org.jivesoftware.util

Class ListPager<T>

java.lang.Object

org.jivesoftware.util.ListPager<T>

Type Parameters:

T - The type of item being displayed

public class ListPager<T>
extends Object

This class provides an easy way to page through a filterable list of items from a JSP page.

It is up to the caller of the class to specify the filter, if required, in the form of a predicate. To ensure that search parameters are maintained when paging through the list, it's also necessary to supply a list of input field identifiers that should be included as part of the request when accessing another page. These field identifiers are used to extract the value of the field, and copy it to a hidden form that is used for the actual submission. This means each search criteria has two form fields associated with it - the visible field that the users types in, and in the hidden form that is submitted.

The reason for this is that the location of the input fields on the screen may not always be appropriate for a form - for example, if the fields are location within a table, the form must wrap the whole table, which would preclude the use of any other forms within cells in that table.

These input fields will also be modified so that pressing Enter/Return when the fields has focus will automatically submit the form.

Constructor Summary

Constructors

Constructor and Description
ListPager(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, List<T> items, Predicate<T> filter, String... additionalFormFields) Creates a unfiltered list pager.
ListPager(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, List<T> items, String... additionalFormFields) Creates a unfiltered list pager.

Method Summary

Modifier and Type	Method and Description
int	getCurrentPageNumber()
int	getFilteredItemCount()
int	getFirstItemNumberOnPage()
String	getHiddenFields()
List<T>	getItemsOnCurrentPage()
String	getJumpToPageForm()
int	getLastItemNumberOnPage()
String	getPageFunctions()
String	getPageLinks()
int	getPageSize()
String	getPageSizeSelection()
static String	getQueryString(javax.servlet.http.HttpServletRequest request, char prefix, String... additionalFormFields)
int	getTotalItemCount()
int	getTotalPages()
boolean	isFiltered()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ListPager

public ListPager(javax.servlet.http.HttpServletRequest request,
                 javax.servlet.http.HttpServletResponse response,
                 List<T> items,
                 String... additionalFormFields)

Creates a unfiltered list pager.

Parameters:

request - the request object for the page in question

response - the response object for the page in question

items - the list of items to display on the page

additionalFormFields - 0 or more input field identifiers (NOT form field names) to include in requests for other pages

ListPager

public ListPager(javax.servlet.http.HttpServletRequest request,
                 javax.servlet.http.HttpServletResponse response,
                 List<T> items,
                 Predicate<T> filter,
                 String... additionalFormFields)

Creates a unfiltered list pager.

Parameters:

request - the request object for the page in question

response - the response object for the page in question

items - the complete list of items to display on the page

filter - the filter to apply to the complete list

additionalFormFields - 0 or more input field identifiers (NOT form field names) to include in requests for other pages

Method Detail

getTotalItemCount

public int getTotalItemCount()

Returns:

the total number unfiltered items

getFilteredItemCount

public int getFilteredItemCount()

Returns:

the number of items after the filter has been applied

getItemsOnCurrentPage

public List<T> getItemsOnCurrentPage()

Returns:

the filtered items on the current page

getCurrentPageNumber

public int getCurrentPageNumber()

Returns:

the current page

getPageSize

public int getPageSize()

Returns:

the maximum number of items on the page

getFirstItemNumberOnPage

public int getFirstItemNumberOnPage()

Returns:

the first item number on the page

getLastItemNumberOnPage

public int getLastItemNumberOnPage()

Returns:

the last item number on the page

getTotalPages

public int getTotalPages()

Returns:

the total number of pages

isFiltered

public boolean isFiltered()

Returns:

true if the the supplied filter has restricted the number of items to display, otherwise false

getPageSizeSelection

public String getPageSizeSelection()

Returns:

a string that contains HTML for selecting the page size

getPageLinks

public String getPageLinks()

Returns:

a string that contains links to other pages in the list

getHiddenFields

public String getHiddenFields()

Returns:

the list of hidden fields required to maintain the current list pager state

getQueryString

public static String getQueryString(javax.servlet.http.HttpServletRequest request,
                                    char prefix,
                                    String... additionalFormFields)

Parameters:

request - The request to retrieve the values from

prefix - The first char of the query string - either `?` or `&`

additionalFormFields - 0 or more form field names to include in requests for other pages

Returns:

a query string required to maintain the current list pager state

getJumpToPageForm

public String getJumpToPageForm()

Returns:

a string with an HTML form containing hidden fields, used for navigating between pages

getPageFunctions

public String getPageFunctions()

Returns:

a string containing JavaScript that helps with navigation between pages