttachment.fromJson(json);

lib/inventree/purchase_order.dart

@@ -237,7 +237,10 @@ class InvenTreePurchaseOrderAttachment extends InvenTreeAttachment {
   String get REFERENCE_FIELD => "order";
 
   @override
-  String get URL => "order/po/attachment/";
+  String get REF_MODEL_TYPE => "purchaseorder";
+
+  @override
+  String get URL => InvenTreeAPI().supportsModernAttachments ? "attachment/" : "order/po/attachment/";
 
   @override
   InvenTreeModel createFromJson(Map<String, dynamic> json) => InvenTreePurchaseOrderAttachment.fromJson(json);

lib/inventree/sales_order.dart

@@ -280,6 +280,9 @@ class InvenTreeSalesOrderAttachment extends InvenTreeAttachment {
   String get REFERENCE_FIELD => "order";
 
   @override
-  String get URL => "order/so/attachment/";
+  String get REF_MODEL_TYPE => "salesorder";
+
+  @override
+  String get URL => InvenTreeAPI().supportsModernAttachments ? "attachment/" : "order/so/attachment/";
 
 }

lib/inventree/stock.dart

@@ -635,11 +635,13 @@ class InvenTreeStockItemAttachment extends InvenTreeAttachment {
   String get REFERENCE_FIELD => "stock_item";
 
   @override
-  String get URL => "stock/attachment/";
+  String get REF_MODEL_TYPE => "stockitem";
+
+  @override
+  String get URL => InvenTreeAPI().supportsModernAttachments ? "attachment/" : "stock/attachment/";
 
   @override
   InvenTreeModel createFromJson(Map<String, dynamic> json) => InvenTreeStockItemAttachment.fromJson(json);
-
 }
 
 
@@ -669,10 +671,6 @@ class InvenTreeStockLocation extends InvenTreeModel {
       "structural": {},
     };
 
-    if (!api.supportsStructuralCategories) {
-      fields.remove("structural");
-    }
-
     return fields;
   }