Java Doc for CommandResolver.java in  » Wiki-Engine » JSPWiki » com » ecyrd » jspwiki » ui » Java Source Code / Java DocumentationJava Source Code and Java Documentation

Resolves special pages, JSPs and Commands on behalf of a WikiEngine. CommandResolver will automatically resolve page names with singular/plural variants. It can also detect the correct Command based on parameters supplied in an HTTP request, or due to the JSP being accessed.

CommandResolver's static CommandResolver.findCommand(String) method is the simplest method; it looks up and returns the Command matching a supplied wiki context. For example, looking up the request context view returns PageCommand.VIEW . Use this method to obtain static Command instances that aren't targeted at a particular page or group.

For more complex lookups in which the caller supplies an HTTP request, CommandResolver.findCommand(HttpServletRequest,String) will look up and return the correct Command. The String parameter defaultContext supplies the request context to use if it cannot be detected. However, note that the default wiki context may be over-ridden if the request was for a "special page."

For example, suppose the WikiEngine's properties specify a special page called UserPrefs that redirects to UserPreferences.jsp. The ordinary lookup method using a supplied context view would return PageCommand.VIEW . But the method, when passed the same context (view) and an HTTP request containing the page parameter value UserPrefs, will instead return WikiCommand.PREFS .

Attempts to locate a Command for a supplied wiki context and HTTP request, incorporating the correct WikiPage into the command if reqiured. This method will first determine what page the user requested by delegating to CommandResolver.extractPageFromParameter(String,HttpServletRequest) .

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.

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.

• 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

Attempts to locate a Command for a supplied wiki context and HTTP request, incorporating the correct WikiPage into the command if reqiured. 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.

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.

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".