ConfigurePager


1   /*
2    * Copyright 2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
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9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   *
16   * $Header:$
17   */
18  package org.apache.beehive.netui.tags.databinding.datagrid;
19  
20  import javax.servlet.jsp.JspException  ;
21  import javax.servlet.http.HttpServletRequest  ;
22  
23  import org.apache.beehive.netui.databinding.datagrid.api.exceptions.DataGridExtensionException;
24  import org.apache.beehive.netui.databinding.datagrid.api.rendering.DataGridTagModel;
25  import org.apache.beehive.netui.databinding.datagrid.api.rendering.PagerRenderer;
26  import org.apache.beehive.netui.databinding.datagrid.runtime.rendering.pager.FirstPreviousNextLastPagerRenderer;
27  import org.apache.beehive.netui.databinding.datagrid.runtime.rendering.pager.PreviousNextPagerRenderer;
28  import org.apache.beehive.netui.databinding.datagrid.runtime.util.JspUtil;
29  import org.apache.beehive.netui.databinding.datagrid.runtime.util.ExtensionUtil;
30  import org.apache.beehive.netui.databinding.datagrid.api.pager.PagerModel;
31  import org.apache.beehive.netui.tags.AbstractSimpleTag;
32  import org.apache.beehive.netui.util.logging.Logger;
33  import org.apache.beehive.netui.util.Bundle;
34  
35  /**
36   * <p>
37   * The configurePager tag is used to parameterize the data used to render a data grid's pager.  This
38   * tag should be used inside of a &lt;netui-data:dataGrid&gt; tag.  The tag supports adding a custom
39   * {@link PagerRenderer} via the {@link #setPagerRendererClass(String)}, overriding the default page
40   * size for a data grid via the {@link #setDefaultPageSize(Integer)} attribute, and setting
41   * the current data grid's page size via the {@link #setPageSize(int)} attribute.  This tag produces
42   * no output and does not evaluate its body.
43   * </p>
44   * @jsptagref.tagdescription
45   * <p>
46   * The configurePager tag is used to parameterize the data used to render a data grid's pager.  This
47   * tag should be used inside of a &lt;netui-data:dataGrid&gt; tag.  The tag supports adding a custom
48   * {@link PagerRenderer} via the {@link #setPagerRendererClass(String)}, overriding the default page
49   * size for a data grid via the {@link #setDefaultPageSize(Integer)} attribute, and setting
50   * the current data grid's page size via the {@link #setPageSize(int)} attribute.  This tag produces
51   * no output and does not evaluate its body.
52   * </p>
53   * @netui:tag name="configurePager" body-content="empty"
54   * description="Pager tag for the configuring and rendering the pager rendered in the NetUI data grid"
55   */
56  public class ConfigurePager
57          extends AbstractSimpleTag {
58  
59      private static final Logger LOGGER = Logger.getInstance(ConfigurePager.class);
60      private static final String   PAGER_FORMAT_FIRST_LAST_PREV_NEXT = "firstPrevNextLast";
61      private static final String   PAGER_FORMAT_PREV_NEXT = "prevNext";
62  
63      private Boolean   _disableDefaultPager = null;
64      private Integer   _pageSize = null;
65      private Integer   _defaultPageSize = null;
66      private String   _pagerFormat = null;
67      private String   _pageHref = null;
68      private String   _pageAction = null;
69      private String   _pagerRendererClass = null;
70  
71      /**
72       * The name of this tag; this value is used for error reporting.
73       * @return the String name of this tag
74       */
75      public String   getTagName() {
76          return "ConfigurePager";
77      }
78  
79      /**
80       * Set the page size for the current data grid.  This value is the maximum number of data rows
81       * that will be rendered by a data grid.  When this value is set, it overides the
82       * {@link #setDefaultPageSize(Integer)} attribute.  If this value is not set, the
83       * {@link #setDefaultPageSize(Integer)} is used to determine the maximum size of a data grid's
84       * page.  Use this value when a data grid allows a user to vary the number of rows in a grid.
85       * @jsptagref.attributedescription
86       * Set the page size for the current data grid.  This value is the maximum number of data rows
87       * that will be rendered by a data grid.  When this value is set, it overides the
88       * {@link #setDefaultPageSize(Integer)} attribute.  If this value is not set, the
89       * {@link #setDefaultPageSize(Integer)} is used to determine the maximum size of a data grid's
90       * page.  Use this value when a data grid allows a user to vary the number of rows in a grid.
91       * @jsptagref.attributesyntaxvalue <i>int_pageSize</i>
92       * @netui:attribute required="false" rtexprvalue="true"
93       *                  description="Set the maximum number of rows to render for a data grid."
94       */
95      public void setPageSize(int pageSize) {
96          _pageSize = new Integer  (pageSize);
97      }
98  
99      /**
100      * Set the appearance of the pager rendered by the data grid.  This attribute allows the page author to
101      * choose from a set of pre-defined pager renderers which can be used to render paging UI
102      * in a data grid.  The values include:
103      * <b>prevNext</b> which renders a pager as:<br/>
104      * <pre>
105      *   Page # of # Previous Next
106      * </pre>
107      * where Previous and Next are anchors that can navigate to the previous and next pages.  When
108      * there is no previous or next page, Previous or Next are displayed as literal text.
109      * <br/>
110      * <br/>
111      * <b>firstPrevNextLast</b> which renders a pager as:<br/>
112      * <pre>
113      *   Page # of # First Previous Next Last
114      * </pre>
115      * where First, Previous, Next, and Last are anchors that can navigate to the first, previous, next, and last
116      * pages respectively.  When the anchors would reference invalid pages, First, Previous, Nest, and Last
117      * are displayed as literal text.
118      * @jsptagref.attributedescription
119      * Set the style of the pager rendered by the data grid.  This attribute allows the page author to
120      * choose from a set of pre-defined pager renderers which can be used to render paging UI
121      * in a data grid.  The values include:
122      * <b>prevNext</b> which renders a pager as:<br/>
123      * <pre>
124      *   Page # of # Previous Next
125      * </pre>
126      * where Previous and Next are anchors that can navigate to the previous and next pages.  When
127      * there is no previous or next page, Previous or Next are displayed as literal text.
128      * <br/>
129      * <br/>
130      * <b>firstPrevNextLast</b> which renders a pager as:<br/>
131      * <pre>
132      *   Page # of # First Previous Next Last
133      * </pre>
134      * where First, Previous, Next, and Last are anchors that can navigate to the first, previous, next, and last
135      * pages respectively.  When the anchors would reference invalid pages, First, Previous, Nest, and Last
136      * are displayed as literal text.
137      * @jsptagref.attributesyntaxvalue <i>String_pagerStyle</i>
138      * @netui:attribute required="false" rtexprvalue="true"
139      *                  description="Set the appearance of the pager rendered by the data grid.
140      */
141     public void setPagerFormat(String   pagerFormat) {
142         _pagerFormat = pagerFormat;
143     }
144 
145     /**
146      * Set the HREF used to perform paging.  When a pager renders anchors for navigating the data set
147      * inside of the data grid, this HREF when set is used as the request URI to perform the paging.
148      * Only one of this and the {@link #setPageAction(String)} may be set.
149      * @jsptagref.attributedescription
150      * Set the HREF used to perform paging.  When a pager renders anchors for navigating the data set
151      * inside of the data grid, this HREF when set is used as the request URI to perform the paging.
152      * Only one of this and the {@link #setPageAction(String)} may be set.
153      * @jsptagref.attributesyntaxvalue <i>String_pageUri</i>
154      * @netui:attribute required="false" rtexprvalue="true" description="The HREF used when building HTML
155      * anchors that perform paging."
156      */
157     public void setPageHref(String   pageHref) {
158         _pageHref = pageHref;
159     }
160 
161     /**
162      * Set the action used to perform paging.  When a pager renders anchors for navigating the
163      * data set in a data grid, this action is used as the request URI to perform the paging.
164      * Only one of this and the {@link #setPageHref(String)} may be set.
165      * @jsptagref.attributedescription
166      * Set the action used to perform paging.  When a pager renders anchors for navigating the
167      * data set in a data grid, this action is used as the request URI to perform the paging.
168      * Only one of this and the {@link #setPageHref(String)} may be set.
169      * @jsptagref.attributesyntaxvalue <i>String_pageAction</i>
170      * @netui:attribute required="false" rtexprvalue="true"
171      *                  description="The action used when building HTML anchors that perrform paging.
172      */
173     public void setPageAction(String   pageAction) {
174         _pageAction = pageAction;
175     }
176 
177     /**
178      * Sets the value of an attribute that enables or disables rendering the data grid's default pager.
179      * When this value is set to <code>false</code>, the data grid will not render its pager and rendering
180      * is left to the page author.  When rendering is disabled, a pager can be rendered using the
181      * {@link RenderPager} tag or manually in a page.
182      * @jsptagref.attributedescription
183      * Sets the value of an attribute that enables or disables rendering the data grid's default pager.
184      * When this value is set to <code>false</code>, the data grid will not render its pager and rendering
185      * is left to the page author.  When rendering is disabled, a pager can be rendered using the
186      * {@link RenderPager} tag or manually in a page.
187      * @jsptagref.attributesyntaxvalue <i>boolean</i>
188      * @netui:attribute required="false" rtexprvalue="true"
189      *                  description="Boolean that enables / disables a data grid rendering the pager in its default location"
190      */
191     public void setDisableDefaultPager(boolean disableDefaultPager) {
192         _disableDefaultPager = Boolean.valueOf(disableDefaultPager);
193     }
194 
195     /**
196      * Set a Java class name to create a {@link PagerRenderer} used to render a data grid's pager.  The
197      * class referenced by this name must extend the {@link PagerRenderer} base class.
198      * @jsptagref.attributedescription
199      * Set a Java class name to create a {@link PagerRenderer} used to render a data grid's pager.  The
200      * class referenced by this name must extend the {@link PagerRenderer} base class.
201      * @jsptagref.attributesyntaxvalue <i>string</i>
202      * @netui:attribute required="false" rtexprvalue="true"
203      *                  description="The data grid pager's custom pager render classname"
204      */
205     public void setPagerRendererClass(String   pagerRendererClass) {
206         _pagerRendererClass = pagerRendererClass;
207     }
208 
209     /**
210      * Set the default page size for the data grid.  The grid has a default page size that is used
211      * when no other page size is specified; this value is {@link PagerModel#DEFAULT_PAGE_SIZE}.
212      * This value overrides that default so that the normal rendering of such a data grid is
213      * change in the absence of an override provided by the {@link #setPageSize(int)} attribute.
214      *
215      * @jsptagref.attributedescription
216      * Set the default page size for the data grid.  The grid has a default page size that is used
217      * when no other page size is specified; this value is {@link PagerModel#DEFAULT_PAGE_SIZE}.
218      * This value overrides that default so that the normal rendering of such a data grid is
219      * change in the absence of an override provided by the {@link #setPageSize(int)} attribute.
220      * @jsptagref.attributesyntaxvalue <i>string</i>
221      * @netui:attribute required="false" rtexprvalue="true" description="The data grid pager's default page size"
222      */
223     public void setDefaultPageSize(Integer   defaultPageSize) {
224         _defaultPageSize = defaultPageSize;
225     }
226 
227     /**
228      * Execute the ConfigurePager tag.  When the ConfigurePager tag runs, it applies its tag attributes
229      * onto a {@link DataGridTagModel} state object which is used when the data grid renders its pager.
230      * @throws JspException when errors occur when processing this tag's attribute values
231      */
232     public void doTag()
233         throws JspException   {
234 
235         DataGridTagModel dgm = DataGridUtil.getDataGridTagModel(getJspContext());
236         if(dgm == null)
237             throw new JspException  (Bundle.getErrorString("DataGridTags_MissingDataGridModel"));
238 
239         PagerModel pm = dgm.getState().getPagerModel();
240         assert pm != null;
241 
242         if(_disableDefaultPager != null)
243             dgm.setDisableDefaultPagerRendering(_disableDefaultPager.booleanValue());
244 
245         if(_pageSize != null)
246             pm.setPageSize(_pageSize.intValue());
247 
248         if(_defaultPageSize != null)
249             pm.setDefaultPageSize(_defaultPageSize.intValue());
250 
251         PagerRenderer pagerRenderer = null;
252         if(_pagerRendererClass != null) {
253             try {
254                 pagerRenderer = (PagerRenderer)ExtensionUtil.instantiateClass(_pagerRendererClass, PagerRenderer.class);
255                 assert pagerRenderer != null : "Expected a non-null pager renderer of type \"" + _pagerRendererClass + "\"";
256             }
257             catch(DataGridExtensionException e) {
258                 String   msg = Bundle.getErrorString("ConfigurePager_CantCreateCustomPagerRenderer", new Object  []{e});
259                 throw new JspException  (msg, e);
260             }
261         }
262         else if(_pagerFormat != null) {
263             if(_pagerFormat.equals(PAGER_FORMAT_FIRST_LAST_PREV_NEXT))
264                 pagerRenderer = new FirstPreviousNextLastPagerRenderer();
265             else if(_pagerFormat.equals(PAGER_FORMAT_PREV_NEXT))
266                 pagerRenderer = new PreviousNextPagerRenderer();
267             else
268                 throw new JspException  (Bundle.getErrorString("ConfigurePager_UnsupportedPagerFormat", new Object  []{_pagerFormat}));
269         }
270 
271         if(pagerRenderer != null)
272             dgm.setPagerRenderer(pagerRenderer);
273 
274         if(_pageHref != null && _pageAction != null)
275             throw new JspException  (Bundle.getErrorString("ConfigurePager_CantSetHrefAndAction"));
276 
277         if(_pageHref == null && _pageAction == null) {
278             LOGGER.info("The configurePager tag has no page action or HREF specified; using the current request URI instead.");
279             _pageHref = ((HttpServletRequest  )JspUtil.getRequest(getJspContext())).getRequestURI();
280         }
281 
282         if(_pageHref != null)
283             pm.setPageHref(_pageHref);
284 
285         if(_pageAction != null)
286             pm.setPageAction(_pageAction);
287     }
288 }
289 
290
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