@openui5/sap.ui.core/src/sap/ui/model/odata/v2/ODataTreeBinding.js

OpenUI5 Core Library sap.ui.core

/*!
 * OpenUI5
 * (c) Copyright 2009-2021 SAP SE or an SAP affiliate company.
 * Licensed under the Apache License, Version 2.0 - see LICENSE.txt.
 */

// Provides the OData model implementation of a tree binding
sap.ui.define([
	"sap/base/assert",
	"sap/base/Log",
	"sap/base/util/includes",
	"sap/base/util/isEmptyObject",
	'sap/ui/model/ChangeReason',
	'sap/ui/model/Context',
	'sap/ui/model/Filter',
	'sap/ui/model/FilterProcessor',
	'sap/ui/model/FilterType',
	'sap/ui/model/Sorter',
	'sap/ui/model/SorterProcessor',
	'sap/ui/model/TreeBinding',
	'sap/ui/model/TreeBindingUtils',
	'sap/ui/model/odata/CountMode',
	'sap/ui/model/odata/ODataUtils',
	'sap/ui/model/odata/OperationMode',
	"sap/ui/thirdparty/jquery"
], function(assert, Log, includes, isEmptyObject, ChangeReason, Context, Filter, FilterProcessor,
		FilterType, Sorter, SorterProcessor, TreeBinding, TreeBindingUtils, CountMode, ODataUtils,
		OperationMode, jQuery) {
	"use strict";

	/**
	 * Do <strong>NOT</strong> call this private constructor, but rather use
	 * {@link sap.ui.model.odata.v2.ODataModel#bindTree} instead!
	 *
	 * @param {sap.ui.model.odata.v2.ODataModel} oModel
	 *   The OData V2 model
	 * @param {string} sPath
	 *   The binding path, either absolute or relative to a given <code>oContext</code>
	 * @param {sap.ui.model.Context} [oContext]
	 *   The parent context which is required as base for a relative path
	 * @param {sap.ui.model.Filter | sap.ui.model.Filter[]} [vFilters]
	 *   The application filters to be used initially
	 * @param {object} [mParameters]
	 *   Map of binding parameters
	 * @param {object} [mParameters.treeAnnotationProperties]
	 *   The mapping between data properties and the hierarchy used to visualize the tree, if not
	 *   provided by the service's metadata
	 * @param {string} [mParameters.treeAnnotationProperties.hierarchyLevelFor]
	 *   The property name in the same type holding the hierarchy level information
	 * @param {string} [mParameters.treeAnnotationProperties.hierarchyNodeFor]
	 *   The property name in the same type holding the hierarchy node id
	 * @param {string} [mParameters.treeAnnotationProperties.hierarchyParentNodeFor]
	 *   The property name in the same type holding the parent node id
	 * @param {string} [mParameters.treeAnnotationProperties.hierarchyDrillStateFor]
	 *   The property name in the same type holding the drill state for the node
	 * @param {string} [mParameters.treeAnnotationProperties.hierarchyNodeDescendantCountFor]
	 *   The property name in the same type holding the descendant count for the node
	 * @param {number} [mParameters.numberOfExpandedLevels=0]
	 *   The number of levels that are auto-expanded initially
	 * @param {number} [mParameters.rootLevel=0]
	 *   The level of the topmost tree nodes
	 * @param {string} [mParameters.groupId]
	 *   The group id to be used for requests originating from this binding
	 * @param {sap.ui.model.odata.OperationMode} [mParameters.operationMode]
	 *   The operation mode for this binding
	 * @param {number} [mParameters.threshold]
	 *   The threshold used if the operation mode is set to
	 *   {@link sap.ui.model.odata.OperationMode.Auto OperationMode.Auto}
	 * @param {boolean} [mParameters.useServersideApplicationFilters]
	 *   Whether <code>$filter</code> statements should be used for the <code>$count</code> /
	 *   <code>$inlinecount</code> requests and for the data request if the operation mode is
	 *   {@link sap.ui.model.odata.OperationMode.Auto OperationMode.Auto}
	 * @param {any} [mParameters.treeState]
	 *   A tree state handle
	 *  @param {sap.ui.model.odata.CountMode} [mParameters.countMode]
	 *    The count mode of this binding
	 *  @param {boolean} [mParameters.usePreliminaryContext]
	 *    Whether a preliminary context is used
	 * @param {string} [mParameters.batchGroupId]
	 *   <b>Deprecated</b>, use <code>groupId</code> instead
	 * @param {object} [mParameters.navigation]
	 *   <b>Deprecated since 1.44:</b> A map describing the navigation properties between entity
	 *   sets, which is used for constructing and paging the tree
	 * @param {sap.ui.model.Sorter | sap.ui.model.Sorter[]} [vSorters]
	 *   The dynamic sorters to be used initially
	 *
	 * @alias sap.ui.model.odata.v2.ODataTreeBinding
	 * @author SAP SE
	 * @class Tree binding implementation for the {@link sap.ui.model.odata.v2.ODataModel}. Use
	 *   {@link sap.ui.model.odata.v2.ODataModel#bindTree} for creating an instance.
	 * @extends sap.ui.model.TreeBinding
	 * @hideconstructor
	 * @public
	 * @version 1.87.1
	 */
	var ODataTreeBinding = TreeBinding.extend("sap.ui.model.odata.v2.ODataTreeBinding", /** @lends sap.ui.model.odata.v2.ODataTreeBinding.prototype */ {

		constructor : function (oModel, sPath, oContext, vFilters, mParameters, vSorters) {
			TreeBinding.apply(this, arguments);

			//make sure we have at least an empty parameter object
			this.mParameters = this.mParameters || mParameters || {};

			this.sGroupId;
			this.sRefreshGroupId;
			this.oFinalLengths = {};
			this.oLengths = {};
			this.oKeys = {};
			this.bNeedsUpdate = false;
			this._bRootMissing = false;
			this.bSkipDataEvents = false;

			if (vSorters instanceof Sorter) {
				vSorters = [vSorters];
			}
			this.aSorters = vSorters || [];
			this.sFilterParams = "";

			this.mNormalizeCache = {};

			// The ODataTreeBinding expects there to be only an array in this.aApplicationFilters later on.
			// Wrap the given application filters inside an array if necessary
			if (vFilters instanceof Filter) {
				vFilters = [vFilters];
			}
			this.aApplicationFilters = vFilters;

			// check filter integrity
			this.oModel.checkFilterOperation(this.aApplicationFilters);

			// a queue containing all parallel running requests
			// a request is identified by (node id, startindex, length)
			this.mRequestHandles = {};

			this.oRootContext = null;

			this.iNumberOfExpandedLevels = (mParameters && mParameters.numberOfExpandedLevels) || 0;
			this.iRootLevel =  (mParameters && mParameters.rootLevel) || 0;

			this.sCountMode = (mParameters && mParameters.countMode) || this.oModel.sDefaultCountMode;
			if (this.sCountMode == CountMode.None) {
				Log.fatal("To use an ODataTreeBinding at least one CountMode must be supported by the service!");
			}

			if (mParameters) {
				this.sGroupId = mParameters.groupId || mParameters.batchGroupId;
			}

			this.bInitial = true;
			this._mLoadedSections = {};
			this._iPageSize = 0;

			// external operation mode
			this.sOperationMode = (mParameters && mParameters.operationMode) || this.oModel.sDefaultOperationMode;
			if (this.sOperationMode === OperationMode.Default) {
				this.sOperationMode = OperationMode.Server;
			}

			// internal operation mode switch, default is the same as "OperationMode.Server"
			this.bClientOperation = false;

			// the internal operation mode might change, the external operation mode (this.sOperationMode) will always be the original value
			switch (this.sOperationMode) {
				case OperationMode.Server: this.bClientOperation = false; break;
				case OperationMode.Client: this.bClientOperation = true; break;
				case OperationMode.Auto: this.bClientOperation = false; break; //initially start the same as the server mode
			}

			// the threshold for the OperationMode.Auto
			this.iThreshold = (mParameters && mParameters.threshold) || 0;

			// flag to check if the threshold was rejected after a count was issued
			this.bThresholdRejected = false;

			// the total collection count is the number of entries available in the backend (starting at the given rootLevel)
			this.iTotalCollectionCount = null;

			// a flag to decide if the OperationMode.Auto should "useServersideApplicationFilters", by default the filters are omitted.
			this.bUseServersideApplicationFilters = (mParameters && mParameters.useServersideApplicationFilters) || false;
			this.bUsePreliminaryContext = this.mParameters.usePreliminaryContext
				|| oModel.bPreliminaryContext;

			this.oAllKeys = null;
			this.oAllLengths = null;
			this.oAllFinalLengths = null;
		}

	});

	/**
	 * Drill-States for Hierarchy-Nodes
	 *
	 * From the spec:
	 * A property holding the drill state of a hierarchy node includes this attribute.
	 * The drill state is indicated by one of the following values: collapsed, expanded, leaf.
	 * The value of this attribute is always the name of another property in the same type.
	 * It points to the related property holding the hierarchy node ID.
	 */
	ODataTreeBinding.DRILLSTATES = {
		Collapsed: "collapsed",
		Expanded: "expanded",
		Leaf: "leaf"
	};

	/**
	 * Builds a node filter string.
	 * mParams.id holds the ID value for filtering on the hierarchy node.
	 */
	ODataTreeBinding.prototype._getNodeFilterParams = function (mParams) {
		var sPropName = mParams.isRoot ? this.oTreeProperties["hierarchy-node-for"] : this.oTreeProperties["hierarchy-parent-node-for"];
		var oEntityType = this._getEntityType();
		return ODataUtils._createFilterParams(new Filter(sPropName, "EQ", mParams.id), this.oModel.oMetadata, oEntityType);
	};

	/**
	 * Builds the Level-Filter string
	 */
	ODataTreeBinding.prototype._getLevelFilterParams = function (sOperator, iLevel) {
		var oEntityType = this._getEntityType();
		return ODataUtils._createFilterParams(new Filter(this.oTreeProperties["hierarchy-level-for"], sOperator, iLevel), this.oModel.oMetadata, oEntityType);
	};

	/**
	 * Retrieves the root node given through sNodeId
	 * @param {string} sNodeId the ID od the root node which should be loaded (e.g. when bound to a single entity)
	 * @param {string} sRequestKey a key string used to store/clean-up request handles
	 * @private
	 */
	ODataTreeBinding.prototype._loadSingleRootNodeByNavigationProperties = function (sNodeId, sRequestKey) {
		var that = this,
			sGroupId;

		if (this.mRequestHandles[sRequestKey]) {
			this.mRequestHandles[sRequestKey].abort();
		}
		sGroupId = this.sRefreshGroupId ? this.sRefreshGroupId : this.sGroupId;
		var sAbsolutePath = this.oModel.resolve(this.getPath(), this.getContext());
		if (sAbsolutePath) {
			this.mRequestHandles[sRequestKey] = this.oModel.read(sAbsolutePath, {
				groupId: sGroupId,
				success: function (oData) {
					var sNavPath = that._getNavPath(that.getPath());

					if (oData) {
						// we expect only one root node
						var oEntry = oData;
						var sKey =  that.oModel._getKey(oEntry);
						var oNewContext = that.oModel.getContext('/' + sKey);

						that.oRootContext = oNewContext;
						that._processODataObject(oNewContext.getObject(), sNodeId, sNavPath);
					} else {
						that._bRootMissing = true;
					}
					that.bNeedsUpdate = true;

					delete that.mRequestHandles[sRequestKey];

					that.oModel.callAfterUpdate(function() {
						that.fireDataReceived({data: oData});
					});
				},
				error: function (oError) {
					//Only perform error handling if the request was not aborted intentionally
					if (oError && oError.statusCode != 0 && oError.statusText != "abort") {
						that.bNeedsUpdate = true;
						that._bRootMissing = true;
						delete that.mRequestHandles[sRequestKey];
						that.fireDataReceived();
					}
				}
			});
		}
	};

	/**
	 * Returns root contexts for the tree. You can specify the start index and the length for paging requests.
	 * This function is not available when the annotation "hierarchy-node-descendant-count-for" is exposed on the service.
	 *
	 * @param {int} [iStartIndex=0] the start index of the requested contexts
	 * @param {int} [iLength=v2.ODataModel.sizeLimit] the requested amount of contexts. If none given, the default value is the size limit of the underlying
	 *												 sap.ui.model.odata.v2.ODataModel instance.
	 * @param {int} [iThreshold=0] the number of entities which should be retrieved in addition to the given length.
	 *				  A higher threshold reduces the number of backend requests, yet these request blow up in size, since more data is loaded.
	 * @return {sap.ui.model.Context[]} an array containing the contexts for the entities returned by the backend, might be fewer than requested
	 *								  if the backend does not have enough data.
	 * @public
	 */
	ODataTreeBinding.prototype.getRootContexts = function(iStartIndex, iLength, iThreshold) {

		var sNodeId = null,
			mRequestParameters = {
				numberOfExpandedLevels: this.iNumberOfExpandedLevels
			},
			aRootContexts = [];

		if (this.isInitial()) {
			return aRootContexts;
		}

		// make sure the input parameters are not undefined
		iStartIndex = iStartIndex || 0;
		iLength = iLength || this.oModel.sizeLimit;
		iThreshold = iThreshold || 0;

		// node ID for the root context(s) ~> null
		// startindex/length may differ due to paging
		// same node id + different paging sections are treated as different requests and will not abort each other
		var sRequestKey = "" + sNodeId + "-" + iStartIndex + "-" + this._iPageSize + "-" + iThreshold;

		if (this.bHasTreeAnnotations) {

			this.bDisplayRootNode = true;
			// load root level, node id is "null" in this case
			aRootContexts = this._getContextsForNodeId(null, iStartIndex, iLength, iThreshold);

		} else {
			sNodeId = this.oModel.resolve(this.getPath(), this.getContext());

			var bIsList = this.oModel.isList(this.sPath, this.getContext());
			if (bIsList) {
				this.bDisplayRootNode = true;
			}

			if (this.bDisplayRootNode && !bIsList) {
				if (this.oRootContext) {
					return [this.oRootContext];
				} else if (this._bRootMissing) {
					// the backend may not return anything for the given root node, so in this case our root node is missing
					return [];
				} else {
					this._loadSingleRootNodeByNavigationProperties(sNodeId, sRequestKey);
				}
			} else {
				mRequestParameters.navPath = this._getNavPath(this.getPath());

				//append nav path if binding path is not a collection and the root node should not be displayed
				if (!this.bDisplayRootNode) {
					sNodeId += "/" + mRequestParameters.navPath;
				}
				aRootContexts = this._getContextsForNodeId(sNodeId, iStartIndex, iLength, iThreshold, mRequestParameters);
			}

		}

		return aRootContexts;
	};

	/**
	 * Returns the contexts of the child nodes for the given context. This function is not available when the annotation "hierarchy-node-descendant-count-for"
	 * is exposed on the service.
	 *
	 * @param {sap.ui.model.Context} oContext the context for which the child nodes should be retrieved
	 * @param {int} iStartIndex the start index of the requested contexts
	 * @param {int} iLength the requested amount of contexts
	 * @param {int} iThreshold
	 * @return {sap.ui.model.Context[]} the contexts array
	 * @public
	 */
	ODataTreeBinding.prototype.getNodeContexts = function(oContext, iStartIndex, iLength, iThreshold) {

		var sNodeId,
			mRequestParameters = {};

		if (this.isInitial()) {
			return [];
		}

		if (this.bHasTreeAnnotations) {
			// previously only the Hierarchy-ID-property from the data was used as key but not the actual OData-Key
			// now the actual key of the odata entry is used
			sNodeId = this.oModel.getKey(oContext);
			mRequestParameters.level = parseInt(oContext.getProperty(this.oTreeProperties["hierarchy-level-for"])) + 1;
		} else {
			var sNavPath = this._getNavPath(oContext.getPath());

			//If no nav path was found no nav property is defined and we cannot find any more data
			if (!sNavPath) {
				return [];
			}

			sNodeId = this.oModel.resolve(sNavPath, oContext);
			mRequestParameters.navPath = this.oNavigationPaths[sNavPath];
		}

		return this._getContextsForNodeId(sNodeId, iStartIndex, iLength, iThreshold, mRequestParameters);
	};

	/**
	 * Returns if the node has child nodes.
	 * If the ODataTreeBinding is running with hierarchy annotations, a context with the property values "expanded" or "collapsed"
	 * for the drilldown state property, returns true. Entities with drilldown state "leaf" return false.
	 *
	 * This function is not available when the annotation "hierarchy-node-descendant-count-for" is exposed on the service.
	 *
	 * @param {sap.ui.model.Context} oContext the context element of the node
	 * @return {boolean} true if node has children
	 *
	 * @public
	 */
	ODataTreeBinding.prototype.hasChildren = function(oContext) {
		if (this.bHasTreeAnnotations) {
			if (!oContext) {
				return false;
			}
			var sDrilldownState = oContext.getProperty(this.oTreeProperties["hierarchy-drill-state-for"]);

			var sNodeKey = this.oModel.getKey(oContext);
			//var sHierarchyNode = oContext.getProperty(this.oTreeProperties["hierarchy-node-for"]);

			var iLength = this.oLengths[sNodeKey];

			// if the server returned no children for a node (even though it has a DrilldownState of "expanded"),
			// the length for this node is set to 0 and finalized -> no children available
			if (iLength === 0 && this.oFinalLengths[sNodeKey]) {
				return false;
			}
			// leaves do not have childre, only "expanded" and "collapsed" nodes
			// Beware: the drilldownstate may be undefined/empty string,
			//		 in case the entity (oContext) has no value for the drilldown state property
			if (sDrilldownState === "expanded" || sDrilldownState === "collapsed") {
				return true;
			} else if (sDrilldownState === "leaf"){
				return false;
			} else {
				Log.warning("The entity '" + oContext.getPath() + "' has not specified Drilldown State property value.");
				//fault tolerance for empty property values (we optimistically say that those nodes can be expanded/collapsed)
				if (sDrilldownState === undefined || sDrilldownState === "") {
					return true;
				}
				return false;
			}
		} else {
			if (!oContext) {
				return this.oLengths[this.getPath()] > 0;
			}
			var iLength = this.oLengths[oContext.getPath() + "/" + this._getNavPath(oContext.getPath())];

			//only return false if we definitely know that the length is 0, otherwise, we have either a known length or none at all (undefined)
			return iLength !== 0;
		}
	};

	/**
	 * Returns the number of child nodes. This function is not available when the annotation "hierarchy-node-descendant-count-for"
	 * is exposed on the service.
	 *
	 * @param {Object} oContext the context element of the node
	 * @return {int} the number of children
	 *
	 * @public
	 */
	ODataTreeBinding.prototype.getChildCount = function(oContext) {
		if (this.bHasTreeAnnotations) {
			var vHierarchyNode;
			// only the root node should have no context
			// the child count is either stored via the rootNodeId or (if only the rootLevel is given) as "null", because we do not know the root id
			if (!oContext) {
				vHierarchyNode = null;
			} else {
				vHierarchyNode = this.oModel.getKey(oContext);
			}
			return this.oLengths[vHierarchyNode];
		} else {
			if (!oContext) {
				// if no context was given, we retrieve the top-level child count:
				// 1. in case the binding path is a collection we need use the binding path as a key in the length map
				// 2. in case the binding path is a single entity, we need to add the navigation property from the "$expand" query option
				if (!this.bDisplayRootNode) {
					return this.oLengths[this.getPath() + "/" + this._getNavPath(this.getPath())];
				} else {
					return this.oLengths[this.getPath()];
				}
			}
			return this.oLengths[oContext.getPath() + "/" + this._getNavPath(oContext.getPath())];
		}
	};

	/**
	 * Gets or loads all contexts for a specified node id (dependent on mode)
	 *
	 * @param {string} sNodeId the value of the hierarchy node property on which a parent node filter will be performed
	 * @param {int} iStartIndex start index of the page
	 * @param {int} iLength length of the page
	 * @param {int} iThreshold additionally loaded entities
	 * @param {object} mParameters additional request parameters
	 *
	 * @return {sap.ui.model.Context[]} Array of contexts
	 *
	 * @private
	 */
	ODataTreeBinding.prototype._getContextsForNodeId = function(sNodeId, iStartIndex, iLength, iThreshold, mRequestParameters) {
		var aContexts = [],
			sKey;

		// OperationMode.Auto: handle synchronized count to check what the actual internal operation mode should be
		// If the $count or $inlinecount is used, is determined by the respective
		if (this.sOperationMode == OperationMode.Auto) {
			// as long as we do not have a collection count, we return an empty array
			if (this.iTotalCollectionCount == null) {
				if (!this.bCollectionCountRequested) {
					this._getCountForCollection();
					this.bCollectionCountRequested = true;
				}
				return [];
			}
		}

		// Set default values if startindex, threshold or length are not defined
		iStartIndex = iStartIndex || 0;
		iLength = iLength || this.oModel.iSizeLimit;
		iThreshold = iThreshold || 0;

		// re-set the threshold in OperationMode.Auto
		// between binding-treshold and the threshold given as an argument, the bigger one will be taken
		if (this.sOperationMode == OperationMode.Auto) {
			if (this.iThreshold >= 0) {
				iThreshold = Math.max(this.iThreshold, iThreshold);
			}
		}

		if (!this._mLoadedSections[sNodeId]) {
			this._mLoadedSections[sNodeId] = [];
		}

		// make sure we only request the maximum length available (length is known and final)
		if (this.oFinalLengths[sNodeId] && this.oLengths[sNodeId] < iStartIndex + iLength) {
			iLength = Math.max(this.oLengths[sNodeId] - iStartIndex, 0);
		}

		var that = this;
		// check whether a start index was already requested
		var fnFindInLoadedSections = function(iStartIndex) {
			// check in the sections which where loaded
			for (var i = 0; i < that._mLoadedSections[sNodeId].length; i++) {
				var oSection = that._mLoadedSections[sNodeId][i];
				// try to find i in the loaded sections. If i is within one of the sections it needs not to be loaded again
				if (iStartIndex >= oSection.startIndex && iStartIndex < oSection.startIndex + oSection.length) {
					return true;
				}
			}

			// check requested sections where we still wait for an answer
		};

		var aMissingSections = [];
		// Loop through known data and check whether we already have all rows loaded
		// make sure to also check that the entities before the requested start index can be served
		var i = Math.max((iStartIndex - iThreshold - this._iPageSize), 0);
		if (this.oKeys[sNodeId]) {

			// restrict loop to the maximum available length if we have a $(inline)count
			// this will make sure we do not find "missing" sections at the end of the known datablock, if it is outside the $(inline)count
			var iMaxIndexToCheck = iStartIndex + iLength + (iThreshold);
			if (this.oLengths[sNodeId]) {
				iMaxIndexToCheck = Math.min(iMaxIndexToCheck, this.oLengths[sNodeId]);
			}

			for (i; i < iMaxIndexToCheck; i++) {
				sKey = this.oKeys[sNodeId][i];
				if (!sKey) {
					//only collect missing sections if we are running in the internal operationMode "Server" -> bClientOperation = false
					if (!this.bClientOperation && !fnFindInLoadedSections(i)) {
						aMissingSections = TreeBindingUtils.mergeSections(aMissingSections, {startIndex: i, length: 1});
					}
				}

				// collect requested contexts if loaded
				if (i >= iStartIndex && i < iStartIndex + iLength) {
					if (sKey) {
						aContexts.push(this.oModel.getContext('/' + sKey));
					} else {
						aContexts.push(undefined);
					}
				}
			}

			// check whether the missing section already spans the complete page. If this is the case, we don't need to request an additional page
			var iBegin = Math.max((iStartIndex - iThreshold - this._iPageSize), 0);
			var iEnd = iStartIndex + iLength + (iThreshold);
			var bExpandThreshold = aMissingSections[0] && aMissingSections[0].startIndex === iBegin && aMissingSections[0].startIndex + aMissingSections[0].length === iEnd;

			if (aMissingSections.length > 0 && !bExpandThreshold) {
				//first missing section will be prepended with additional threshold ("negative")
				i = Math.max((aMissingSections[0].startIndex - iThreshold - this._iPageSize), 0);
				var iFirstStartIndex = aMissingSections[0].startIndex;
				for (i; i < iFirstStartIndex; i++) {
					var sKey = this.oKeys[sNodeId][i];
					if (!sKey) {
						if (!fnFindInLoadedSections(i)) {
							aMissingSections = TreeBindingUtils.mergeSections(aMissingSections, {startIndex: i, length: 1});
						}
					}
				}

				//last missing section will be appended with additional threshold ("positive")
				i = aMissingSections[aMissingSections.length - 1].startIndex + aMissingSections[aMissingSections.length - 1].length;
				var iEndIndex = i + iThreshold + this._iPageSize;
				// if we already have a count -> clamp the end index
				if (this.oLengths[sNodeId]) {
					iEndIndex = Math.min(iEndIndex, this.oLengths[sNodeId]);
				}

				for (i; i < iEndIndex; i++) {
					var sKey = this.oKeys[sNodeId][i];
					if (!sKey) {
						if (!fnFindInLoadedSections(i)) {
							aMissingSections = TreeBindingUtils.mergeSections(aMissingSections, {startIndex: i, length: 1});
						}
					}
				}
			}
		} else {
			// for initial loading of a node use this shortcut.
			if (!fnFindInLoadedSections(iStartIndex)) {
				// "i" is our shifted forward startIndex for the "negative" thresholding
				// in this case i is always smaller than iStartIndex, but minimum is 0
				var iLengthShift = iStartIndex - i;
				aMissingSections = TreeBindingUtils.mergeSections(aMissingSections, {startIndex: i, length: iLength + iLengthShift + iThreshold});
			}
		}

		// check if metadata are already available
		if (this.oModel.getServiceMetadata()) {
			// If rows are missing send a request
			if (aMissingSections.length > 0) {
				var aParams = [];
				var sFilterParams = "";
				if (this.bHasTreeAnnotations) {

					if (this.sOperationMode == "Server" || this.bUseServersideApplicationFilters) {
						sFilterParams = this.getFilterParams();
						//sFilterParams = sFilterParams ? "%20and%20" + sFilterParams : "";
					}

					if (sNodeId) {
						sFilterParams = sFilterParams ? "%20and%20" + sFilterParams : "";

						//retrieve the correct context for the sNodeId (it's an OData-Key) and resolve the correct hierarchy node property as a filter value
						var oNodeContext = this.oModel.getContext("/" + sNodeId);
						var sNodeIdForFilter = oNodeContext.getProperty(this.oTreeProperties["hierarchy-node-for"]);

						//construct node filter parameter
						var sNodeFilterParameter = this._getNodeFilterParams({id: sNodeIdForFilter});
						aParams.push("$filter=" + sNodeFilterParameter + sFilterParams);
					} else if (sNodeId == null) {
						// no root node id is given: sNodeId === null
						// in this case we use the root level

						// in case the binding runs in OperationMode Server -> the level filter is EQ by default,
						// for the Client OperationMode GT is used to fetch all nodes below the given level
						// The only exception here is the rootLevel 0:
						// if the root Level is 0, we do not send any level filters, since by specification the top level nodes are on level 0
						// this is for compatibility reasons with different backend-systems, which do not support GE operators on the level
						var sLevelFilter = "";
						if (!this.bClientOperation || this.iRootLevel > 0) {
							var sLevelFilterOperator = this.bClientOperation ? "GE" : "EQ";
							sLevelFilter = this._getLevelFilterParams(sLevelFilterOperator, this.iRootLevel);
						}

						//only build filter statement if necessary
						if (sLevelFilter || sFilterParams) {
							//if we have a level filter AND an application filter, we need to add an escaped "AND" to between
							if (sFilterParams && sLevelFilter) {
								sFilterParams = "%20and%20" + sFilterParams;
							}
							aParams.push("$filter=" + sLevelFilter + sFilterParams);
						}
					}
				} else {
					// append application filters for navigation property case
					sFilterParams = this.getFilterParams();
					if (sFilterParams) {
						aParams.push("$filter=" + sFilterParams);
					}
				}

				if (this.sCustomParams) {
					aParams.push(this.sCustomParams);
				}

				if (!this.bClientOperation) {
					// request the missing sections and manage the loaded sections map
					for (i = 0; i < aMissingSections.length; i++) {
						var oRequestedSection = aMissingSections[i];
						this._mLoadedSections[sNodeId] = TreeBindingUtils.mergeSections(this._mLoadedSections[sNodeId], {startIndex: oRequestedSection.startIndex, length: oRequestedSection.length});
						this._loadSubNodes(sNodeId, oRequestedSection.startIndex, oRequestedSection.length, 0, aParams, mRequestParameters, oRequestedSection);
					}
				} else {
					// OperationMode is set to "Client" AND we have something missing (should only happen once, at the very first loading request)
					// of course also make sure no request is running already
					if (!this.oAllKeys && !this.mRequestHandles[ODataTreeBinding.REQUEST_KEY_CLIENT]) {
						this._loadCompleteTreeWithAnnotations(aParams);
					}
				}

			}
		}

		return aContexts;
	};

	/**
	 * Simple request to count how many nodes are available in the collection, starting at the given rootLevel.
	 * Depending on the countMode of the binding, either a $count or a $inlinecount is sent.
	 */
	ODataTreeBinding.prototype._getCountForCollection = function () {

		if (!this.bHasTreeAnnotations || this.sOperationMode != OperationMode.Auto) {
			Log.error("The Count for the collection can only be retrieved with Hierarchy Annotations and in OperationMode.Auto.");
			return;
		}

		// create a request object for the data request
		var aParams = [];

		function _handleSuccess(oData) {

			// $inlinecount is in oData.__count, the $count is just oData
			var iCount = oData.__count ? parseInt(oData.__count) : parseInt(oData);

			this.iTotalCollectionCount = iCount;

			// in the OpertionMode.Auto, we check if the count is LE than the given threshold and set the client operation flag accordingly
			if (this.sOperationMode == OperationMode.Auto) {
				if (this.iTotalCollectionCount <= this.iThreshold) {
					this.bClientOperation = true;
					this.bThresholdRejected = false;
				} else {
					this.bClientOperation = false;
					this.bThresholdRejected = true;
				}
				this._fireChange({reason: ChangeReason.Change});
			}
		}

		function _handleError(oError) {
			// Only perform error handling if the request was not aborted intentionally
			if (oError && oError.statusCode === 0 && oError.statusText === "abort") {
				return;
			}
			var sErrorMsg = "Request for $count failed: " + oError.message;
			if (oError.response){
				sErrorMsg += ", " + oError.response.statusCode + ", " + oError.response.statusText + ", " + oError.response.body;
			}
			Log.warning(sErrorMsg);
		}

		var sAbsolutePath = this.oModel.resolve(this.getPath(), this.getContext());

		// default filter is on the rootLevel
		var sLevelFilter = "";
		if (this.iRootLevel > 0) {
			sLevelFilter = this._getLevelFilterParams("GE", this.getRootLevel());
		}

		// if necessary we add all other filters to the count request
		var sFilterParams = "";
		if (this.bUseServersideApplicationFilters) {
			var sFilterParams = this.getFilterParams();
		}

		//only build filter statement if necessary
		if (sLevelFilter || sFilterParams) {
			//if we have a level filter AND an application filter, we need to add an escaped "AND" to between
			if (sFilterParams && sLevelFilter) {
				sFilterParams = "%20and%20" + sFilterParams;
			}
			aParams.push("$filter=" + sLevelFilter + sFilterParams);
		}

		// figure out how to request the count
		var sCountType = "";
		if (this.sCountMode == CountMode.Request || this.sCountMode == CountMode.Both) {
			sCountType = "/$count";
		} else if (this.sCountMode == CountMode.Inline || this.sCountMode == CountMode.InlineRepeat) {
			aParams.push("$top=0");
			aParams.push("$inlinecount=allpages");
		}

		// send the counting request
		if (sAbsolutePath) {
			this.oModel.read(sAbsolutePath + sCountType, {
				urlParameters: aParams,
				success: _handleSuccess.bind(this),
				error: _handleError.bind(this),
				groupId: this.sRefreshGroupId ? this.sRefreshGroupId : this.sGroupId
			});
		}
	};

	/**
	 * Issues a $count request for the given node-id/odata-key.
	 * Only used when running in CountMode.Request. Inlinecounts are appended directly when issuing a loading request.
	 * @private
	 */
	ODataTreeBinding.prototype._getCountForNodeId = function(sNodeId, iStartIndex, iLength, iThreshold, mParameters) {
		var that = this,
			sGroupId;

		// create a request object for the data request
		var aParams = [];

		function _handleSuccess(oData) {
			that.oFinalLengths[sNodeId] = true;
			that.oLengths[sNodeId] = parseInt(oData);
		}

		function _handleError(oError) {
			//Only perform error handling if the request was not aborted intentionally
			if (oError && oError.statusCode === 0 && oError.statusText === "abort") {
				return;
			}
			var sErrorMsg = "Request for $count failed: " + oError.message;
			if (oError.response){
				sErrorMsg += ", " + oError.response.statusCode + ", " + oError.response.statusText + ", " + oError.response.body;
			}
			Log.warning(sErrorMsg);
		}

		var sAbsolutePath;

		var sFilterParams = this.getFilterParams() || "";
		var sNodeFilter = "";
		if (this.bHasTreeAnnotations) {
			//resolve OData-Key to hierarchy node property value for filtering
			var oNodeContext = this.oModel.getContext("/" + sNodeId);
			var sHierarchyNodeId = oNodeContext.getProperty(this.oTreeProperties["hierarchy-node-for"]);

			sAbsolutePath = this.oModel.resolve(this.getPath(), this.getContext());
			// only filter for the parent node if the given node is not the root (null)
			// if root and we $count the collection
			if (sNodeId != null) {
				sNodeFilter = this._getNodeFilterParams({id: sHierarchyNodeId});
			} else {
				sNodeFilter = this._getLevelFilterParams("EQ", this.getRootLevel());
			}

		} else {
			sAbsolutePath = sNodeId;
		}

		if (sNodeFilter || sFilterParams) {
			var sAnd = "";
			if (sNodeFilter && sFilterParams) {
				sAnd = "%20and%20";
			}

			sFilterParams = "$filter=" + sFilterParams + sAnd + sNodeFilter;
			aParams.push(sFilterParams);
		}

		// Only send request, if path is defined
		if (sAbsolutePath) {
			sGroupId = this.sRefreshGroupId ? this.sRefreshGroupId : this.sGroupId;
			this.oModel.read(sAbsolutePath + "/$count", {
				urlParameters: aParams,
				success: _handleSuccess,
				error: _handleError,
				sorters: this.aSorters,
				groupId: sGroupId
			});
		}
	};

	/**
	 * Retrieves parent ids from a given data set
	 *
	 * @param {Array} aData Lookup array to search for parent ids
	 * @param {Boolean} bExcludeRootNodes Can be set to exclude root node elements
	 * @returns {Array} Array of all parent ids
	 *
	 * @private
	 */
	ODataTreeBinding.prototype._getParentMap = function(aData) {
		var mParentKeys = {};

		for (var i = 0; i < aData.length; i++) {
			var sID = aData[i][this.oTreeProperties["hierarchy-node-for"]];
			if (mParentKeys[sID]) {
				Log.warning("ODataTreeBinding: Duplicate key: " + sID + "!");
			}
			mParentKeys[sID] = this.oModel._getKey(aData[i]);

		}

		return mParentKeys;
	};

	/**
	 * Creates key map for given data
	 *
	 * @param {Array} aData data which should be preprocessed
	 * @returns {Object<string,string[]>} Map of parent and child keys
	 *
	 * @private
	 */
	ODataTreeBinding.prototype._createKeyMap = function(aData, bSkipFirstNode) {
		if (aData && aData.length > 0) {
			var mParentsKeys = this._getParentMap(aData), mKeys = {};

			for (var i = bSkipFirstNode ? 1 : 0; i < aData.length; i++) {
				var sParentNodeID = aData[i][this.oTreeProperties["hierarchy-parent-node-for"]],
					sParentKey = mParentsKeys[sParentNodeID];

				if (parseInt(aData[i][this.oTreeProperties["hierarchy-level-for"]]) === this.iRootLevel) {
					sParentKey = "null";
				}

				if (!mKeys[sParentKey]) {
					mKeys[sParentKey] = [];
				}

				// add the current entry key to the key map, as a child of its parent node
				mKeys[sParentKey].push(this.oModel._getKey(aData[i]));
			}

			return mKeys;
		}
	};

	/**
	 * Should import the complete keys hierarchy.
	 *
	 * @param {Object<string,string[]>} mKeys Keys to add
	 *
	 * @private
	 */
	ODataTreeBinding.prototype._importCompleteKeysHierarchy = function (mKeys) {
		var iChildCount, sKey;
		for (sKey in mKeys) {
			iChildCount = mKeys[sKey].length || 0;
			this.oKeys[sKey] = mKeys[sKey];
			// update the length of the parent node
			this.oLengths[sKey] = iChildCount;
			this.oFinalLengths[sKey] = true;

			// keep up with the loaded sections
			this._mLoadedSections[sKey] = [ { startIndex: 0, length: iChildCount } ];
		}
	};

	/**
	 * Update node key in case if it changes
	 *
	 * @param {object} oNode
	 * @param {string} sNewKey
	 *
	 * @private
	 */
	ODataTreeBinding.prototype._updateNodeKey = function (oNode, sNewKey) {
		var sOldKey = this.oModel.getKey(oNode.context),
			sParentKey, nIndex;
		if (parseInt(oNode.context.getProperty(this.oTreeProperties["hierarchy-level-for"])) === this.iRootLevel) {
			sParentKey = "null";
		} else {
			sParentKey = this.oModel.getKey(oNode.parent.context);
		}

		nIndex = this.oKeys[sParentKey].indexOf(sOldKey);
		if (nIndex !== -1) {
			this.oKeys[sParentKey][nIndex] = sNewKey;
		} else {
			this.oKeys[sParentKey].push(sNewKey);
		}
	};

	/**
	 * Triggers backend requests to load the subtree of a given node
	 *
	 * @param {object} oNode Root node of the requested subtree
	 * @param {string[]} aParams OData URL parameters
	 * @return {Promise} A promise resolving once the data has been imported
	 *
	 * @private
	 */
	ODataTreeBinding.prototype._loadSubTree = function (oNode, aParams) {
		return new Promise(function (resolve, reject) {
			var sRequestKey, sGroupId, sAbsolutePath;

			// Prevent data from loading if no tree annotation is available
			if (!this.bHasTreeAnnotations) {
				reject(new Error("_loadSubTree: doesn't support hierarchies without tree annotations"));
				return;
			}

			sRequestKey = "loadSubTree-" + aParams.join("-");

			// Skip previous request
			if (this.mRequestHandles[sRequestKey]) {
				this.mRequestHandles[sRequestKey].abort();
			}

			var fnSuccess = function (oData) {
				// Collecting contexts
				// beware: oData.results can be an empty array -> so the length has to be checked
				if (oData.results.length > 0) {
					var sParentKey = this.oModel.getKey(oData.results[0]);
					this._updateNodeKey(oNode, sParentKey);
					var mKeys = this._createKeyMap(oData.results);
					this._importCompleteKeysHierarchy(mKeys);
				}

				delete this.mRequestHandles[sRequestKey];
				this.bNeedsUpdate = true;

				this.oModel.callAfterUpdate(function () {
					this.fireDataReceived({ data: oData });
				}.bind(this));

				resolve(oData);
			}.bind(this);

			var fnError = function (oError) {
				delete this.mRequestHandles[sRequestKey];

				//Only perform error handling if the request was not aborted intentionally
				if (oError && oError.statusCode === 0 && oError.statusText === "abort") {
					return;
				}

				this.fireDataReceived();

				reject(); // Application should retrieve error details via ODataModel events
			}.bind(this);


			// execute the request and use the metadata if available
			if (!this.bSkipDataEvents) {
				this.fireDataRequested();
			}
			this.bSkipDataEvents = false;

			sAbsolutePath = this.oModel.resolve(this.getPath(), this.getContext());
			if (sAbsolutePath) {
				sGroupId = this.sRefreshGroupId ? this.sRefreshGroupId : this.sGroupId;
				this.mRequestHandles[sRequestKey] = this.oModel.read(sAbsolutePath, {
					urlParameters: aParams,
					success: fnSuccess,
					error: fnError,
					sorters: this.aSorters,
					groupId: sGroupId
				});
			}
		}.bind(this));
	};

	/**
	 * Triggers backend requests to load the child nodes of the node with the given sNodeId.
	 *
	 * @param {string} sNodeId the value of the hierarchy node property on which a parent node filter will be performed
	 * @param {int} iStartIndex start index of the page
	 * @param {int} iLength length of the page
	 * @param {int} iThreshold additionally loaded entities
	 * @param {array} aParams OData URL parameters, already concatenated with "="
	 * @param {object} mParameters additional request parameters
	 * @param {object} mParameters.navPath the navigation path
	 *
	 * @return {sap.ui.model.Context[]} Array of contexts
	 *
	 * @private
	 */
	ODataTreeBinding.prototype._loadSubNodes = function(sNodeId, iStartIndex, iLength, iThreshold, aParams, mParameters, oRequestedSection) {
		var that = this,
			sGroupId,
			bInlineCountRequested = false;

		// Only append $skip/$top values if we run in OperationMode "Server".
		// When the OperationMode is set to "Client", we will fetch the whole collection
		if ((iStartIndex || iLength) && !this.bClientOperation) {
			aParams.push("$skip=" + iStartIndex + "&$top=" + (iLength + iThreshold));
		}

		//check if we already have a count
		if (!this.oFinalLengths[sNodeId] || this.sCountMode == CountMode.InlineRepeat) {
			// issue $inlinecount
			if (this.sCountMode == CountMode.Inline || this.sCountMode == CountMode.InlineRepeat || this.sCountMode == CountMode.Both) {
				aParams.push("$inlinecount=allpages");
				bInlineCountRequested = true;
			} else if (this.sCountMode == CountMode.Request) {
				//... or $count request
				that._getCountForNodeId(sNodeId);
			}
		}

		var sRequestKey = "" + sNodeId + "-" + iStartIndex + "-" + this._iPageSize + "-" + iThreshold;

		function fnSuccess(oData) {

			if (oData) {
				// make sure we have a keys array
				that.oKeys[sNodeId] = that.oKeys[sNodeId] || [];

				// evaluate the count
				if (bInlineCountRequested && oData.__count >= 0) {
					that.oLengths[sNodeId] = parseInt(oData.__count);
					that.oFinalLengths[sNodeId] = true;
				}
			}

			// Collecting contexts
			// beware: oData.results can be an empty array -> so the length has to be checked
			if (Array.isArray(oData.results) && oData.results.length > 0) {

				// Case 1: Result is an entity set
				// Case 1a: Tree Annotations
				if (that.bHasTreeAnnotations) {
					var mLastNodeIdIndices = {};

					for (var i = 0; i < oData.results.length; i++) {
						var oEntry = oData.results[i];

						if (i == 0) {
							mLastNodeIdIndices[sNodeId] = iStartIndex;
						} else if (mLastNodeIdIndices[sNodeId] == undefined) {
							mLastNodeIdIndices[sNodeId] = 0;
						}

						that.oKeys[sNodeId][mLastNodeIdIndices[sNodeId]] = that.oModel._getKey(oEntry);
						mLastNodeIdIndices[sNodeId]++;
					}
				} else {
					// Case 1b: Navigation Properties
					for (var i = 0; i < oData.results.length; i++) {
						var oEntry = oData.results[i];
						var sKey = that.oModel._getKey(oEntry);
						that._processODataObject(oEntry, "/" + sKey, mParameters.navPath);
						that.oKeys[sNodeId][i + iStartIndex] = sKey;
					}
				}
			} else if (oData && !Array.isArray(oData.results)){
				// Case 2: oData.results is not an array, so oData is a single entity
				// this only happens if you bind to a single entity as root element)
				that.oKeys[null] = that.oModel._getKey(oData);
				if (!that.bHasTreeAnnotations) {
					that._processODataObject(oData, sNodeId, mParameters.navPath);
				}
			}

			delete that.mRequestHandles[sRequestKey];
			that.bNeedsUpdate = true;

			that.oModel.callAfterUpdate(function() {
				that.fireDataReceived({data: oData});
			});
		}

		function fnError(oError) {
			//Only perform error handling if the request was not aborted intentionally
			if (oError && oError.statusCode === 0 && oError.statusText === "abort") {
				return;
			}

			that.fireDataReceived();
			delete that.mRequestHandles[sRequestKey];

			if (oRequestedSection) {
				// remove section from loadedSections so the data can be requested again.
				// this might be required when e.g. when the service was not available for a short time
				var aLoadedSections = [];
				for (var i = 0; i < that._mLoadedSections[sNodeId].length; i++) {
					var oCurrentSection = that._mLoadedSections[sNodeId][i];
					if (oRequestedSection.startIndex >= oCurrentSection.startIndex && oRequestedSection.startIndex + oRequestedSection.length <= oCurrentSection.startIndex + oCurrentSection.length) {
						// remove the section interval and maintain adapted sections. If start index and length are the same, ignore the section
						if (oRequestedSection.startIndex !== oCurrentSection.startIndex && oRequestedSection.length !== oCurrentSection.length) {
							aLoadedSections = TreeBindingUtils.mergeSections(aLoadedSections, {startIndex: oCurrentSection.startIndex, length: oRequestedSection.startIndex - oCurrentSection.startIndex});
							aLoadedSections = TreeBindingUtils.mergeSections(aLoadedSections, {startIndex: oRequestedSection.startIndex + oRequestedSection.length, length: (oCurrentSection.startIndex + oCurrentSection.length) - (oRequestedSection.startIndex + oRequestedSection.length)});
						}

					} else {
						aLoadedSections.push(oCurrentSection);
					}
				}
				that._mLoadedSections[sNodeId] = aLoadedSections;
			}
		}

		// !== because we use "null" as sNodeId in case the user only provided a root level
		if (sNodeId !== undefined) {
			// execute the request and use the metadata if available
			if (!this.bSkipDataEvents) {
				this.fireDataRequested();
			}
			this.bSkipDataEvents = false;

			var sAbsolutePath;
			if (this.bHasTreeAnnotations) {
				sAbsolutePath = this.oModel.resolve(this.getPath(), this.getContext());
			} else {
				sAbsolutePath = sNodeId;
			}

			if (this.mRequestHandles[sRequestKey]) {
				this.mRequestHandles[sRequestKey].abort();
			}
			if (sAbsolutePath) {
				sGroupId = this.sRefreshGroupId ? this.sRefreshGroupId : this.sGroupId;
				this.mRequestHandles[sRequestKey] = this.oModel.read(sAbsolutePath, {
					urlParameters: aParams,
					success: fnSuccess,
					error: fnError,
					sorters: this.aSorters,
					groupId: sGroupId
				});
			}
		}
	};

	ODataTreeBinding.REQUEST_KEY_CLIENT = "_OPERATIONMODE_CLIENT_TREE_LOADING";

	/**
	 * Loads the complete collection from the given binding path.
	 * The tree is then reconstructed from the response entries based on the properties with hierarchy annotations.
	 * Adds additional URL parameters.
	 */
	ODataTreeBinding.prototype._loadCompleteTreeWithAnnotations = function (aURLParams) {
		var that = this;

		var sRequestKey = ODataTreeBinding.REQUEST_KEY_CLIENT;

		var fnSuccess = function (oData) {

			// all nodes on root level -> save in this.oKeys[null] = [] (?)
			if (oData.results && oData.results.length > 0) {

				//collect mapping table between parent node id and actual OData-Key
				var mParentIds = {};
				var oDataObj;
				for (var k = 0; k < oData.results.length; k++) {
					oDataObj = oData.results[k];
					var sDataKey = oDataObj[that.oTreeProperties["hierarchy-node-for"]];
					// sanity check: if we have duplicate keys, the data is messed up. Has already happend...
					if (mParentIds[sDataKey]) {
						Log.warning("ODataTreeBinding - Duplicate data entry for key: " + sDataKey + "!");
					}
					mParentIds[sDataKey] = that.oModel._getKey(oDataObj);
				}

				// process data and built tree
				for (var i = 0; i < oData.results.length; i++) {
					oDataObj = oData.results[i];
					var sParentNodeId = oDataObj[that.oTreeProperties["hierarchy-parent-node-for"]];
					var sParentKey = mParentIds[sParentNodeId]; //oDataObj[that.oTreeProperties["hierarchy-parent-node-for"]];

					// the parentNodeID for root nodes (node level == iRootLevel) is "null"
					if (parseInt(oDataObj[that.oTreeProperties["hierarchy-level-for"]]) === that.iRootLevel) {
						sParentKey = "null";
					}

					// make sure the parent node is already present in the key map
					that.oKeys[sParentKey] = that.oKeys[sParentKey] || [];

					// add the current entry key to the key map, as a child of its parent node
					var sKey = that.oModel._getKey(oDataObj);
					that.oKeys[sParentKey].push(sKey);

					// update the length of the parent node
					that.oLengths[sParentKey] = that.oLengths[sParentKey] || 0;
					that.oLengths[sParentKey]++;
					that.oFinalLengths[sParentKey] = true;

					// keep up with the loaded sections
					that._mLoadedSections[sParentKey] = that._mLoadedSections[sParentKey] || [];
					that._mLoadedSections[sParentKey][0] = that._mLoadedSections[sParentKey][0] || {startIndex: 0, length: 0};
					that._mLoadedSections[sParentKey][0].length++;
				}

			} else {
				// no data received -> empty tree
				that.oKeys["null"] = [];
				that.oLengths["null"] = 0;
				that.oFinalLengths["null"] = true;
			}

			that.oAllKeys = jQuery.extend(true, {}, that.oKeys);
			that.oAllLengths = jQuery.extend(true, {}, that.oLengths);
			that.oAllFinalLengths = jQuery.extend(true, {}, that.oFinalLengths);

			delete that.mRequestHandles[sRequestKey];
			that.bNeedsUpdate = true;

			// apply clientside filters, if any
			if ((that.aApplicationFilters && that.aApplicationFilters.length > 0) ||
				(that.aFilters && that.aFilters.length > 0)) {
				that._applyFilter();
			}

			// apply clientside sorters
			if (that.aSorters && that.aSorters.length > 0) {
				that._applySort();
			}

			that.oModel.callAfterUpdate(function() {
				that.fireDataReceived({data: oData});
			});
		};

		var fnError = function (oError) {
			delete that.mRequestHandles[sRequestKey];

			// handle error state like the ListBinding -> reset data and trigger update
			var bAborted = oError.statusCode == 0;
			if (!bAborted) {
				that.oKeys = {};
				that.oLengths = {};
				that.oFinalLengths = {};
				that.oAllKeys = {};
				that.oAllLengths = {};
				that.oAllFinalLengths = {};
				that._fireChange({reason: ChangeReason.Change});
				that.fireDataReceived();
			}
		};

		// request the tree collection
		if (!this.bSkipDataEvents) {
			this.fireDataRequested();
		}
		this.bSkipDataEvents = false;

		if (this.mRequestHandles[sRequestKey]) {
			this.mRequestHandles[sRequestKey].abort();
		}
		var sAbsolutePath = this.oModel.resolve(this.getPath(), this.getContext());
		if (sAbsolutePath) {
			this.mRequestHandles[sRequestKey] = this.oModel.read(sAbsolutePath, {
				urlParameters: aURLPa