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    1   /*
    2    * $Id: ComboBox.java 497654 2007-01-19 00:21:57Z rgielen $
    3    *
    4    * Licensed to the Apache Software Foundation (ASF) under one
    5    * or more contributor license agreements.  See the NOTICE file
    6    * distributed with this work for additional information
    7    * regarding copyright ownership.  The ASF licenses this file
    8    * to you under the Apache License, Version 2.0 (the
    9    * "License"); you may not use this file except in compliance
    10   * with the License.  You may obtain a copy of the License at
    11   *
    12   *  http://www.apache.org/licenses/LICENSE-2.0
    13   *
    14   * Unless required by applicable law or agreed to in writing,
    15   * software distributed under the License is distributed on an
    16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    17   * KIND, either express or implied.  See the License for the
    18   * specific language governing permissions and limitations
    19   * under the License.
    20   */
    21  package org.apache.struts2.components;
    22
    23  import java.util.Collection;
    24  import java.util.Iterator;
    25  import java.util.Map;
    26
    27  import javax.servlet.http.HttpServletRequest;
    28  import javax.servlet.http.HttpServletResponse;
    29
    30  import org.apache.struts2.views.annotations.StrutsTag;
    31  import org.apache.struts2.views.annotations.StrutsTagAttribute;
    32  import org.apache.struts2.util.MakeIterator;
    33
    34  import com.opensymphony.xwork2.util.ValueStack;
    35
    36  /***
    37   * <!-- START SNIPPET: javadoc -->
    38   * The combo box is basically an HTML INPUT of type text and HTML SELECT grouped together to give you a combo box
    39   * functionality. You can place text in the INPUT control by using the SELECT control or type it in directly in
    40   * the text field.<p/>
    41   *
    42   * In this example, the SELECT will be populated from id=year attribute. Counter is itself an Iterator. It will
    43   * span from first to last. The population is done via javascript, and requires that this tag be surrounded by a
    44   * &lt;form&gt;.<p/>
    45   *
    46   * Note that unlike the &lt;s:select/&gt; tag, there is no ability to define the individual &lt;option&gt; tags' id attribute
    47   * or content separately. Each of these is simply populated from the toString() method of the list item. Presumably
    48   * this is because the select box isn't intended to actually submit useful data, but to assist the user in filling
    49   * out the text field.<p/>
    50   * <!-- END SNIPPET: javadoc -->
    51   *
    52   * <p/> <b>Examples</b>
    53   *
    54   * <pre>
    55   * <!-- START SNIPPET: example -->
    56   * JSP:
    57   * &lt;-- Example One --&gt;
    58   * &lt;s:bean name="struts.util.Counter" id="year"&gt;
    59   *   &lt;s:param name="first" value="text('firstBirthYear')"/&gt;
    60   *   &lt;s:param name="last" value="2000"/&gt;
    61   *
    62   *   &lt;s:combobox label="Birth year" size="6" maxlength="4" name="birthYear" list="#year"/&gt;
    63   * &lt;/s:bean&gt;
    64   *
    65   * &lt;-- Example Two --&gt;
    66   * <s:combobox
    67   *     label="My Favourite Fruit"
    68   *     name="myFavouriteFruit"
    69   *     list="{'apple','banana','grape','pear'}"
    70   *     headerKey="-1"
    71   *     headerValue="--- Please Select ---"
    72   *     emptyOption="true"
    73   *     value="banana" />
    74   *
    75   * &lt;-- Example Two --&gt;
    76   * <s:combobox
    77   *    label="My Favourite Color"
    78   *    name="myFavouriteColor"
    79   *    list="#{'red':'red','green':'green','blue':'blue'}"
    80   *    headerKey="-1"
    81   *    headerValue="--- Please Select ---"
    82   *    emptyOption="true"
    83   *    value="green" />
    84   *
    85   * Velocity:
    86   * #tag( ComboBox "label=Birth year" "size=6" "maxlength=4" "name=birthYear" "list=#year" )
    87   * <!-- END SNIPPET: example -->
    88   * </pre>
    89   *
    90   */
    91  @StrutsTag(name="combobox", tldTagClass="org.apache.struts2.views.jsp.ui.ComboBoxTag", description="Widget that fills a text box from a select")
    92  public class ComboBox extends TextField {
    93      final public static String TEMPLATE = "combobox";
    94
    95      protected String list;
    96      protected String listKey;
    97      protected String listValue;
    98      protected String headerKey;
    99      protected String headerValue;
    100     protected String emptyOption;
    101
    102
    103     public ComboBox(ValueStack stack, HttpServletRequest request, HttpServletResponse response) {
    104         super(stack, request, response);
    105     }
    106
    107     protected String getDefaultTemplate() {
    108         return TEMPLATE;
    109     }
    110
    111     public void evaluateExtraParams() {
    112         super.evaluateExtraParams();
    113
    114         Object value = findListValue();
    115
    116         if (headerKey != null) {
    117             addParameter("headerKey", findString(headerKey));
    118         }
    119         if (headerValue != null) {
    120             addParameter("headerValue", findString(headerValue));
    121         }
    122         if (emptyOption != null) {
    123             addParameter("emptyOption", findValue(emptyOption, Boolean.class));
    124         }
    125
    126         if (value != null) {
    127             if (value instanceof Collection) {
    128                 Collection tmp = (Collection) value;
    129                 addParameter("list", tmp);
    130                 if (listKey != null) {
    131                     addParameter("listKey", listKey);
    132                 }
    133                 if (listValue != null) {
    134                     addParameter("listValue", listValue);
    135                 }
    136             } else if (value instanceof Map) {
    137                 Map tmp = (Map) value;
    138                 addParameter("list", MakeIterator.convert(tmp));
    139                 addParameter("listKey", "key");
    140                 addParameter("listValue", "value");
    141             } else if (value.getClass().isArray()) {
    142                 Iterator i = MakeIterator.convert(value);
    143                 addParameter("list", i);
    144                 if (listKey != null) {
    145                     addParameter("listKey", listKey);
    146                 }
    147                 if (listValue != null) {
    148                     addParameter("listValue", listValue);
    149                 }
    150             } else {
    151                 Iterator i = MakeIterator.convert(value);
    152                 addParameter("list", i);
    153                 if (listKey != null) {
    154                     addParameter("listKey", listKey);
    155                 }
    156                 if (listValue != null) {
    157                     addParameter("listValue", listValue);
    158                 }
    159             }
    160         }
    161     }
    162
    163     protected Object findListValue() {
    164         return findValue(list, "list",
    165                 "You must specify a collection/array/map/enumeration/iterator. " +
    166                 "Example: people or people.{name}");
    167     }
    168
    169     @StrutsTagAttribute(description="Iteratable source to populate from. " +
    170                 "If this is missing, the select widget is simply not displayed.", required=true)
    171     public void setList(String list) {
    172         this.list = list;
    173     }
    174
    175     @StrutsTagAttribute(description="Decide if an empty option is to be inserted. Default false.")
    176     public void setEmptyOption(String emptyOption) {
    177         this.emptyOption = emptyOption;
    178     }
    179
    180     @StrutsTagAttribute(description="Set the header key for the header option.")
    181     public void setHeaderKey(String headerKey) {
    182         this.headerKey = headerKey;
    183     }
    184
    185     @StrutsTagAttribute(description="Set the header value for the header option.")
    186     public void setHeaderValue(String headerValue) {
    187         this.headerValue = headerValue;
    188     }
    189
    190     @StrutsTagAttribute(description="Set the key used to retrive the option key.")
    191     public void setListKey(String listKey) {
    192         this.listKey = listKey;
    193     }
    194
    195     @StrutsTagAttribute(description="Set the value used to retrive the option value.")
    196     public void setListValue(String listValue) {
    197         this.listValue = listValue;
    198     }
    199
    200
    201 }