SmartGWT combines large dataset handling with adaptive use of client-side sort (Smart GWT) : DataSource « GWT « Java
SmartGWT combines large dataset handling with adaptive use of client-side sort (Smart GWT)
/*
* SmartGWT (GWT for SmartClient)
* Copyright 2008 and beyond, Isomorphic Software, Inc.
*
* SmartGWT is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License version 3
* as published by the Free Software Foundation. SmartGWT is also
* available under typical commercial license terms - see
* http://smartclient.com/license
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package com.smartgwt.sample.showcase.client;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.ui.RootPanel;
import com.smartgwt.client.data.Criteria;
import com.smartgwt.client.data.DSRequest;
import com.smartgwt.client.data.DSResponse;
import com.smartgwt.client.data.DataSource;
import com.smartgwt.client.data.fields.DataSourceBooleanField;
import com.smartgwt.client.data.fields.DataSourceDateField;
import com.smartgwt.client.data.fields.DataSourceEnumField;
import com.smartgwt.client.data.fields.DataSourceFloatField;
import com.smartgwt.client.data.fields.DataSourceIntegerField;
import com.smartgwt.client.data.fields.DataSourceLinkField;
import com.smartgwt.client.data.fields.DataSourceTextField;
import com.smartgwt.client.util.SC;
import com.smartgwt.client.widgets.Canvas;
import com.smartgwt.client.widgets.Label;
import com.smartgwt.client.widgets.form.DynamicForm;
import com.smartgwt.client.widgets.form.fields.CheckboxItem;
import com.smartgwt.client.widgets.form.fields.events.ChangedEvent;
import com.smartgwt.client.widgets.form.fields.events.ChangedHandler;
import com.smartgwt.client.widgets.form.validator.FloatPrecisionValidator;
import com.smartgwt.client.widgets.form.validator.FloatRangeValidator;
import com.smartgwt.client.widgets.grid.ListGrid;
import com.smartgwt.client.widgets.grid.ListGridField;
public class Showcase implements EntryPoint {
public void onModuleLoad() {
RootPanel.get().add(getViewPanel());
}
public Canvas getViewPanel() {
Canvas canvas = new Canvas();
final ServerCountLabel serverCountLabel = new ServerCountLabel();
ItemSupplyXmlDS supplyXmlDS = new ItemSupplyXmlDS(SC.generateID()) {
// this approach logs simulated server trips for DataSources with
// clientOnly:true
// so that no server is required. Since this example has a clientOnly
// datasource that loads data
// from a static xml, use the simulated server trips getClientOnlyResponse
// override point.
// If working with a real server that returns data dynamically based on
// start/end row, override
// transformResponse instead.
@Override
public DSResponse getClientOnlyResponse(DSRequest request) {
DSResponse response = super.getClientOnlyResponse(request);
int totalRows = response.getTotalRows();
int startRow = response.getStartRow();
int endRow = response.getEndRow();
serverCountLabel.incrementAndUpdate(totalRows, startRow, endRow);
serverCountLabel.setBackgroundColor("ffff77");
new Timer() {
public void run() {
serverCountLabel.setBackgroundColor("ffffff");
}
}.schedule(500);
return response;
}
};
// when working with a server that dynamically returns the response based on
// start row, end row,
// use can override transformResponse instead of getClientOnlyResponse
/*
* protected void transformResponse(DSResponse response, DSRequest request,
* Object data) { int totalRows = response.getTotalRows(); int startRow =
* response.getStartRow(); int endRow = response.getEndRow();
* serverCountLabel.incrementAndUpdate(totalRows, startRow, endRow);
* serverCountLabel.setBackgroundColor("ffff77"); new Timer() { public void
* run() { serverCountLabel.setBackgroundColor("ffffff"); } }.schedule(500); }
*/
final ListGrid supplyItemGrid = new ListGrid();
supplyItemGrid.setWidth(500);
supplyItemGrid.setHeight(300);
supplyItemGrid.setAlternateRecordStyles(true);
supplyItemGrid.setDataSource(supplyXmlDS);
supplyItemGrid.setAutoFetchData(true);
supplyItemGrid.setDataPageSize(20);
ListGridField skuField = new ListGridField("SKU", 100);
ListGridField nameField = new ListGridField("itemName", 150);
ListGridField descriptionField = new ListGridField("description", 250);
ListGridField categoryField = new ListGridField("category", 100);
supplyItemGrid.setFields(skuField, nameField, descriptionField, categoryField);
DynamicForm sortForm = new DynamicForm();
sortForm.setWidth(300);
sortForm.setTop(310);
final CheckboxItem restrictItem = new CheckboxItem();
restrictItem.setName("restrict");
restrictItem.setTitle("Limit to Dictionaries");
restrictItem.addChangedHandler(new ChangedHandler() {
public void onChanged(ChangedEvent event) {
Criteria criteria = new Criteria();
Object value = restrictItem.getValue();
boolean filter = value != null && (Boolean) value;
if (filter) {
criteria.addCriteria("category", "Dictionaries");
}
supplyItemGrid.fetchData(criteria);
}
});
sortForm.setFields(restrictItem);
canvas.addChild(supplyItemGrid);
canvas.addChild(sortForm);
canvas.addChild(serverCountLabel);
return canvas;
}
class ServerCountLabel extends Label {
private int count = 0;
ServerCountLabel() {
setContents("<b>Number of server trips : 0</b>");
setTop(350);
setPadding(10);
setWidth(500);
setHeight(30);
setBorder("1px solid black");
}
public void incrementAndUpdate(int totalRows, int startRow, int endRow) {
count++;
setContents("<b>Number of server trips: " + count + "</b>");
}
}
}
class SupplyCategoryXmlDS extends DataSource {
private static SupplyCategoryXmlDS instance = null;
public static SupplyCategoryXmlDS getInstance() {
if (instance == null) {
instance = new SupplyCategoryXmlDS("supplyCategoryDS");
}
return instance;
}
public SupplyCategoryXmlDS(String id) {
setID(id);
setRecordXPath("/List/supplyCategory");
DataSourceTextField itemNameField = new DataSourceTextField("categoryName", "Item", 128, true);
itemNameField.setPrimaryKey(true);
DataSourceTextField parentField = new DataSourceTextField("parentID", null);
parentField.setHidden(true);
parentField.setRequired(true);
parentField.setRootValue("root");
parentField.setForeignKey("supplyCategoryDS.categoryName");
setFields(itemNameField, parentField);
setDataURL("ds/test_data/supplyCategory.data.xml");
setClientOnly(true);
}
}
class ItemSupplyXmlDS extends DataSource {
private static ItemSupplyXmlDS instance = null;
public static ItemSupplyXmlDS getInstance() {
if (instance == null) {
instance = new ItemSupplyXmlDS("supplyItemDS");
}
return instance;
}
public ItemSupplyXmlDS(String id) {
setID(id);
setRecordXPath("/List/supplyItem");
DataSourceIntegerField pkField = new DataSourceIntegerField("itemID");
pkField.setHidden(true);
pkField.setPrimaryKey(true);
DataSourceTextField itemNameField = new DataSourceTextField("itemName", "Item Name", 128, true);
DataSourceTextField skuField = new DataSourceTextField("SKU", "SKU", 10, true);
DataSourceTextField descriptionField = new DataSourceTextField("description", "Description",
2000);
DataSourceTextField categoryField = new DataSourceTextField("category", "Category", 128, true);
categoryField.setForeignKey("supplyCategoryDS.categoryName");
DataSourceEnumField unitsField = new DataSourceEnumField("units", "Units", 5);
unitsField.setValueMap("Roll", "Ea", "Pkt", "Set", "Tube", "Pad", "Ream", "Tin", "Bag", "Ctn",
"Box");
DataSourceFloatField unitCostField = new DataSourceFloatField("unitCost", "Unit Cost", 5);
FloatRangeValidator rangeValidator = new FloatRangeValidator();
rangeValidator.setMin(0);
rangeValidator.setErrorMessage("Please enter a valid (positive) cost");
FloatPrecisionValidator precisionValidator = new FloatPrecisionValidator();
precisionValidator.setPrecision(2);
precisionValidator.setErrorMessage("The maximum allowed precision is 2");
unitCostField.setValidators(rangeValidator, precisionValidator);
DataSourceBooleanField inStockField = new DataSourceBooleanField("inStock", "In Stock");
DataSourceDateField nextShipmentField = new DataSourceDateField("nextShipment", "Next Shipment");
setFields(pkField, itemNameField, skuField, descriptionField, categoryField, unitsField,
unitCostField, inStockField, nextShipmentField);
setDataURL("ds/test_data/supplyItem.data.xml");
setClientOnly(true);
}
}
class CountryXmlDS extends DataSource {
private static CountryXmlDS instance = null;
public static CountryXmlDS getInstance() {
if (instance == null) {
instance = new CountryXmlDS("countryDS");
}
return instance;
}
public CountryXmlDS(String id) {
setID(id);
setRecordXPath("/List/country");
DataSourceIntegerField pkField = new DataSourceIntegerField("pk");
pkField.setHidden(true);
pkField.setPrimaryKey(true);
DataSourceTextField countryCodeField = new DataSourceTextField("countryCode", "Code");
countryCodeField.setRequired(true);
DataSourceTextField countryNameField = new DataSourceTextField("countryName", "Country");
countryNameField.setRequired(true);
DataSourceTextField capitalField = new DataSourceTextField("capital", "Capital");
DataSourceTextField governmentField = new DataSourceTextField("government", "Government", 500);
DataSourceBooleanField memberG8Field = new DataSourceBooleanField("member_g8", "G8");
DataSourceTextField continentField = new DataSourceTextField("continent", "Continent");
continentField.setValueMap("Europe", "Asia", "North America", "Australia/Oceania",
"South America", "Africa");
DataSourceDateField independenceField = new DataSourceDateField("independence", "Nationhood");
DataSourceFloatField areaField = new DataSourceFloatField("area", "Area (km&sup2;)");
DataSourceIntegerField populationField = new DataSourceIntegerField("population", "Population");
DataSourceFloatField gdpField = new DataSourceFloatField("gdp", "GDP ($M)");
DataSourceLinkField articleField = new DataSourceLinkField("article", "Info");
setFields(pkField, countryCodeField, countryNameField, capitalField, governmentField,
memberG8Field, continentField, independenceField, areaField, populationField, gdpField,
articleField);
setDataURL("ds/test_data/country.data.xml");
setClientOnly(true);
}
}
SmartGWT.zip( 9,880 k)
