Grails によるリッチ・インターネット・アプリケーション: 第 2 回 Grails と Google Web Toolkit

class SearchService {

    boolean transactional = false

    def list() {
        Story.list()
    }

    def listCategory(catName){
        Story.findAllWhere(category:catName)
    }
    
    def searchTag(tag){
        Story.findAllByTagsIlike("%"+tag+"%")
    }
}

import grails.converters.*

class ApiController {
    // injected services
    def searchService
    def storyService

    def search = {
        def results= null
        def tagResults = null
        if (params.tag){
            tagResults = searchService.searchTag(params.tag)
        }
        def catResults = null
        if (params.category){
            catResults = searchService.listCategory(params.category)
        }
        if (params.tag && params.category){
            def tagMap = [:]
            tagResults.each{ story ->
                tagMap[story.id] = story
            }
            results = catResults.findAll { tagMap[it.id] != null} 
        } else {
            if (params.category){
                results = catResults
            } else {
                results = tagResults
            }
         }
        render results as JSON
    }
}

[{"id":1,"class":"Story","category":"technology","description":"How to get 
a ternary operator in Scala","link":"http://blog.tmorris.net/does-scala-have-
javas-ternary-operator/","tags":"programming scala","title":"Does Scala have 
Java's ternary operator?","votesAgainst":0,"votesFor":0},{"id":3,"class":"Story",
"category":"technology","description":"New animations available in the Flex 4 'Gumbo'
 release.","link":"http://graphics-geek.blogspot.com/2008/10/flex-specificanimations
-posted.html","tags":"flash flex","title":"Flex Specific Animations Posted",
"votesAgainst":0,"votesFor":0}]

public class DiggApp implements EntryPoint {

    private static final String[][] CATEGORIES = {
        { "Technology", "technology" }, { "World & Business", "business" },
        { "Science", "science" }, { "Gaming", "games" },
        { "Lifestyle", "lifestyle" }, { "Entertainment", "entertainment" },
        { "Sports", "sports" }, { "Offbeat", "miscellaneous" } };

    private final HorizontalPanel searchPanel = createSearchForm();
    private final VerticalPanel resultsPanel = new VerticalPanel();

    public void onModuleLoad() {
        RootPanel.get().add(searchPanel);
        RootPanel.get().add(resultsPanel);
    }
    private HorizontalPanel createSearchForm() {
        HorizontalPanel panel = new HorizontalPanel();
        panel.setTitle("Search for Stories");
        Label tagLabel = new Label("Tag:");
        final TextBox tagBox = new TextBox();
        panel.add(tagLabel);
        panel.add(tagBox);
        Label catLabel = new Label("Category:");
        final ListBox catBox = new ListBox();
        catBox.addItem("");
        for (String[] category : CATEGORIES){
            catBox.addItem(category[0],category[1]);
        }
        panel.add(catLabel);
        panel.add(catBox);
        Button searchBtn = new Button("Search");
        searchBtn.addClickListener(new ClickListener(){
            public void onClick(Widget sender) {
                search(tagBox.getText(), catBox.getValue(catBox.getSelectedIndex()));
            }
        });
        panel.add(searchBtn);
        return panel;
    }
}

private final void search(String tag, String category){
    resultsPanel.clear();
    Story.search(tag, category, new RequestCallback(){
        public void onError(Request request, Throwable exception) {
            Label label = new Label("Sorry there was an error");
            resultsPanel.add(label);
        }
        public void onResponseReceived(Request request, Response response) {
            List<Story> stories = Story.fromJson(response.getText());
            SearchTable grid = new SearchTable(stories);
            resultsPanel.add(grid);
        }
    });
}    

public class Story {

    private static final String BASE_URL = "/digg/api/search?";
    
    private int id;
    private String link;
    private String title;
    private String description;
    private String tags;
    private String category;
    private int votesFor;
    private int votesAgainst;

    public Story(JSONObject obj){
        id = (int) obj.get("id").isNumber().doubleValue();
        link = obj.get("link").isString().stringValue();
        title = obj.get("title").isString().stringValue();
        description = obj.get("description").isString().stringValue();
        tags = obj.get("tags").isString().stringValue();
        category = obj.get("category").isString().stringValue();
        votesFor = (int) obj.get("votesFor").isNumber().doubleValue();
        votesAgainst = (int) obj.get("votesAgainst").isNumber().doubleValue();
    }
    
    public static void search(final String tag, final String category, final 
RequestCallback callback){
        String url = buildRequest(tag, category);
        RequestBuilder builder = 
            new RequestBuilder(RequestBuilder.GET, url);
        try {
            builder.sendRequest(null, new RequestCallback(){
                public void onError(Request request, Throwable exception) {
                    callback.onError(request, exception);
                }
                public void onResponseReceived(Request request, Response response) {
                    callback.onResponseReceived(request, response);
                }                
            });
        } catch (RequestException e) {
            callback.onError(null, e);
        }
    }
}

public static List<Story> fromJson(String jsonText){
    JSONValue val = JSONParser.parse(jsonText);
    JSONArray array = val.isArray();
    List<Story> stories = new ArrayList<Story>(array.size());
    for (int i=0;i<array.size();i++){
        Story story = new Story(array.get(i).isObject());
        stories.add(story);
    }
    return stories;
}

public class SearchTable extends FlexTable {
    private List<Story> stories;
    public SearchTable(List<Story> stories) {
        super();
        this.stories = stories;
        this.buildTable();
    }
    private void buildTable(){
        this.setBorderWidth(2);
        this.setText(0, 0, "story");
        this.setText(0, 1, "category");
        this.setText(0, 2, "description");
        if (stories.size() == 0){
            showMessage("Sorry there were no results");
        } else {
            for (int i=0;i<stories.size();i++){
                Story story = stories.get(i);
                setWidget(i+1, 0, story.getTitleLink());
                setText(i+1, 1, story.getCategory());
                setText(i+1, 2, story.getDescription());
            }
        }
    }
    private void showMessage(String msg){
        setText(1,0, msg);
        getFlexCellFormatter().setColSpan(1, 0, 3);
    }    
}

<module>

      <!-- Inherit the core Web Toolkit stuff.                        -->
      <inherits name='com.google.gwt.user.User'/>
    
      <!-- Inherit the default GWT style sheet.  You can change       -->
      <!-- the theme of your GWT application by uncommenting          -->
      <!-- any one of the following lines.                            -->
      <inherits name='com.google.gwt.user.theme.standard.Standard'/>
      <!-- <inherits name='com.google.gwt.user.theme.chrome.Chrome'/> -->
      <!-- <inherits name='com.google.gwt.user.theme.dark.Dark'/>     -->

      <!-- Other module inherits                                      -->
      <inherits name="com.google.gwt.http.HTTP" />
      <inherits name="com.google.gwt.json.JSON" />

      <!-- Specify the app entry point class.                         -->
      <entry-point class='org.developerworks.digg.client.DiggApp'/>
    
      <!-- Specify the application specific style sheet.              -->
      <stylesheet src='DiggApp.css' />
</module>

$ ./DiggApp-compile
Compiling module org.developerworks.digg.DiggApp
2008-11-08 19:56:14.962 java[1300:c1b] 
      [Java CocoaComponent compatibility mode]: Enabled
2008-11-08 19:56:14.963 java[1300:c1b] [Java CocoaComponent compatibility mode]: 
      Setting timeout for SWT to 0.100000
Compilation succeeded
Linking compilation into ./www/org.developerworks.digg.DiggApp

#!/bin/sh
APPDIR=`dirname $0`;
java -XstartOnFirstThread -Xmx256M -cp "$APPDIR/src:$APPDIR/bin:
/Users/michael/lib/gwt-mac-1.5.3/gwt-user.jar:
/Users/michael/lib/gwt-mac-1.5.3/gwt-dev-mac.jar:./lib/gxt.jar" 
com.google.gwt.dev.GWTCompiler -out "$APPDIR/www" "$@" 
org.developerworks.digg.DiggApp;

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">  

<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=UTF-8">
    <!--                                           -->
    <!-- Any title is fine                         -->
    <!--                                           -->
    <title>DiggApp</title>
    
    <!--                                           -->
    <!-- This script loads your compiled module.   -->
    <!-- If you add any GWT meta tags, they must   -->
    <!-- be added before this line.                -->
    <!--                                           -->
    <script type="text/javascript" language="javascript" 
        src="org.developerworks.digg.DiggApp.nocache.js"></script>
    <link rel="stylesheet" type="text/css" href="css/ext-all.css" />
  </head>

  <!--                                           -->
  <!-- The body can have arbitrary html, or      -->
  <!-- you can leave the body empty if you want  -->
  <!-- to create a completely dynamic UI.        -->
  <!--                                           -->
  <body>

    <!-- OPTIONAL: include this if you want history support -->
    <iframe src="javascript:''" id="__gwt_historyFrame" tabIndex='-1' 
        style="position:absolute;width:0;height:0;border:0"></iframe>

  </body>
</html>

<module>

      <!-- Inherit the core Web Toolkit stuff.                        -->
      <inherits name='com.google.gwt.user.User'/>
    
      <!-- Inherit the default GWT style sheet.  You can change       -->
      <!-- the theme of your GWT application by uncommenting          -->
      <!-- any one of the following lines.                            -->
      <inherits name='com.google.gwt.user.theme.standard.Standard'/>
      <!-- <inherits name='com.google.gwt.user.theme.chrome.Chrome'/> -->
      <!-- <inherits name='com.google.gwt.user.theme.dark.Dark'/>     -->

      <!-- Other module inherits                                      -->
      <inherits name="com.google.gwt.http.HTTP" />
      <inherits name="com.google.gwt.json.JSON" />

 <inherits name='com.extjs.gxt.ui.GXT'/> 

      <!-- Specify the app entry point class.                         -->
      <entry-point class='org.developerworks.digg.client.DiggApp'/>
    
      <!-- Specify the application specific style sheet.              -->
      <stylesheet src='DiggApp.css' />
</module>

public class StoryGrid extends LayoutContainer {

    public StoryGrid(List<Story> stories){
        this.setLayout(new FlowLayout(10));
        this.setSize(750, 300);
        ListStore<BaseModelData> store = this.buildDataModel(stories);
        Grid<BaseModelData> grid = 
            new Grid<BaseModelData>(store, createColumnModel());
        grid.setBorders(true);
        add(grid);
    }
    
    private ColumnModel createColumnModel(){
        List<ColumnConfig> configs = new ArrayList<ColumnConfig>();
        ColumnConfig column = new ColumnConfig();
        column.setId("titleLink");
        column.setHeader("Story");
        column.setWidth(200);
        configs.add(column);
        column = new ColumnConfig();
        column.setId("category");
        column.setHeader("Category");
        column.setWidth(100);
        configs.add(column);
        column = new ColumnConfig();
        column.setId("description");
        column.setHeader("Description");
        column.setWidth(400);
        configs.add(column);
        return new ColumnModel(configs);
    }
    
    private ListStore<BaseModelData> buildDataModel(List<Story> stories){
        ListStore<BaseModelData> data = new ListStore<BaseModelData>();
        for (Story story : stories){
            BaseModelData model = new BaseModelData(story.properties());
            data.add(model);
        }
        return data;
    }
}

public class Story {    
    public Map<String,Object> properties(){
        Map<String,Object> props = new HashMap<String,Object>();
        props.put("id",id);
        props.put("link", link);
        props.put("title", title);
        props.put("description",description);
        props.put("tags",tags);
        props.put("category",category);
        props.put("votesFor",votesFor);
        props.put("votesAgainst",votesAgainst);
        props.put("titleLink", getTitleLink().getHTML());
        return props;
    }
}