com.uwyn.rife.site
Class PagedNavigation

java.lang.Object
  com.uwyn.rife.site.PagedNavigation

public class PagedNavigation
extends Object

This class provides utility methods to generate navigation for paged lists.

The generation of the navigation depends on a collection of block and value IDs that should be defined in a template. Following is a table of all the IDs and their purpose:

ID	Description
<!--B 'NAV:FIRSTRANGE'--><!--/B-->	Provides the content that will be used to jump to the first range. This block has to contain an EXIT:QUERY value that will be replaced with the actual URL that will trigger the paging behaviour.
<!--B 'NAV:FIRSTRANGE:DISABLED'--><!--/B-->	Provides the content that will be used when jumping to the first range is not appropriate, for instance when the first range is already the current offset.
<!--B 'NAV:PREVIOUSRANGE'--><!--/B-->	Provides the content that will be used to jump to the previous range according to the current offset. This block has to contain an EXIT:QUERY value that will be replaced with the actual URL that will trigger the paging behaviour.
<!--B 'NAV:PREVIOUSRANGE:DISABLED'--><!--/B-->	Provides the content that will be used when jumping to the previous range is not appropriate, for instance when the first range is the current offset.
<!--B 'NAV:ABSOLUTERANGE'--><!--/B-->	Provides the content that will be used to jump directly to each individual range. This block has to contain an EXIT:QUERY value that will be replaced with the actual URL that will trigger the paging behaviour.
<!--B 'NAV:ABSOLUTERANGE:DISABLED'--><!--/B-->	Provides the content that will be used when jumping directly to a specific individual range is not appropriate, for instance when that range corresponds to the current offset.
<!--B 'NAV:NEXTRANGE'--><!--/B-->	Provides the content that will be used to jump to the next range according to the current offset. This block has to contain an EXIT:QUERY value that will be replaced with the actual URL that will trigger the paging behaviour.
<!--B 'NAV:NEXTRANGE:DISABLED'--><!--/B-->	Provides the content that will be used when jumping to the next range is not appropriate, for instance when the last range is the current offset.
<!--B 'NAV:LASTRANGE'--><!--/B-->	Provides the content that will be used to the last range. This block has to contain an EXIT:QUERY value that will be replaced with the actual URL that will trigger the paging behaviour.
<!--B 'NAV:LASTRANGE:DISABLED'--><!--/B-->	Provides the content that will be used when jumping to the last range is not appropriate, for instance when the last range is already the current offset.
<!--V 'NAV:RANGECOUNT'/-->	Will contain the number of ranges that are needed to display all the information that is paged. This value is optional.
<!--V 'NAV:FIRSTRANGE'/-->	Will contain the content that allows to jump to the first range. This corresponds to the beginning of the paged data.
<!--V 'NAV:PREVIOUSRANGE'/-->	Will contain the content that allows to jump to the previous range according to the current offset.
<!--V 'NAV:ABSOLUTERANGES'/-->	Will contain the content that allows to jump directly to each individual range that is available.
<!--V 'NAV:NEXTRANGE'/-->	Will contain the content that allows to jump to the next range according to the current offset.
<!--V 'NAV:LASTRANGE'/-->	Will contain the content that allows to jump to the last range. This corresponds to the end of the paged data.

Besides these template conventions, you also have to provide one exit and one output that will be used to create the links that will perform the actual paging behaviour of the navigation. By default, the change_offset exit and the offset output will be used. It's up to you to create the datalink and flowlink and to correctly handle the offset value when it changes.

A very basic paged navigation could for example be defined like this:

<!--B 'NAV:FIRSTRANGE'--><a href="[!V 'EXIT:QUERY:change_offset'/]">&lt;&lt;</a><!--/B-->
<!--B 'NAV:FIRSTRANGE:DISABLED'-->&lt;&lt;<!--/B-->
<!--B 'NAV:PREVIOUSRANGE'--><a href="[!V 'EXIT:QUERY:change_offset'/]">&lt;</a><!--/B-->
<!--B 'NAV:PREVIOUSRANGE:DISABLED'-->&lt;<!--/B-->
<!--B 'NAV:ABSOLUTERANGE'-->&nbsp;<a href="[!V 'EXIT:QUERY:change_offset'/]"><!--V 'ABSOLUTERANGE_TEXT'/--></a>&nbsp;<!--/B-->
<!--B 'NAV:ABSOLUTERANGE:DISABLED'-->&nbsp;<!--V 'ABSOLUTERANGE_TEXT'/-->&nbsp;<!--/B-->
<!--B 'NAV:NEXTRANGE'--><a href="[!V 'EXIT:QUERY:change_offset'/]">&gt;</a><!--/B-->
<!--B 'NAV:NEXTRANGE:DISABLED'-->&gt;<!--/B-->
<!--B 'NAV:LASTRANGE'--><a href="[!V 'EXIT:QUERY:change_offset'/]">&gt;&gt;</a><!--/B-->
<!--B 'NAV:LASTRANGE:DISABLED'-->&gt;&gt;<!--/B-->

Pages: <!--V 'NAV:RANGECOUNT'/--> ( <!--V 'NAV:FIRSTRANGE'/--> <!--V 'NAV:PREVIOUSRANGE'/--> <!--V 'NAV:NEXTRANGE'/--> <!--V 'NAV:LASTRANGE'/--> | <!--V 'NAV:ABSOLUTERANGES'/--> )

Which could result in the following output where all the underlined parts are clickable and will trigger the change_offset exit and provide a new corresponding value for the offset output:

Pages: 9 ( << < > >> | 1 2 3 4 5 6 7 8 9 )

The element that displays the list and calls the navigation generation method could for example be like this:

public class List extends Element
{
    public final static int LIMIT = 10;
    public final static int SPAN = 5;

    public void processElement()
    {
        Template t = getHtmlTemplate("article.list");
        DatabaseArticles manager = DatabaseArticlesFactory.getInstance();

        int count = manager.countArticles();
        if (0 == count) t.setBlock("content", "noarticles");
        else
        {
            int offset = getInputInt("offset", 0);

            PagedNavigation.generateNavigation(this, t, count, LIMIT, offset, SPAN);

            Collection<Article> articles = manager.listArticles(LIMIT, offset);
            for (Article article : articles)
            {
                t.setBean(article);
                t.appendBlock("articles", "article");
            }
        }

        print(t);
    }
}

Field Summary

static String	DEFAULT_EXIT
static String	DEFAULT_OUTPUT
static String	ID_ABSOLUTERANGE
static String	ID_ABSOLUTERANGE_DISABLED
static String	ID_ABSOLUTERANGE_TEXT
static String	ID_ABSOLUTERANGES
static String	ID_FIRSTRANGE
static String	ID_FIRSTRANGE_DISABLED
static String	ID_LASTRANGE
static String	ID_LASTRANGE_DISABLED
static String	ID_NEXTRANGE
static String	ID_NEXTRANGE_DISABLED
static String	ID_PREVIOUSRANGE
static String	ID_PREVIOUSRANGE_DISABLED
static String	ID_RANGECOUNT
static String	PREFIX_NAV
static String	SUFFIX_DISABLED

Constructor Summary

PagedNavigation()

Method Summary

static void	generateNavigation(ElementSupport element, Template template, long count, int limit, long offset, int span) Generates the paged navigation for the given element, template and range configuration.
static void	generateNavigation(ElementSupport element, Template template, long count, int limit, long offset, int span, String exit, String output) Generates the paged navigation for the given element, template and range configuration.
static void	generateNavigation(ElementSupport element, Template template, long count, int limit, long offset, int span, String exit, String output, String pathInfo) Generates the paged navigation for the given element, template and range configuration.

Methods inherited from class java.lang.Object

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

Field Detail

PREFIX_NAV

public static String PREFIX_NAV

SUFFIX_DISABLED

public static String SUFFIX_DISABLED

ID_RANGECOUNT

public static String ID_RANGECOUNT

ID_ABSOLUTERANGE_TEXT

public static String ID_ABSOLUTERANGE_TEXT

ID_FIRSTRANGE

public static String ID_FIRSTRANGE

ID_PREVIOUSRANGE

public static String ID_PREVIOUSRANGE

ID_ABSOLUTERANGES

public static String ID_ABSOLUTERANGES

ID_ABSOLUTERANGE

public static String ID_ABSOLUTERANGE

ID_NEXTRANGE

public static String ID_NEXTRANGE

ID_LASTRANGE

public static String ID_LASTRANGE

ID_FIRSTRANGE_DISABLED

public static String ID_FIRSTRANGE_DISABLED

ID_PREVIOUSRANGE_DISABLED

public static String ID_PREVIOUSRANGE_DISABLED

ID_ABSOLUTERANGE_DISABLED

public static String ID_ABSOLUTERANGE_DISABLED

ID_NEXTRANGE_DISABLED

public static String ID_NEXTRANGE_DISABLED

ID_LASTRANGE_DISABLED

public static String ID_LASTRANGE_DISABLED

DEFAULT_EXIT

public static String DEFAULT_EXIT

DEFAULT_OUTPUT

public static String DEFAULT_OUTPUT

Constructor Detail

PagedNavigation

public PagedNavigation()

Method Detail

generateNavigation

public static void generateNavigation(ElementSupport element,
                                      Template template,
                                      long count,
                                      int limit,
                                      long offset,
                                      int span)

Generates the paged navigation for the given element, template and range configuration. The default exit change_offset and the default output offset will be used when generating the links.

Parameters:

element - The element that is populating the template. Its exit will be triggered and its output will be set.

template - The template that will be used for the generation of the navigation.

count - The total number of items that are being paged.

limit - The maximum of items that will be shown in a range on a page.

offset - The starting offset of the range that is currently visible.

span - The maximum number of ranges that will be shown as immediately accesible absolute ranges.

generateNavigation

public static void generateNavigation(ElementSupport element,
                                      Template template,
                                      long count,
                                      int limit,
                                      long offset,
                                      int span,
                                      String exit,
                                      String output)

Generates the paged navigation for the given element, template and range configuration. This version allows you to provide your own names for the exit and the output that will be used when generating the links.

Parameters:

element - The element that is populating the template, whose exit will be triggered and whose output will be set.

template - The template that will be used for the generation of the navigation.

count - The total number of items that are being paged.

limit - The maximum of items that will be shown in a range on a page.

offset - The starting offset of the range that is currently visible.

span - The maximum number of ranges that will be shown as immediately accesible absolute ranges.

exit - The name of the exit that has to be used to trigger an offset change.

output - The name of the output that will contain the value of the new range offset when the exit is triggered.

generateNavigation

public static void generateNavigation(ElementSupport element,
                                      Template template,
                                      long count,
                                      int limit,
                                      long offset,
                                      int span,
                                      String exit,
                                      String output,
                                      String pathInfo)

Generates the paged navigation for the given element, template and range configuration. This version allows you to provide your own names for the exit and the output that will be used when generating the links.

Parameters:

element - The element that is populating the template, whose exit will be triggered and whose output will be set.

template - The template that will be used for the generation of the navigation.

count - The total number of items that are being paged.

limit - The maximum of items that will be shown in a range on a page.

offset - The starting offset of the range that is currently visible.

span - The maximum number of ranges that will be shown as immediately accesible absolute ranges.

exit - The name of the exit that has to be used to trigger an offset change.

output - The name of the output that will contain the value of the new range offset when the exit is triggered.

pathInfo - The pathinfo to be applied to the exit used to trigger an offset change