Re: [xwiki-devs] What is $msg ? - xwiki-devs@xwiki.org

17 Apr 2008

...

 Message: 8
 Date: Wed, 16 Apr 2008 23:27:57 +0200
 From: "Guillaume Lerouge" &lt;guillaume(a)xwiki.com&gt;
 Subject: Re: [xwiki-devs] What is $msg ?
 To: "XWiki Developers" &lt;devs(a)xwiki.org&gt;
 Message-ID:
        &lt;1c35d2320804161427n3f69229bs6d2bb425d00e13c1(a)mail.gmail.com&gt;
 Content-Type: text/plain; charset=ISO-8859-1

 Hi Kamna,

 In the past few days, I have been looking a lot at the Velocity templates
  and the Xwiki core code.
 There are a few things I am not able to understand.

 1) Where is $msg variable defined in the core code? I see it a lot in  the
  scripts. Is it a hashtable for messages. Where is
it defined? 

 $msg is the code used to get translation messages. Basically when you
 write
 $msg.translation or $msg.get("translation"), upon parsing of the page by
 the
 Velovity parser the engine looks into the translations file. if it finds
 something such as translation=NiceTranslation, it turns $msg.translation
 into NiceTranslation when rendering the page.

 2) what is referred to by "xpage","xredirect"

 For eg. in the following mehtod from Utils.java

 public static String getPage(XWikiRequest request, String defaultpage)
    {
        String page;
        page = request.getParameter("xpage");
        if ((page == null) || (page.equals(""))) {
            page = defaultpage;
        }
        return page;
    }

 does this mean, that if a page with that name exists in the template
 directory(xpage), it will be returned. But, what is defaultpage?

 They are used to return specific actions when ?xpage= is appended to a
 page
 URL . For instance, /xwiki/bin/view/Main/WebHome?xpage=plain will render
 the
 content witout any style, /xwiki/bin/view/Main/WebHome?xpage=print will
 render the page in print mode...

 Similarly, ?xredirect takes another url as a parameter and sends the
 viewer
 to the given page. When you try to access a page you cannot see, it's the
 action used to send you back to the page from the login page.
 if xpage = "mypage" then it would pass the control (request) to a vm
template file mypage.vm and the rendering or response of the request would
be  as defined in mypage.vm

...

  Currently the login page does not show any error
if the provided
 credentials
 are wrong. (authentication with LDAP)
 A look at the LoginErrorAction.java in the Web package revealed that it
 returns the same string as the LoginAction - "login"
 so, if I created anither loginerror.vm in teh templates folder and
 returned
 "loginerror" in the render function of this LoginErrorAction.java class,
 it
 would run the new script.

 But, at this stage I do not know what would be the content of the
 loginerror.vm....
 #xwikimessageboxstart($msg.get("error") $msg.get("notallowed"))  -
would
 this work? 

 Not quite sure... Though trial & error sounds like a nice tactic ;-)

 Guillaume