Display a List of Search Results¶

Class diagram¶

The application programmer can implement paging without implementing the details since the classes provided by the framework and the tag files provided by the sample perform the processing required for paging.

Main attributes of the listSearchResult tag¶

The main attributes of the listSearchResult tag are shown below. For more information on all the attributes, see listSearchResult tag.

If the search result specified by the resultSetName attribute does not exist in the request scope, the listSearchResult tag will not output anything. This corresponds to the case where the initial display of the search screen does not output anything.

Search result list¶

The number of search results is displayed when true (default is true) is specified in the useResultCount attribute and the search results exist in the request scope. By default, the number of search results is output in the following format.

Search results <%-- resultCount property of pagination --%>Record

To change the default format, specify the JSP fragment in the resultCountFragment attribute. An example of specifying the resultCountFragment attribute is shown below.

<app:listSearchResult resultSetName="searchResult" useResultCount="true">

   <%-- Specify the JSP fragment in the resultCountFragment attribute. --%>
   <jsp:attribute name="resultCountFragment">
     [Search results <n:write name="searchResult.pagination.resultCount" />page]
   </jsp:attribute>

   <%-- Other attributes are omitted. --%>

</app:listSearchResult>

The format for the number of search results after the specification mentioned above is as follows.

[Search results <%-- resultCount property of pagination --%> page]

Paging¶

Paging is displayed when the usePaging attribute is specified as true (the default is true).

When using the paging function, implement so that the form specified by searchFormName receives the page number with the name pageNumber. Examples are shown below.

public class ProjectSearchForm {

  @Required
  @Domain("pageNumber")
  private String pageNumber;

  public String getPageNumber(){
    return this.pageNumber;
  }

  public String getPageNumber(){
    return this.pageNumber;
  }

  public void setPageNumber(String pageNumber){
    this.pageNumber = pageNumber;
  }

  // Omit other attributes.
}

The paging screen elements are shown below. Paging consists of the current page number and the submit elements for moving the page.

The entire paging is displayed when the number of search results is 1 or more. Assuming that the entire paging is displayed, the paging screen elements are as shown below.

The typical attributes that can be specified by the paging screen elements are as follows. For more information on all the attributes, see listSearchResult tag.

• Whether or not each screen element can be used
• Label for each screen element (such as first, previous, next, last)
• Current page number that is changed by the JSP fragment
• Page numbers that cannot be changed because they use the page number for the label

Search conditions when paging

Search conditions for paging can be realized by constructing a URI with search conditions set as parameters and passing it to the searchUri attribute. An example of specifying a project name as a search condition is shown below.

<%@ taglib prefix="c" uri="jakarta.tags.core" %>
<%@ taglib prefix="app" tagdir="/WEB-INF/tags/listSearchResult" %>

<%-- Register the URI that has the search condition used to display the current search result as a parameter in the page scope as a variable.
     This variable is used as URI for paging of <app:listSearchResult> tag. --%>
<c:url value="/action/project/list" var="uri" context="/">
   <%-- Set the project name obtained from the search form. --%>
   <c:param name="searchForm.projectName" value="${searchForm.projectName}"/>
</c:url>

<%-- Pass it to the searchUri attribute. --%>
<app:listSearchResult resultSetName="searchResult" searchUri="${uri}"

<%-- Omit other attributes. --%>

What to do when search results are reduced when using paging

This section describes what to do when the search results are reduced due to other user operations while switching the search result page with each paging submit element.

This framework performs a search based on the specified page number and displays each paging screen element. The following is an example of the paging operation when the number of search results is reduced.

As a prerequisite, the number of acquired search results (number displayed per page) is 20 results.

First, assume that a search is performed and the search results are 44 results. Below is the paging display after the third page is selected.

Next, a description of the paging display and the display contents when “Previous” is selected with the number of search results reduced to 10 will be described. Each paging screen element is displayed as a search result for the second page.

Since the current page number and the submit element correspond to each other, it is possible to move to the search results page by selecting the submit element without it becoming inoperable. (Of course, if you perform a search again from the search form, the search results will be from the first page.)

The paging display after selecting “Previous” is shown next. The correspondence between the current page number and the total number of pages returns to normal.

Search result¶

The screen elements of the search result are shown below. The search result consists of a header row that displays column headings, and a body row that displays row data.

The search results are always displayed when they are in the request scope. When the search result is 0, only the header row is displayed.

The header row and body row are specified in the headerRowFragment attribute and bodyRowFragment attributes in the JSP fragment. The JSP fragment in the body row is called and evaluated in the search result loop (c:forEach tag of JSTL). Hence, the following attributes are provided to access the row data (var attribute of the c:forEach tag) and status (status attribute of the c:forEach tag) in the JSP fragment of the body row.

<n:set var="rowCount" value="${status.count}" />
<n:write name="rowCount" />

In addition, the following attributes are provided in the body row that specify the class attribute for changing the background color of every other row.

An example of project search specifications is shown below. The tag file prefix should be app.

<app:listSearchResult resultSetName="searchResult">

   <%-- JSP fragment specification for header line. --%>
   <jsp:attribute name="headerRowFragment">
       <tr>
           <th>Project id</th>
           <th>Project name</th>
           <th>Project type</th>
           <th>Start date</th>
           <th>End date</th>
       </tr>
   </jsp:attribute>

   <%-- Body line JSP fragment specification. --%>
   <jsp:attribute name="bodyRowFragment">
       <tr class="info">
           <td>
               <%-- Access the row data using the default variable name "row". --%>
               <n:a href="/action/project/show/${row.projectId}">
                   <n:write name="row.projectId"/>
               </n:a>
           </td>
           <td>
               <n:write name="row.projectName" />
           </td>
           <td>
               <c:forEach var="projectType" items="<%= ProjectType.values() %>">
                   <c:if test="${projectType.code == row.projectType}">
                       <n:write name="projectType.label" />
                   </c:if>
               </c:forEach>
           </td>
           <td>
               <n:write value="${n:formatByDefault('dateTime', row.projectStartDate)}" />
           </td>
           <td>
               <n:write value="${n:formatByDefault('dateTime', row.projectEndDate)}" />
           </td>
       </tr>
   </jsp:attribute>
</app:listSearchResult>

The search results after the above specifications are shown below.

listSearchResult tag¶

The listSearchResult tag displays a list of search results. The attributes for each screen element are shown below.

<n:set var="rowCount" value="${status.count}" />
<n:write name="rowCount" />