Remove undocumented tag property

app/lib/api/api.dart

@@ -728,20 +728,21 @@ class ApiOcsFilesSharingSharees {
 class ApiSystemtags {
   const ApiSystemtags(this.api);
 
+  /// Retrieve a list of all tags
+  ///
+  /// See: https://doc.owncloud.com/server/10.10/developer_manual/webdav_api/tags.html#list-tags
   Future<Response> propfind({
     id,
     displayName,
     userVisible,
     userAssignable,
-    canAssign,
   }) async {
     const endpoint = "remote.php/dav/systemtags";
     try {
       if (id == null &&
           displayName == null &&
           userVisible == null &&
-          userAssignable == null &&
-          canAssign == null) {
+          userAssignable == null) {
         // no body
         return await api.request("PROPFIND", endpoint);
       }
@@ -767,9 +768,6 @@ class ApiSystemtags {
             if (userAssignable != null) {
               builder.element("oc:user-assignable");
             }
-            if (canAssign != null) {
-              builder.element("oc:can-assign");
-            }
           });
         });
       return await api.request(
@@ -803,9 +801,9 @@ class ApiSystemtagsRelations {
 class ApiSystemtagsRelationsFiles {
   const ApiSystemtagsRelationsFiles(this.systemtagsRelations, this.fileId);
 
-  /// List systemtags associated with a file
+  /// Retrieve the tag ids and metadata of a given file
   ///
-  /// Warning: this Nextcloud API is undocumented
+  /// See: https://doc.owncloud.com/server/10.10/developer_manual/webdav_api/tags.html#retrieve-the-tag-ids-and-metadata-of-a-given-file
   Future<Response> propfind({
     id,
     displayName,

app/lib/entity/tag.dart

@@ -11,7 +11,6 @@ class Tag with EquatableMixin {
     required this.displayName,
     this.userVisible,
     this.userAssignable,
-    this.canAssign,
   });
 
   factory Tag.fromJson(JsonObj json) => Tag(
@@ -19,7 +18,6 @@ class Tag with EquatableMixin {
         displayName: json["displayName"],
         userVisible: json_util.boolFromJson(json["userVisible"]),
         userAssignable: json_util.boolFromJson(json["userAssignable"]),
-        canAssign: json_util.boolFromJson(json["canAssign"]),
       );
 
   JsonObj toJson() => {
@@ -27,7 +25,6 @@ class Tag with EquatableMixin {
         "displayName": displayName,
         if (userVisible != null) "userVisible": userVisible,
         if (userAssignable != null) "userAssignable": userAssignable,
-        if (canAssign != null) "canAssign": canAssign,
       };
 
   @override
@@ -42,9 +39,6 @@ class Tag with EquatableMixin {
     if (userAssignable != null) {
       buffer.write("userAssignable: $userAssignable, ");
     }
-    if (canAssign != null) {
-      buffer.write("canAssign: $canAssign, ");
-    }
     buffer.write("}");
     return buffer.toString();
   }
@@ -54,7 +48,6 @@ class Tag with EquatableMixin {
     String? displayName,
     OrNull<bool>? userVisible,
     OrNull<bool>? userAssignable,
-    OrNull<bool>? canAssign,
   }) =>
       Tag(
         id: id ?? this.id,
@@ -62,7 +55,6 @@ class Tag with EquatableMixin {
         userVisible: userVisible == null ? this.userVisible : userVisible.obj,
         userAssignable:
             userAssignable == null ? this.userAssignable : userAssignable.obj,
-        canAssign: canAssign == null ? this.canAssign : canAssign.obj,
       );
 
   @override
@@ -71,14 +63,12 @@ class Tag with EquatableMixin {
         displayName,
         userVisible,
         userAssignable,
-        canAssign,
       ];
 
   final int id;
   final String displayName;
   final bool? userVisible;
   final bool? userAssignable;
-  final bool? canAssign;
 }
 
 extension TagExtension on Tag {

app/lib/entity/tag/data_source.dart

@@ -18,7 +18,6 @@ class TagRemoteDataSource implements TagDataSource {
           displayName: 1,
           userVisible: 1,
           userAssignable: 1,
-          canAssign: 1,
         );
     if (!response.isGood) {
       _log.severe("[list] Failed requesting server: $response");
@@ -41,7 +40,6 @@ class TagRemoteDataSource implements TagDataSource {
               displayName: 1,
               userVisible: 1,
               userAssignable: 1,
-              canAssign: 1,
             );
     if (!response.isGood) {
       _log.severe("[listByFile] Failed requesting server: $response");

app/lib/entity/webdav_response_parser.dart

@@ -205,7 +205,6 @@ class WebdavResponseParser {
     String? displayName;
     bool? userVisible;
     bool? userAssignable;
-    bool? canAssign;
 
     for (final child in element.children.whereType<XmlElement>()) {
       if (child.matchQualifiedName("href",
@@ -231,7 +230,6 @@ class WebdavResponseParser {
         displayName = propParser.displayName;
         userVisible = propParser.userVisible;
         userAssignable = propParser.userAssignable;
-        canAssign = propParser.canAssign;
       }
     }
     if (id == null) {
@@ -244,7 +242,6 @@ class WebdavResponseParser {
       displayName: displayName!,
       userVisible: userVisible!,
       userAssignable: userAssignable!,
-      canAssign: canAssign!,
     );
   }
 
@@ -470,9 +467,6 @@ class _TagPropParser {
       } else if (child.matchQualifiedName("user-assignable",
           prefix: "http://owncloud.org/ns", namespaces: namespaces)) {
         _userAssignable = child.innerText == "true";
-      } else if (child.matchQualifiedName("can-assign",
-          prefix: "http://owncloud.org/ns", namespaces: namespaces)) {
-        _canAssign = child.innerText == "true";
       }
     }
   }
@@ -481,7 +475,6 @@ class _TagPropParser {
   String? get displayName => _displayName;
   bool? get userVisible => _userVisible;
   bool? get userAssignable => _userAssignable;
-  bool? get canAssign => _canAssign;
 
   final Map<String, String> namespaces;
 
@@ -492,7 +485,6 @@ class _TagPropParser {
   String? _displayName;
   bool? _userVisible;
   bool? _userAssignable;
-  bool? _canAssign;
 }
 
 extension on XmlElement {