org.apache.wiki.ui

Class DefaultCommandResolver

java.lang.Object

org.apache.wiki.ui.DefaultCommandResolver

All Implemented Interfaces:

CommandResolver

public class DefaultCommandResolver
extends java.lang.Object
implements CommandResolver

Default implementation for CommandResolver

Since:

2.4.22

Field Summary

Fields inherited from interface org.apache.wiki.ui.CommandResolver

PROP_SPECIALPAGE

Constructor Summary

Constructors

Constructor and Description
DefaultCommandResolver(Engine engine, java.util.Properties properties) Constructs a CommandResolver for a given Engine.

Method Summary

Modifier and Type	Method and Description
protected Command	extractCommandFromPath(javax.servlet.http.HttpServletRequest request) Extracts a Command based on the JSP path of an HTTP request.
java.lang.String	extractPageFromParameter(java.lang.String requestContext, javax.servlet.http.HttpServletRequest request) Determines the correct wiki page based on a supplied request context and HTTP request.
Command	findCommand(javax.servlet.http.HttpServletRequest request, java.lang.String defaultContext) Attempts to locate a Command for a supplied wiki context and HTTP request, incorporating the correct WikiPage into the command if required.
java.lang.String	getFinalPageName(java.lang.String page) Returns the correct page name, or null, if no such page can be found.
java.lang.String	getSpecialPageReference(java.lang.String page) If the page is a special page, this method returns a direct URL to that page; otherwise, it returns null.
Page	resolvePage(javax.servlet.http.HttpServletRequest request, java.lang.String page) Looks up and returns the correct, versioned WikiPage based on a supplied page name and optional version parameter passed in an HTTP request.
protected boolean	simplePageExists(java.lang.String page) Determines whether a "page" exists by examining the list of special pages and querying the page manager.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.wiki.ui.CommandResolver

findCommand

Constructor Detail

DefaultCommandResolver

public DefaultCommandResolver(Engine engine,
                              java.util.Properties properties)

Constructs a CommandResolver for a given Engine. This constructor will extract the special page references for this wiki and store them in a cache used for resolution.

Parameters:

engine - the wiki engine

properties - the properties used to initialize the wiki

Method Detail

findCommand

public Command findCommand(javax.servlet.http.HttpServletRequest request,
                           java.lang.String defaultContext)

Attempts to locate a Command for a supplied wiki context and HTTP request, incorporating the correct WikiPage into the command if required. This method will first determine what page the user requested by delegating to CommandResolver.extractPageFromParameter(String, HttpServletRequest). If this page equates to a special page, we return the Command corresponding to that page. Otherwise, this method simply returns the Command for the supplied request context.

The reason this method attempts to resolve against special pages is because some of them resolve to contexts that may be different from the one supplied. For example, a VIEW request context for the special page "UserPreferences" should return a PREFS context instead.

When the caller supplies a request context and HTTP request that specifies an actual wiki page (rather than a special page), this method will return a "targeted" Command that includes the resolved WikiPage as the target. (See CommandResolver.resolvePage(HttpServletRequest, String) for the resolution algorithm). Specifically, the Command will return a non-null value for its AbstractCommand.getTarget() method.

Note: if this method determines that the Command is the VIEW PageCommand, then the Command returned will always be targeted to the front page.

Specified by:

findCommand in interface CommandResolver

Parameters:

request - the HTTP request; if null, delegates to CommandResolver.findCommand(String)

defaultContext - the request context to use by default

Returns:

the resolved wiki command

getFinalPageName

public java.lang.String getFinalPageName(java.lang.String page)
                                  throws ProviderException

Returns the correct page name, or null, if no such page can be found. Aliases are considered.

In some cases, page names can refer to other pages. For example, when you have matchEnglishPlurals set, then a page name "Foobars" will be transformed into "Foobar", should a page "Foobars" not exist, but the page "Foobar" would. This method gives you the correct page name to refer to.

This facility can also be used to rewrite any page name, for example, by using aliases. It can also be used to check the existence of any page.

Specified by:

getFinalPageName in interface CommandResolver

Parameters:

page - the page name.

Returns:

The rewritten page name, or null, if the page does not exist.

Throws:

ProviderException - if the underlyng page provider that locates pages throws an exception

getSpecialPageReference

public java.lang.String getSpecialPageReference(java.lang.String page)

If the page is a special page, this method returns a direct URL to that page; otherwise, it returns null.

Special pages are non-existant references to other pages. For example, you could define a special page reference "RecentChanges" which would always be redirected to "RecentChanges.jsp" instead of trying to find a Wiki page called "RecentChanges".

Specified by:

getSpecialPageReference in interface CommandResolver

Parameters:

page - the page name ro search for

Returns:

the URL of the special page, if the supplied page is one, or null

extractCommandFromPath

protected Command extractCommandFromPath(javax.servlet.http.HttpServletRequest request)

Extracts a Command based on the JSP path of an HTTP request. If the JSP requested matches a Command's getJSP() value, that Command is returned.

Parameters:

request - the HTTP request

Returns:

the resolved Command, or null if not found

extractPageFromParameter

public java.lang.String extractPageFromParameter(java.lang.String requestContext,
                                                 javax.servlet.http.HttpServletRequest request)

Determines the correct wiki page based on a supplied request context and HTTP request. This method attempts to determine the page requested by a user, taking into acccount special pages. The resolution algorithm will:

• Extract the page name from the URL according to the rules for the current URLConstructor. If a page name was passed in the request, return the correct name after taking into account potential plural matches.
• If the extracted page name is null, attempt to see if a "special page" was intended by examining the servlet path. For example, the request path "/UserPreferences.jsp" will resolve to "UserPreferences."
• If neither of these methods work, this method returns null

Specified by:

extractPageFromParameter in interface CommandResolver

Parameters:

requestContext - the request context

request - the HTTP request

Returns:

the resolved page name

resolvePage

public Page resolvePage(javax.servlet.http.HttpServletRequest request,
                        java.lang.String page)

Looks up and returns the correct, versioned WikiPage based on a supplied page name and optional version parameter passed in an HTTP request. If the version parameter does not exist in the request, the latest version is returned.

Specified by:

resolvePage in interface CommandResolver

Parameters:

request - the HTTP request

page - the name of the page to look up; this page must exist

Returns:

the wiki page

simplePageExists

protected boolean simplePageExists(java.lang.String page)
                            throws ProviderException

Determines whether a "page" exists by examining the list of special pages and querying the page manager.

Parameters:

page - the page to seek

Returns:

true if the page exists, false otherwise

Throws:

ProviderException - if the underlyng page provider that locates pages throws an exception