/// <summary> /// Returns the next reference. /// </summary> /// <returns>The next reference that meets the browse criteria.</returns> public override IReference Next() { ComDaClientManager system = (ComDaClientManager)this.SystemContext.SystemHandle; ComDaClient client = system.SelectClient((ServerSystemContext)SystemContext); lock (DataLock) { IReference reference = null; // enumerate pre-defined references. // always call first to ensure any pushed-back references are returned first. reference = base.Next(); if (reference != null) { return(reference); } // don't start browsing huge number of references when only internal references are requested. if (InternalOnly) { return(null); } // fetch references from the server. do { // fetch next reference. reference = NextChild(); if (reference != null) { return(reference); } // go to the next stage. NextStage(); }while (m_stage != Stage.Done); // all done. return(null); } }
/// <summary> /// Returns the next child. /// </summary> private IReference NextChild() { ComDaClientManager system = (ComDaClientManager)this.SystemContext.SystemHandle; ComDaClient client = system.SelectClient((ServerSystemContext)SystemContext); // check if a specific browse name is requested. if (QualifiedName.IsNull(base.BrowseName)) { return(NextChild(m_stage)); } // keep fetching references until a matching browse name if found. NodeStateReference reference = null; do { reference = NextChild(m_stage); if (reference != null) { // need to let the caller look up the browse name. if (reference.Target == null) { return(reference); } // check for browse name match. if (reference.Target.BrowseName == base.BrowseName) { return(reference); } } }while (reference != null); // no match - need to go onto the next stage. return(null); }
/// <summary> /// Initializes the next stage of browsing. /// </summary> private void NextStage() { ComDaClientManager system = (ComDaClientManager)this.SystemContext.SystemHandle; ComDaClient client = system.SelectClient((ServerSystemContext)SystemContext); // determine which stage is next based on the reference types requested. for (Stage next = m_stage + 1; next <= Stage.Done; next++) { if (next == Stage.Children) { if (IsRequired(ReferenceTypeIds.Organizes, false)) { m_stage = next; break; } } else if (next == Stage.Properties) { if (IsRequired(ReferenceTypeIds.HasProperty, false)) { m_stage = next; break; } } else if (next == Stage.Parents) { if (IsRequired(ReferenceTypeIds.Organizes, true)) { m_stage = next; break; } } else if (next == Stage.Done) { m_stage = next; break; } } m_position = 0; // start enumerating branches. if (m_stage == Stage.Children) { m_browser = client.CreateBrowser(m_itemId); return; } // start enumerating properties. if (m_stage == Stage.Properties) { m_properties = client.ReadAvailableProperties(m_itemId, true); m_position = 0; return; } // start enumerating parents. if (m_stage == Stage.Parents) { m_parentId = client.FindElementParentId(m_itemId); return; } // all done. }
/// <summary> /// Returns the next child. /// </summary> private NodeStateReference NextChild(Stage stage) { ComDaClientManager system = (ComDaClientManager)this.SystemContext.SystemHandle; ComDaClient client = system.SelectClient((ServerSystemContext)SystemContext); DaElement element = null; if (stage == Stage.Children) { if (m_browser == null) { return(null); } element = m_browser.Next(); if (element == null) { return(null); } // construct the node. NodeState node = ModelUtils.ConstructElement(SystemContext, element, m_namespaceIndex); // return the reference. return(new NodeStateReference(ReferenceTypeIds.Organizes, false, node)); } if (stage == Stage.Properties) { if (m_properties == null) { return(null); } for (int ii = m_position; ii < m_properties.Length; ii++) { if (m_properties[ii].PropertyId <= PropertyIds.TimeZone) { continue; } m_position = ii + 1; // construct the node. NodeState node = ModelUtils.ConstructProperty(SystemContext, m_itemId, m_properties[ii], m_namespaceIndex); // return the reference. return(new NodeStateReference(ReferenceTypeIds.HasProperty, false, node)); } // all done. return(null); } if (stage == Stage.Parents) { if (m_parentId != null) { NodeId parentId = ModelUtils.ConstructIdForDaElement(m_parentId, -1, m_namespaceIndex); m_parentId = null; return(new NodeStateReference(ReferenceTypeIds.Organizes, true, parentId)); } } return(null); }