Umbraco-CMS/src/Umbraco.Web.BackOffice/Trees/ContentTreeControllerBase.cs

using System.Collections.Concurrent;
using System.Globalization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Umbraco.Cms.Core;
using Umbraco.Cms.Core.Actions;
using Umbraco.Cms.Core.Cache;
using Umbraco.Cms.Core.Events;
using Umbraco.Cms.Core.Models;
using Umbraco.Cms.Core.Models.Entities;
using Umbraco.Cms.Core.Models.Trees;
using Umbraco.Cms.Core.Security;
using Umbraco.Cms.Core.Services;
using Umbraco.Cms.Core.Trees;
using Umbraco.Cms.Web.Common.ModelBinders;
using Umbraco.Extensions;

namespace Umbraco.Cms.Web.BackOffice.Trees;

public abstract class ContentTreeControllerBase : TreeController, ITreeNodeController
{
    private static readonly char[] Comma = { ',' };
    private readonly ActionCollection _actionCollection;
    private readonly AppCaches _appCaches;
    private readonly IBackOfficeSecurityAccessor _backofficeSecurityAccessor;
    private readonly IDataTypeService _dataTypeService;

    private readonly ConcurrentDictionary<string, IEntitySlim?> _entityCache = new();
    private readonly IEntityService _entityService;
    private readonly ILogger<ContentTreeControllerBase> _logger;
    private readonly IUserService _userService;

    private bool? _ignoreUserStartNodes;


    protected ContentTreeControllerBase(
        ILocalizedTextService localizedTextService,
        UmbracoApiControllerTypeCollection umbracoApiControllerTypeCollection,
        IMenuItemCollectionFactory menuItemCollectionFactory,
        IEntityService entityService,
        IBackOfficeSecurityAccessor backofficeSecurityAccessor,
        ILogger<ContentTreeControllerBase> logger,
        ActionCollection actionCollection,
        IUserService userService,
        IDataTypeService dataTypeService,
        IEventAggregator eventAggregator,
        AppCaches appCaches)
        : base(localizedTextService, umbracoApiControllerTypeCollection, eventAggregator)
    {
        _entityService = entityService;
        _backofficeSecurityAccessor = backofficeSecurityAccessor;
        _logger = logger;
        _actionCollection = actionCollection;
        _userService = userService;
        _dataTypeService = dataTypeService;
        _appCaches = appCaches;
        MenuItemCollectionFactory = menuItemCollectionFactory;
    }

    public IMenuItemCollectionFactory MenuItemCollectionFactory { get; }

    /// <summary>
    ///     Returns the
    /// </summary>
    protected abstract int RecycleBinId { get; }

    /// <summary>
    ///     Returns true if the recycle bin has items in it
    /// </summary>
    protected abstract bool RecycleBinSmells { get; }

    /// <summary>
    ///     Returns the user's start node for this tree
    /// </summary>
    protected abstract int[] UserStartNodes { get; }

    protected abstract UmbracoObjectTypes UmbracoObjectType { get; }


    #region Actions

    /// <summary>
    ///     Gets an individual tree node
    /// </summary>
    /// <param name="id"></param>
    /// <param name="queryStrings"></param>
    /// <returns></returns>
    public ActionResult<TreeNode?> GetTreeNode([FromRoute] string id, [ModelBinder(typeof(HttpQueryStringModelBinder))] FormCollection? queryStrings)
    {
        Guid asGuid = Guid.Empty;
        if (int.TryParse(id, NumberStyles.Integer, CultureInfo.InvariantCulture, out int asInt) == false)
        {
            if (Guid.TryParse(id, out asGuid) == false)
            {
                return NotFound();
            }
        }

        IEntitySlim? entity = asGuid == Guid.Empty
            ? _entityService.Get(asInt, UmbracoObjectType)
            : _entityService.Get(asGuid, UmbracoObjectType);
        if (entity == null)
        {
            return NotFound();
        }

        TreeNode? node = GetSingleTreeNode(entity, entity.ParentId.ToInvariantString(), queryStrings);

        if (node is not null)
        {
            // Add the tree alias to the node since it is standalone (has no root for which this normally belongs)
            node.AdditionalData["treeAlias"] = TreeAlias;
        }

        return node;
    }

    #endregion

    /// <summary>
    ///     Ensure the noAccess metadata is applied for the root node if in dialog mode and the user doesn't have path access
    ///     to it
    /// </summary>
    /// <param name="queryStrings"></param>
    /// <returns></returns>
    protected override ActionResult<TreeNode?> CreateRootNode(FormCollection queryStrings)
    {
        ActionResult<TreeNode?> nodeResult = base.CreateRootNode(queryStrings);
        if (nodeResult.Result is null)
        {
            return nodeResult;
        }

        TreeNode? node = nodeResult.Value;

        if (node is not null && IsDialog(queryStrings) && UserStartNodes.Contains(Constants.System.Root) == false &&
            IgnoreUserStartNodes(queryStrings) == false)
        {
            node.AdditionalData["noAccess"] = true;
        }

        return node;
    }

    protected abstract TreeNode? GetSingleTreeNode(IEntitySlim entity, string parentId, FormCollection? queryStrings);

    /// <summary>
    ///     Returns a <see cref="TreeNode" /> for the <see cref="IUmbracoEntity" /> and
    ///     attaches some meta data to the node if the user doesn't have start node access to it when in dialog mode
    /// </summary>
    /// <param name="e"></param>
    /// <param name="parentId"></param>
    /// <param name="queryStrings"></param>
    /// <param name="startNodeIds"></param>
    /// <param name="startNodePaths"></param>
    /// <returns></returns>
    internal TreeNode? GetSingleTreeNodeWithAccessCheck(IEntitySlim e, string parentId, FormCollection queryStrings, int[]? startNodeIds, string[]? startNodePaths)
    {
        var entityIsAncestorOfStartNodes =
            ContentPermissions.IsInBranchOfStartNode(e.Path, startNodeIds, startNodePaths, out var hasPathAccess);
        var ignoreUserStartNodes = IgnoreUserStartNodes(queryStrings);
        if (ignoreUserStartNodes == false && entityIsAncestorOfStartNodes == false)
        {
            return null;
        }

        TreeNode? treeNode = GetSingleTreeNode(e, parentId, queryStrings);
        if (treeNode == null)
        {
            //this means that the user has NO access to this node via permissions! They at least need to have browse permissions to see
            //the node so we need to return null;
            return null;
        }

        if (!ignoreUserStartNodes && !hasPathAccess)
        {
            treeNode.AdditionalData["noAccess"] = true;
        }

        return treeNode;
    }

    private void GetUserStartNodes(out int[]? startNodeIds, out string[]? startNodePaths)
    {
        switch (RecycleBinId)
        {
            case Constants.System.RecycleBinMedia:
                startNodeIds =
                    _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.CalculateMediaStartNodeIds(
                        _entityService, _appCaches);
                startNodePaths =
                    _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.GetMediaStartNodePaths(_entityService, _appCaches);
                break;
            case Constants.System.RecycleBinContent:
                startNodeIds =
                    _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.CalculateContentStartNodeIds(
                        _entityService, _appCaches);
                startNodePaths =
                    _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.GetContentStartNodePaths(
                        _entityService, _appCaches);
                break;
            default:
                throw new NotSupportedException("Path access is only determined on content or media");
        }
    }

    protected virtual ActionResult<TreeNodeCollection> PerformGetTreeNodes(string id, FormCollection queryStrings)
    {
        var nodes = new TreeNodeCollection();

        var rootIdString = Constants.System.RootString;
        var hasAccessToRoot = UserStartNodes.Contains(Constants.System.Root);

        var startNodeId = queryStrings.HasKey(TreeQueryStringParameters.StartNodeId)
            ? queryStrings.GetValue<string>(TreeQueryStringParameters.StartNodeId)
            : string.Empty;

        var ignoreUserStartNodes = IgnoreUserStartNodes(queryStrings);

        if (string.IsNullOrEmpty(startNodeId) == false && startNodeId != "undefined" && startNodeId != rootIdString)
        {
            // request has been made to render from a specific, non-root, start node
            id = startNodeId;

            // ensure that the user has access to that node, otherwise return the empty tree nodes collection
            // TODO: in the future we could return a validation statement so we can have some UI to notify the user they don't have access
            if (ignoreUserStartNodes == false && HasPathAccess(id, queryStrings) == false)
            {
                _logger.LogWarning(
                    "User {Username} does not have access to node with id {Id}",
                    _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.Username,
                    id);
                return nodes;
            }

            // if the tree is rendered...
            // - in a dialog: render only the children of the specific start node, nothing to do
            // - in a section: if the current user's start nodes do not contain the root node, we need
            //   to include these start nodes in the tree too, to provide some context - i.e. change
            //   start node back to root node, and then GetChildEntities method will take care of the rest.
            if (IsDialog(queryStrings) == false && hasAccessToRoot == false)
            {
                id = rootIdString;
            }
        }

        // get child entities - if id is root, but user's start nodes do not contain the
        // root node, this returns the start nodes instead of root's children
        ActionResult<IEnumerable<IEntitySlim>> entitiesResult = GetChildEntities(id, queryStrings);
        if (!(entitiesResult.Result is null))
        {
            return entitiesResult.Result;
        }

        var entities = entitiesResult.Value?.ToList();

        //get the current user start node/paths
        GetUserStartNodes(out var userStartNodes, out var userStartNodePaths);

        // if the user does not have access to the root node, what we have is the start nodes,
        // but to provide some context we need to add their topmost nodes when they are not
        // topmost nodes themselves (level > 1).
        if (id == rootIdString && hasAccessToRoot == false)
        {
            // first add the entities that are topmost to the nodes collection
            IEntitySlim[]? topMostEntities = entities?.Where(x => x.Level == 1).ToArray();
            nodes.AddRange(
                topMostEntities?.Select(x =>
                        GetSingleTreeNodeWithAccessCheck(x, id, queryStrings, userStartNodes, userStartNodePaths))
                    .WhereNotNull() ?? Enumerable.Empty<TreeNode>());

            // now add the topmost nodes of the entities that aren't topmost to the nodes collection as well
            // - these will appear as "no-access" nodes in the tree, but will allow the editors to drill down through the tree
            //   until they reach their start nodes
            var topNodeIds = entities?.Except(topMostEntities ?? Enumerable.Empty<IEntitySlim>()).Select(GetTopNodeId)
                .Where(x => x != 0).Distinct().ToArray();
            if (topNodeIds?.Length > 0)
            {
                IEnumerable<IEntitySlim> topNodes = _entityService.GetAll(UmbracoObjectType, topNodeIds.ToArray());
                nodes.AddRange(topNodes.Select(x =>
                        GetSingleTreeNodeWithAccessCheck(x, id, queryStrings, userStartNodes, userStartNodePaths))
                    .WhereNotNull());
            }
        }
        else
        {
            // the user has access to the root, just add the entities
            nodes.AddRange(
                entities?.Select(x =>
                        GetSingleTreeNodeWithAccessCheck(x, id, queryStrings, userStartNodes, userStartNodePaths))
                    .WhereNotNull() ?? Enumerable.Empty<TreeNode>());
        }

        return nodes;
    }

    private int GetTopNodeId(IUmbracoEntity entity)
    {
        var parts = entity.Path.Split(Comma, StringSplitOptions.RemoveEmptyEntries);
        return parts.Length >= 2 && int.TryParse(parts[1], NumberStyles.Integer, CultureInfo.InvariantCulture, out int id)
            ? id
            : 0;
    }

    protected abstract ActionResult<MenuItemCollection> PerformGetMenuForNode(string id, FormCollection queryStrings);

    protected virtual ActionResult<IEnumerable<IEntitySlim>> GetChildEntities(string id, FormCollection queryStrings)
    {
        // try to parse id as an integer else use GetEntityFromId
        // which will grok Guids, Udis, etc and let use obtain the id
        if (!int.TryParse(id, NumberStyles.Integer, CultureInfo.InvariantCulture, out var entityId))
        {
            IEntitySlim? entity = GetEntityFromId(id);
            if (entity == null)
            {
                return NotFound();
            }

            entityId = entity.Id;
        }

        var ignoreUserStartNodes = IgnoreUserStartNodes(queryStrings);

        IEntitySlim[] result;

        // if a request is made for the root node but user has no access to
        // root node, return start nodes instead
        if (!ignoreUserStartNodes && entityId == Constants.System.Root &&
            UserStartNodes.Contains(Constants.System.Root) == false)
        {
            result = UserStartNodes.Length > 0
                ? _entityService.GetAll(UmbracoObjectType, UserStartNodes).ToArray()
                : Array.Empty<IEntitySlim>();
        }
        else
        {
            result = GetChildrenFromEntityService(entityId).ToArray();
        }

        return result;
    }

    private IEnumerable<IEntitySlim> GetChildrenFromEntityService(int entityId)
        => _entityService.GetChildren(entityId, UmbracoObjectType).ToList();

    /// <summary>
    ///     Returns true or false if the current user has access to the node based on the user's allowed start node (path)
    ///     access
    /// </summary>
    /// <param name="id"></param>
    /// <param name="queryStrings"></param>
    /// <returns></returns>
    //we should remove this in v8, it's now here for backwards compat only
    protected abstract bool HasPathAccess(string id, FormCollection queryStrings);

    /// <summary>
    ///     Returns true or false if the current user has access to the node based on the user's allowed start node (path)
    ///     access
    /// </summary>
    /// <param name="entity"></param>
    /// <param name="queryStrings"></param>
    /// <returns></returns>
    protected bool HasPathAccess(IUmbracoEntity? entity, FormCollection queryStrings)
    {
        if (entity == null)
        {
            return false;
        }

        return RecycleBinId == Constants.System.RecycleBinContent
            ? _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.HasContentPathAccess(entity, _entityService, _appCaches) ?? false
            : _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.HasMediaPathAccess(entity, _entityService, _appCaches) ?? false;
    }

    /// <summary>
    ///     Ensures the recycle bin is appended when required (i.e. user has access to the root and it's not in dialog mode)
    /// </summary>
    /// <param name="id"></param>
    /// <param name="queryStrings"></param>
    /// <returns></returns>
    /// <remarks>
    ///     This method is overwritten strictly to render the recycle bin, it should serve no other purpose
    /// </remarks>
    protected sealed override ActionResult<TreeNodeCollection> GetTreeNodes(string id, FormCollection queryStrings)
    {
        //check if we're rendering the root
        if (id == Constants.System.RootString && UserStartNodes.Contains(Constants.System.Root))
        {
            var altStartId = string.Empty;

            if (queryStrings.HasKey(TreeQueryStringParameters.StartNodeId))
            {
                altStartId = queryStrings.GetValue<string>(TreeQueryStringParameters.StartNodeId);
            }

            //check if a request has been made to render from a specific start node
            if (string.IsNullOrEmpty(altStartId) == false && altStartId != "undefined" &&
                altStartId != Constants.System.RootString)
            {
                id = altStartId;
            }

            ActionResult<TreeNodeCollection> nodesResult = GetTreeNodesInternal(id, queryStrings);
            if (!(nodesResult.Result is null))
            {
                return nodesResult.Result;
            }

            TreeNodeCollection? nodes = nodesResult.Value;

            //only render the recycle bin if we are not in dialog and the start id is still the root
            //we need to check for the "application" key in the queryString because its value is required here,
            //and for some reason when there are no dashboards, this parameter is missing
            if (IsDialog(queryStrings) == false && id == Constants.System.RootString &&
                queryStrings.HasKey("application"))
            {
                nodes?.Add(CreateTreeNode(
                    RecycleBinId.ToInvariantString(),
                    id,
                    queryStrings,
                    LocalizedTextService.Localize("general", "recycleBin"),
                    "icon-trash",
                    RecycleBinSmells,
                    queryStrings.GetRequiredValue<string>("application") + TreeAlias.EnsureStartsWith('/') +
                    "/recyclebin"));
            }

            return nodes ?? new TreeNodeCollection();
        }

        return GetTreeNodesInternal(id, queryStrings);
    }

    /// <summary>
    ///     Check to see if we should return children of a container node
    /// </summary>
    /// <param name="e"></param>
    /// <returns></returns>
    /// <remarks>
    ///     This is required in case a user has custom start nodes that are children of a list view since in that case we'll
    ///     need to render the tree node. In normal cases we don't render
    ///     children of a list view.
    /// </remarks>
    protected bool ShouldRenderChildrenOfContainer(IEntitySlim e)
    {
        var isContainer = e.IsContainer;

        var renderChildren = e.HasChildren && isContainer == false;

        //Here we need to figure out if the node is a container and if so check if the user has a custom start node, then check if that start node is a child
        // of this container node. If that is true, the HasChildren must be true so that the tree node still renders even though this current node is a container/list view.
        if (isContainer && UserStartNodes.Length > 0 && UserStartNodes.Contains(Constants.System.Root) == false)
        {
            IEnumerable<IEntitySlim> startNodes = _entityService.GetAll(UmbracoObjectType, UserStartNodes);
            //if any of these start nodes' parent is current, then we need to render children normally so we need to switch some logic and tell
            // the UI that this node does have children and that it isn't a container

            if (startNodes.Any(x =>
                {
                    var pathParts = x.Path.Split(Constants.CharArrays.Comma);
                    return pathParts.Contains(e.Id.ToInvariantString());
                }))
            {
                renderChildren = true;
            }
        }

        return renderChildren;
    }

    /// <summary>
    ///     Before we make a call to get the tree nodes we have to check if they can actually be rendered
    /// </summary>
    /// <param name="id"></param>
    /// <param name="queryStrings"></param>
    /// <returns></returns>
    /// <remarks>
    ///     Currently this just checks if it is a container type, if it is we cannot render children. In the future this might
    ///     check for other things.
    /// </remarks>
    private ActionResult<TreeNodeCollection> GetTreeNodesInternal(string id, FormCollection queryStrings)
    {
        IEntitySlim? current = GetEntityFromId(id);

        //before we get the children we need to see if this is a container node

        //test if the parent is a listview / container
        if (current != null && ShouldRenderChildrenOfContainer(current) == false)
        {
            //no children!
            return new TreeNodeCollection();
        }

        return PerformGetTreeNodes(id, queryStrings);
    }

    /// <summary>
    ///     Checks if the menu requested is for the recycle bin and renders that, otherwise renders the result of
    ///     PerformGetMenuForNode
    /// </summary>
    /// <param name="id"></param>
    /// <param name="queryStrings"></param>
    /// <returns></returns>
    protected sealed override ActionResult<MenuItemCollection> GetMenuForNode(string id, FormCollection queryStrings)
    {
        if (RecycleBinId.ToInvariantString() == id)
        {
            // get the default assigned permissions for this user
            var deleteAllowed = false;
            IAction? deleteAction = _actionCollection.FirstOrDefault(y => y.Letter == ActionDelete.ActionLetter);
            if (deleteAction != null)
            {
                IEnumerable<string>? perms =
                    _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.GetPermissions(
                        Constants.System.RecycleBinContentString, _userService);
                deleteAllowed = perms?.FirstOrDefault(x => x.Contains(deleteAction.Letter)) != null;
            }

            MenuItemCollection menu = MenuItemCollectionFactory.Create();

            // only add empty recycle bin if the current user is allowed to delete by default
            if (deleteAllowed)
            {
                menu.Items.Add(new MenuItem("emptyrecyclebin", LocalizedTextService)
                {
                    Icon = "icon-trash",
                    OpensDialog = true,
                    UseLegacyIcon = false,
                });

                menu.Items.Add(new RefreshNode(LocalizedTextService, true));
            }

            return menu;
        }

        return PerformGetMenuForNode(id, queryStrings);
    }

    /// <summary>
    ///     Based on the allowed actions, this will filter the ones that the current user is allowed
    /// </summary>
    /// <param name="menuWithAllItems"></param>
    /// <param name="userAllowedMenuItems"></param>
    /// <returns></returns>
    protected void FilterUserAllowedMenuItems(MenuItemCollection menuWithAllItems, IEnumerable<MenuItem> userAllowedMenuItems)
    {
        IAction?[] userAllowedActions =
            userAllowedMenuItems.Where(x => x.Action != null).Select(x => x.Action).ToArray();

        MenuItem[] notAllowed = menuWithAllItems.Items.Where(
                a => a.Action != null
                     && a.Action.CanBePermissionAssigned
                     && (a.Action.CanBePermissionAssigned == false || userAllowedActions.Contains(a.Action) == false))
            .ToArray();

        //remove the ones that aren't allowed.
        foreach (MenuItem m in notAllowed)
        {
            menuWithAllItems.Items.Remove(m);
            // if the disallowed action is set as default action, make sure to reset the default action as well
            if (menuWithAllItems.DefaultMenuAlias == m.Alias)
            {
                menuWithAllItems.DefaultMenuAlias = null;
            }
        }
    }

    internal IEnumerable<MenuItem> GetAllowedUserMenuItemsForNode(IUmbracoEntity dd)
    {
        IEnumerable<string> permissionsForPath = _userService
            .GetPermissionsForPath(_backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser, dd.Path)
            .GetAllPermissions();
        return _actionCollection.GetByLetters(permissionsForPath).Select(x => new MenuItem(x));
    }

    /// <summary>
    ///     Determines if the user has access to view the node/document
    /// </summary>
    /// <param name="doc">The Document to check permissions against</param>
    /// <param name="allowedUserOptions">A list of MenuItems that the user has permissions to execute on the current document</param>
    /// <param name="culture">The culture of the node</param>
    /// <remarks>By default the user must have Browse permissions to see the node in the Content tree</remarks>
    /// <returns></returns>
    internal bool CanUserAccessNode(IUmbracoEntity doc, IEnumerable<MenuItem> allowedUserOptions, string? culture) =>
        // TODO: At some stage when we implement permissions on languages we'll need to take care of culture
        allowedUserOptions.Select(x => x.Action).OfType<ActionBrowse>().Any();


    /// <summary>
    ///     this will parse the string into either a GUID or INT
    /// </summary>
    /// <param name="id"></param>
    /// <returns></returns>
    internal Tuple<Guid?, int?>? GetIdentifierFromString(string id)
    {

        if (Guid.TryParse(id, out Guid idGuid))
        {
            return new Tuple<Guid?, int?>(idGuid, null);
        }

        if (int.TryParse(id, NumberStyles.Integer, CultureInfo.InvariantCulture, out int idInt))
        {
            return new Tuple<Guid?, int?>(null, idInt);
        }

        if (UdiParser.TryParse(id, out Udi? idUdi))
        {
            var guidUdi = idUdi as GuidUdi;
            if (guidUdi != null)
            {
                return new Tuple<Guid?, int?>(guidUdi.Guid, null);
            }
        }

        return null;
    }

    /// <summary>
    ///     Get an entity via an id that can be either an integer, Guid or UDI
    /// </summary>
    /// <param name="id"></param>
    /// <returns></returns>
    /// <remarks>
    ///     This object has it's own contextual cache for these lookups
    /// </remarks>
    internal IEntitySlim? GetEntityFromId(string id) =>
        _entityCache.GetOrAdd(id, s =>
        {
            IEntitySlim? entity;

            if (Guid.TryParse(s, out Guid idGuid))
            {
                entity = _entityService.Get(idGuid, UmbracoObjectType);
            }
            else if (int.TryParse(s, NumberStyles.Integer, CultureInfo.InvariantCulture, out var idInt))
            {
                entity = _entityService.Get(idInt, UmbracoObjectType);
            }
            else if (UdiParser.TryParse(s, out Udi? idUdi))
            {
                var guidUdi = idUdi as GuidUdi;
                entity = guidUdi != null ? _entityService.Get(guidUdi.Guid, UmbracoObjectType) : null;
            }
            else
            {
                entity = null;
            }

            return entity;
        });


    /// <summary>
    ///     If the request should allows a user to choose nodes that they normally don't have access to
    /// </summary>
    /// <param name="queryStrings"></param>
    /// <returns></returns>
    internal bool IgnoreUserStartNodes(FormCollection queryStrings)
    {
        if (_ignoreUserStartNodes.HasValue)
        {
            return _ignoreUserStartNodes.Value;
        }

        Guid? dataTypeKey = queryStrings.GetValue<Guid?>(TreeQueryStringParameters.DataTypeKey);
        _ignoreUserStartNodes =
            dataTypeKey.HasValue && _dataTypeService.IsDataTypeIgnoringUserStartNodes(dataTypeKey.Value);

        return _ignoreUserStartNodes.Value;
    }
}