Exception on DataSource.load with force reload

[Blama]

Hi Isomorphic,

I have a Datasource, only relevant for the Admin and of course with declarative security, I don't need very often and I don't want to load on startup via the DataSourceLoader call from my HTML.
So I load it when I need it. but the forced reload of it fails or at least throws an exception in the Developer Console. Now I could not load it if it is already there, but I think it is an issue anyway, because there might be legitimate reasons to reload a DS.

On "Reload" click (OK):
WARN:DataSource:DataSource(s) already loaded: employees
Use forceReload to reload such DataSources

On "Force Reload" click (not OK):
WARN:Log:ID 'employees' for object '[DataSource ID:employees]' collides with the ID of an existing object. This can occur when the specified ID for a new SmartClient Canvas is the same as a native attribute of 'window', or another variable already assigned in global scope. The global reference to this object will be replaced. Consider instead using a different ID to avoid this collision altogether, especially if the colliding ID is a native attribute of window. Replacing such objects often has serious and unintended consequences. In this case, the current value of window['employees'] is:

DataSource{testFileName: "/examples/shared/ds/test_data/employees...."[48],
titleField: "Name",
allowAdvancedCriteria: true,
tableCode: "a6744ab162eb640344ffc18c778b303d",
xmlns: "lmscompany/ds",
recordName: "employee",
serverType: "sql",
useAnsiJoins: true,
operationBindings: Array[1],
ID: "employees",
fields: Obj,
canQueueRequests: true,
name: "employees",
}

BuiltInDS.java (tested with v10.1p_2017-08-20):

package com.smartgwt.sample.client;

import com.google.gwt.core.client.EntryPoint;
import com.smartgwt.client.Version;
import com.smartgwt.client.core.KeyIdentifier;
import com.smartgwt.client.data.DataSource;
import com.smartgwt.client.util.Page;
import com.smartgwt.client.util.PageKeyHandler;
import com.smartgwt.client.util.SC;
import com.smartgwt.client.widgets.IButton;
import com.smartgwt.client.widgets.Window;
import com.smartgwt.client.widgets.events.ClickEvent;
import com.smartgwt.client.widgets.events.ClickHandler;
import com.smartgwt.client.widgets.layout.VLayout;

public class BuiltInDS extends VLayout implements EntryPoint {
    private IButton recreateBtn;

    public void onModuleLoad() {
        KeyIdentifier debugKey = new KeyIdentifier();
        debugKey.setCtrlKey(true);
        debugKey.setKeyName("D");

        Page.registerKey(debugKey, new PageKeyHandler() {
            public void execute(String keyName) {
                SC.showConsole();
            }
        });

        setWidth100();
        setHeight100();

        recreateBtn = new IButton("Recreate");
        recreateBtn.addClickHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent event) {
                new MyWindow().show();
            }
        });
        addMember(recreateBtn);
        new MyWindow().show();
        draw();
    }

    private class MyWindow extends Window {
        public MyWindow() {
            setWidth("95%");
            setHeight("95%");
            setMembersMargin(0);
            setModalMaskOpacity(70);
            setTitle(" (" + Version.getVersion() + "/" + Version.getSCVersionNumber() + ")");
            setTitle("DataSource force reload problem" + getTitle());
            setShowMinimizeButton(false);
            setIsModal(true);
            setShowModalMask(true);
            centerInPage();

            IButton reloadButton = new IButton("Reload");
            reloadButton.addClickHandler(new ClickHandler() {
                @Override
                public void onClick(ClickEvent event) {
                    DataSource.load("employees", null, false);
                }
            });
            addItem(reloadButton);

            IButton reloadForceButton = new IButton("Force Reload");
            reloadForceButton.addClickHandler(new ClickHandler() {
                @Override
                public void onClick(ClickEvent event) {
                    DataSource.load("employees", null, true);
                }
            });
            addItem(reloadForceButton);
        }
    }
}

Best regards
Blama

[Isomorphic]

To properly do a forceReload and avoid this warning, destroy() the old DataSource first (and any components using it).

[Blama]

Hi Isomorphic,

you are correct, it is working like this. But what is the purpose of the forceReload parameter then?

Best regards
Blama

[Isomorphic]

It causes clobbering of the existing DataSource rather than just avoiding the duplicate load.