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**ex70375** · 6 Mar 2014, 14:20

hi blama,

did you get any advice or best practice from Isomorphic? I have to add the same functionality in my application next week and I've just asked myself the same questions.

best regards,
mirko

**Isomorphic** · 6 Mar 2014, 14:50

For the least duplicated work, don't draw() the ListGrid until you've applied all the *State variables.

Clearly you also should not fetch before applying all *State variables, since the sort direction changing would cause a re-fetch, as could some other field settings (like optionDataSource).

**Blama** · 7 Mar 2014, 02:57

Hi mirko,

what I do is to cache the ListGrid settings for the current user at startup (where I show no ListGrid, yet).
Then I use this:

Code:

public class Mylist extends ListGridVS {
	public LeadlistMyLeads() {
		// TODO: ggf. GroupState -> true, (wait for fix: http://forums.smartclient.com/showthread.php?t=29462)
		// Last 5 parameters: Selected-, Field-, Sort-, Hilite-, Group-State
		super("Mylist", false, true, true, false, false);
		setDataSource( ... );
		setAutoFetchData(false);
		setShowFilterEditor(true);
		setGroupByMaxRecords(200);
		setGroupStartOpen(GroupStartOpen.ALL);
		setCanGroupBy(true);

		// many field definitions
		
		setHilites(new Hilite[] { ... }); // NOT persisting, see super()
		setGroupByField( ... ); // NOT persisting, see super()
		setFields( ... );

		if (!viewStateHelper.applySavedViewStates()) {
			setSort(new SortSpecifier[] { ... });
		}
		fetchData(null, new ListGridIsLoadedCallBack(viewStateHelper));
	};
}

ListGridVS.java:

Code:

public abstract class ListGridVS extends ListGrid {
	final protected DataSource viewstateDS = DataSource.get(DatasourceEnum.T_VIEWSTATE.getValue());
	final protected ViewStateHelper viewStateHelper;

	public ListGridVS(String listGridObjectName) {
		super();
		this.viewStateHelper = new ViewStateHelper(listGridObjectName, this, false, true, true, false, true);
		setListGridObjectName(listGridObjectName);
		configure();
	}

	public ListGridVS(String listGridObjectName, boolean configureSelectedState, boolean configureFieldState, boolean configureSortState,
			boolean configureHiliteState, boolean configureGroupState) {
		super();
		this.viewStateHelper = new ViewStateHelper(listGridObjectName, this, configureSelectedState, configureFieldState, configureSortState,
				configureHiliteState, configureGroupState);
		setListGridObjectName(listGridObjectName);
		configure();
	}

	private void configure() {
		addViewStateChangedHandler(new ViewStateChangedHandler() {
			@Override
			public void onViewStateChanged(ViewStateChangedEvent event) {
				viewStateHelper.saveViewState();
			}
		});
	}

	public String getListGridObjectName() {
		return viewStateHelper.getObjectName();
	}

	public void setListGridObjectName(String listGridObjectName) {
		viewStateHelper.setObjectName(listGridObjectName);
		viewStateHelper.setSaveSettingsFromNowOn(false);
	}

	public class ListGridIsLoadedCallBack implements DSCallback {
		ViewStateHelper viewStateHelper;

		public ListGridIsLoadedCallBack(ViewStateHelper viewStateHelper) {
			super();
			this.viewStateHelper = viewStateHelper;
		}

		@Override
		public void execute(DSResponse dsResponse, Object data, DSRequest dsRequest) {
			this.viewStateHelper.setSaveSettingsFromNowOn(true);
		}
	};
}

ViewStateHelper.java:

Code:

public class ViewStateHelper {
	public static final String NO_UPDATE = "<NOUPDATE>";
	private boolean saveSettingsFromNowOn = false;
	private String objectName;
	private ListGrid listgrid;
	private boolean configureSelectedState;
	private boolean configureFieldState;
	private boolean configureSortState;
	private boolean configureHiliteState;
	private boolean configureGroupState;

	// Persisted settings
	private ViewStates viewStates;

	public ViewStateHelper(String objectName, ListGrid listgrid, boolean configureSelectedState, boolean configureFieldState,
			boolean configureSortState, boolean configureHiliteState, boolean configureGroupState) {
		this.objectName = objectName;
		this.viewStates = SettingsCache.getInstance().getViewState(objectName);
		this.listgrid = listgrid;
		this.configureSelectedState = configureSelectedState;
		this.configureFieldState = configureFieldState;
		this.configureSortState = configureSortState;
		this.configureHiliteState = configureHiliteState;
		this.configureGroupState = configureGroupState;
	}

	public boolean hasSavedViewStates() {
		return viewStates != null;
	}

	public String getObjectName() {
		return objectName;
	}

	public void setObjectName(String objectName) {
		this.objectName = objectName;
		this.viewStates = SettingsCache.getInstance().getViewState(objectName);
	}

	public void saveViewState() {
		if (saveSettingsFromNowOn) {
			String curSelectedState = (configureSelectedState && (viewStates == null || !listgrid.getSelectedState().equals(
					viewStates.getSelectedState()))) ? listgrid.getSelectedState() : NO_UPDATE;
			String curFieldState = (configureFieldState && (viewStates == null || !listgrid.getFieldState().equals(viewStates.getFieldState()))) ? listgrid
					.getFieldState() : NO_UPDATE;
			String curSortState = (configureSortState && (viewStates == null || !listgrid.getSortState().equals(viewStates.getSortState()))) ? listgrid
					.getSortState() : NO_UPDATE;
			String curHiliteState = (configureHiliteState && (viewStates == null || !listgrid.getHiliteState()
					.equals(viewStates.getHiliteState()))) ? listgrid.getHiliteState() : NO_UPDATE;
			String curGroupState = (configureGroupState && (viewStates == null || !listgrid.getGroupState().equals(viewStates.getGroupState()))) ? listgrid
					.getGroupState() : NO_UPDATE;

			if ((configureSelectedState && !curSelectedState.equals(NO_UPDATE)) || (configureFieldState && !curFieldState.equals(NO_UPDATE))
					|| (configureSortState && !curSortState.equals(NO_UPDATE)) || (configureHiliteState && !curHiliteState.equals(NO_UPDATE))
					|| (configureGroupState && !curGroupState.equals(NO_UPDATE))) {
				// Send new values. NO_UPDATE will be handled here.
				SettingsCache.getInstance().setViewStates(objectName, curSelectedState, curFieldState, curSortState, curHiliteState, curGroupState);
				// Set current saved settings to current in order to recognize the next change
				viewStates = new ViewStates(listgrid.getSelectedState(), listgrid.getFieldState(), listgrid.getSortState(),
						listgrid.getHiliteState(), listgrid.getGroupState());
			}
		}
	}

	public boolean applySavedViewStates() {
		if (viewStates != null) {
			if (configureSelectedState && viewStates.getSelectedState() != null)
				listgrid.setSelectedState(viewStates.getSelectedState());
			if (configureFieldState && viewStates.getFieldState() != null)
				listgrid.setFieldState(viewStates.getFieldState());
			if (configureHiliteState && viewStates.getHiliteState() != null)
				listgrid.setHiliteState(viewStates.getHiliteState());
			if (configureGroupState && viewStates.getGroupState() != null)
				listgrid.setGroupState(viewStates.getGroupState());

			//See http://forums.smartclient.com/showthread.php?p=116180#post116180 for the order of calls
			if (configureSortState && viewStates.getSortState() != null)
				listgrid.setSortState(viewStates.getSortState());
			return true;
		}
		return false;
	}

	public void setSaveSettingsFromNowOn(boolean saveSettingsFromNowOn) {
		this.saveSettingsFromNowOn = saveSettingsFromNowOn;
	}
}

As my settingsCache has the settings when constructing the grid, I see no visual glitches (no roundtrip delay for the fetch), although they might still be there.

@Isomorphic:
I never draw() anything. My normal pseudocode flow is:

Code:

VLayout vL = new VLayout(){
{
	ListGridSubclass lgs = new ListGridSubclass();
	// This includes either a fetch at the end or is setAutoFetch(true)
	addMember(lgs);
}};
...

Is there a way in this setup where I can make sure that a Grid is only shown when the design is finished with respect to shown fields. The data may still be missing.

Thank you & best regards,
Blama

**ex70375** · 8 Apr 2014, 06:37

Hi Blama,

first of all. many thanks for sharing your work!!! This saves me a lot of time.

May I ask you to publish the class ViewStates and SettingsCache . :-)
How is the design of your viewstate database table? How did you define the fields.

Cheers Mirko

P.S.: I am also from Munich. maybe we can even meet or communicate via email.

**Blama** · 8 Apr 2014, 07:24

Hi Mirko,

the code is as follows:

ViewStates.java:

Code:

import a.b.c.d.ViewStateHelper;

public class ViewStates {
	private String selectedState = null;
	private String fieldState = null;
	private String sortState = null;
	private String hiliteState = null;
	private String groupState = null;

	public ViewStates(String selectedState, String fieldState, String sortState, String hiliteState, String groupState) {
		if (!ViewStateHelper.NO_UPDATE.equals(selectedState))
			this.selectedState = selectedState;
		if (!ViewStateHelper.NO_UPDATE.equals(fieldState))
			this.fieldState = fieldState;
		if (!ViewStateHelper.NO_UPDATE.equals(sortState))
			this.sortState = sortState;
		if (!ViewStateHelper.NO_UPDATE.equals(hiliteState))
			this.hiliteState = hiliteState;
		if (!ViewStateHelper.NO_UPDATE.equals(groupState))
			this.groupState = groupState;
	}

	public String getSelectedState() {
		return selectedState;
	}

	public String getFieldState() {
		return fieldState;
	}

	public String getSortState() {
		return sortState;
	}

	public String getHiliteState() {
		return hiliteState;
	}

	public String getGroupState() {
		return groupState;
	}

	public void setSelectedState(String selectedState) {
		this.selectedState = selectedState;
	}

	public void setFieldState(String fieldState) {
		this.fieldState = fieldState;
	}

	public void setSortState(String sortState) {
		this.sortState = sortState;
	}

	public void setHiliteState(String hiliteState) {
		this.hiliteState = hiliteState;
	}

	public void setGroupState(String groupState) {
		this.groupState = groupState;
	}
}

stripped version of SettingsCache.java:

Code:

public class SettingsCache2 {
	private static SettingsCache2 instance = new SettingsCache2();
	private Map<String, ViewStates> viewStatesMap = new HashMap<String, ViewStates>();
	final private DataSource viewstateDS = DataSource.get(DatasourceEnum.T_VIEWSTATE.getValue());

	private SettingsCache2() {
		refresh();
	}

	public static SettingsCache2 getInstance() {
		return instance;
	}

	public void refresh() {
		// ViewStates caching:
		viewstateDS.fetchData(new AdvancedCriteria("USER_ID", OperatorId.EQUALS, User.getUserId()), new DSCallback() {
			@Override
			public void execute(DSResponse dsResponse, Object data, DSRequest dsRequest) {
				if (dsResponse != null && dsResponse.getStatus() == RPCResponse.STATUS_SUCCESS) {
					for (Record r : dsResponse.getData()) {
						ViewStates vs = new ViewStates(r.getAttribute("SELECTEDSTATE"), r.getAttribute("FIELDSTATE"), r.getAttribute("SORTSTATE"), r
								.getAttribute("HILITESTATE"), r.getAttribute("GROUPSTATE"));
						viewStatesMap.put(r.getAttribute("OBJECT"), vs);
					}
				}
			}
		}, new DSRequest(DSOperationType.FETCH) {
			{
				setProgressiveLoading(true);
			}
		});
	}

	public ViewStates getViewState(String objectName) {
		return viewStatesMap.get(objectName);
	}

	public String getSelectedState(String objectName) {
		if (!viewStatesMap.containsKey(objectName))
			return null;
		else
			return viewStatesMap.get(objectName).getSelectedState();
	}

	public String getFieldState(String objectName) {
		if (!viewStatesMap.containsKey(objectName))
			return null;
		else
			return viewStatesMap.get(objectName).getFieldState();
	}

	public String getSortState(String objectName) {
		if (!viewStatesMap.containsKey(objectName))
			return null;
		else
			return viewStatesMap.get(objectName).getSortState();
	}

	public String getHiliteState(String objectName) {
		if (!viewStatesMap.containsKey(objectName))
			return null;
		else
			return viewStatesMap.get(objectName).getHiliteState();
	}

	public String getGroupState(String objectName) {
		if (!viewStatesMap.containsKey(objectName))
			return null;
		else
			return viewStatesMap.get(objectName).getGroupState();
	}

	public void setViewStates(final String objectName, final String curSelectedState, final String curFieldState, final String curSortState,
			final String curHiliteState, final String curGroupState) {
		Record updatedRecord = new Record();
		updatedRecord.setAttribute("USER_ID", User.getUserId());
		updatedRecord.setAttribute("OBJECT", objectName);

		if (!ViewStateHelper.NO_UPDATE.equals(curSelectedState))
			updatedRecord.setAttribute("SELECTEDSTATE", curSelectedState);
		if (!ViewStateHelper.NO_UPDATE.equals(curFieldState))
			updatedRecord.setAttribute("FIELDSTATE", curFieldState);
		if (!ViewStateHelper.NO_UPDATE.equals(curSortState))
			updatedRecord.setAttribute("SORTSTATE", curSortState);
		if (!ViewStateHelper.NO_UPDATE.equals(curHiliteState))
			updatedRecord.setAttribute("HILITESTATE", curHiliteState);
		if (!ViewStateHelper.NO_UPDATE.equals(curGroupState))
			updatedRecord.setAttribute("GROUPSTATE", curGroupState);

		viewstateDS.updateData(updatedRecord, new DSCallback() {
			@Override
			public void execute(DSResponse dsResponse, Object data, DSRequest dsRequest) {
				if (Helper.isSuccess(dsResponse)) {
					if (viewStatesMap.containsKey(objectName)) {
						ViewStates vs = viewStatesMap.get(objectName);
						if (!ViewStateHelper.NO_UPDATE.equals(curSelectedState))
							vs.setSelectedState(curSelectedState);
						if (!ViewStateHelper.NO_UPDATE.equals(curFieldState))
							vs.setFieldState(curFieldState);
						if (!ViewStateHelper.NO_UPDATE.equals(curSortState))
							vs.setSortState(curSortState);
						if (!ViewStateHelper.NO_UPDATE.equals(curHiliteState))
							vs.setHiliteState(curHiliteState);
						if (!ViewStateHelper.NO_UPDATE.equals(curGroupState))
							vs.setGroupState(curGroupState);
						viewStatesMap.put(objectName, vs);
					} else {
						ViewStates vs = new ViewStates(curSelectedState, curFieldState, curSortState, curHiliteState, curGroupState);
						viewStatesMap.put(objectName, vs);
					}
				}
			}
		});
	}
}

T_VIEWSTATE.ds.xml:

Code:

<DataSource dbName="Oracle" tableName="T_VIEWSTATE" ID="T_VIEWSTATE" serverType="sql"
	defaultTextMatchStyle="exactCase">
	<fields>
		<field primaryKey="true" name="USER_ID" type="integer" required="true" />
		<field primaryKey="true" name="OBJECT" length="30" type="text" escapeHTML="true" required="true" />

		<field foreignKey="V_USER_CREATED_BY.ID" name="CREATED_BY" title="Erstellt von" type="creator" />
		<field name="CREATED_AT" title="Erstellt am" type="creatorTimestamp" />
		<field foreignKey="V_USER_MODIFIED_BY.ID" name="MODIFIED_BY" title="Ge�ndert von" type="modifier" />
		<field name="MODIFIED_AT" title="Ge�ndert am" type="modifierTimestamp" />

		<field name="SELECTEDSTATE" length="1500" type="text" escapeHTML="true" />
		<field name="FIELDSTATE" length="2000" type="text" escapeHTML="true" />
		<field name="SORTSTATE" length="1000" type="text" escapeHTML="true" />
		<field name="HILITESTATE" length="1500" type="text" escapeHTML="true" />
		<field name="GROUPSTATE" length="1000" type="text" escapeHTML="true" />
	</fields>
	<serverObject lookupStyle="new" className="server.worker.T_VIEWSTATE" />
	<operationBindings>
		<operationBinding operationType="fetch" outputs="OBJECT, SELECTEDSTATE, FIELDSTATE, SORTSTATE, HILITESTATE, GROUPSTATE" />
		<operationBinding operationType="update" canSyncCache="false" />
		<operationBinding operationType="add" requiresRole="updateOnly" />
		<operationBinding operationType="remove" requiresRole="noRemove" />
	</operationBindings>
</DataSource>

T_VIEWSTATE.java:

Code:

public class T_VIEWSTATE {

	public DSResponse fetch(DSRequest dsRequest, HttpServletRequest servletRequest) throws Exception {
		dsRequest.addToCriteria("USER_ID", DefaultOperators.Equals, User.getUserId(servletRequest));
		return dsRequest.execute();
	}

	public DSResponse add(DSRequest dsRequest, HttpServletRequest servletRequest) throws Exception {
		return dsRequest.execute();
	}

	public DSResponse update(DSRequest dsRequest, HttpServletRequest servletRequest) throws Exception {
		@SuppressWarnings({ "unchecked", "unused" })
		Map<String, Object> critMap = dsRequest.getCriteria();
		@SuppressWarnings("unchecked")
		Map<String, Object> valueMap = dsRequest.getValues();
		valueMap.put("USER_ID", User.getUserId(servletRequest));
		dsRequest.setValues(valueMap);
		//TODO: Testcase: Generates exception
//		dsRequest.addToCriteria("USER_ID", DefaultOperators.Equals, User.getUserId(servletRequest));
		if (dsRequest.getCriteriaValue("OBJECT") == null)
			return new DSResponse(dsRequest.getDataSource()).setOperationType(DataSource.OP_UPDATE).setFailure("Please specify the component you want to update the settings for.");

//		dsRequest.setAllowMultiUpdate(true);
		DSResponse updateResp = dsRequest.execute();
		if (Helper.oneRow(updateResp))
			return updateResp;
		else if (Helper.zeroRows(updateResp)) {
			DSRequest addReq = new DSRequest(DatasourceEnum.T_VIEWSTATE.getValue(), DataSource.OP_ADD, dsRequest.getRPCManager());
			addReq.setValues(valueMap);
			
			DSResponse addResp = addReq.execute();
			if (Helper.oneRow(addResp)) {
				addResp.setOperationType(DataSource.OP_UPDATE);
				return addResp;
			}
		}
		return new DSResponse().setFailure("There was some error updating the viewstate.");
	};
};

CREATE TABLE:

Code:

DROP SEQUENCE t_viewstate_id ;
CREATE TABLE t_viewstate
  (
    id            INTEGER CONSTRAINT NNC_viewstate_id NOT NULL ,
    tenant_id     INTEGER CONSTRAINT NNC_viewstate_tenant_id NOT NULL ,
    user_id       INTEGER CONSTRAINT NNC_viewstate_user_id NOT NULL ,
    object        VARCHAR2 (30 CHAR) CONSTRAINT NNC_viewstate_object NOT NULL ,
    selectedstate VARCHAR2 (1500 CHAR) ,
    fieldstate    VARCHAR2 (2000 CHAR) ,
    sortstate     VARCHAR2 (1000 CHAR) ,
    hilitestate   VARCHAR2 (1500 CHAR) ,
    groupstate    VARCHAR2 (1000 CHAR) ,
    created_by    INTEGER CONSTRAINT NNC_viewstate_creaby NOT NULL ,
    created_at    DATE DEFAULT SYSDATE CONSTRAINT NNC_viewstate_creaat NOT NULL ,
    modified_by   INTEGER CONSTRAINT NNC_viewstate_modby NOT NULL ,
    modified_at   DATE DEFAULT SYSDATE CONSTRAINT NNC_viewstate_modat NOT NULL
  ) ;
COMMENT ON TABLE t_viewstate
IS
  'Persists the viewstate of ListGrids in the application.' ;
  ALTER TABLE t_viewstate ADD CONSTRAINT PK_viewstate PRIMARY KEY ( tenant_id, id ) ;
  ALTER TABLE t_viewstate ADD CONSTRAINT UC_viewstate_user_object UNIQUE ( user_id , object ) ;
  ALTER TABLE t_viewstate ADD CONSTRAINT FK_viewstate_user FOREIGN KEY ( tenant_id, user_id ) REFERENCES t_user ( tenant_id, id ) ;
CREATE SEQUENCE t_viewstate_ID START WITH 1 NOCACHE ORDER ;
CREATE OR REPLACE TRIGGER t_viewstate_B_I_R BEFORE
  INSERT ON t_viewstate FOR EACH ROW WHEN (NEW.id IS NULL) BEGIN :NEW.id := t_viewstate_ID.NEXTVAL;
END;
/

I'd like a "Munich SmartGWT User Group Meeting" very much. Please mail me at blama@gmx.net.

Best regards,
Blama

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Best practice needed: ListGrid with setViewState(...)

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