admins (advanced)
This page describes an internal function in PmWiki's engine called
FmtPageName(). The contents are not intended for those with a weak heart
;-)

 

Also see: PmWiki.Functions

 

FmtPageName($fmt, $pagename)

 

Returns $fmt, with $variable and internationalisation substitutions performed, under the assumption that the current page is pagename. See PmWiki.Variables for an (incomplete) list of available variables, PmWiki.Internationalizations for internationalisation.

 

The function FmtPageName() applies internationalization-substitutions
and $Variable-substitions to the string $fmt under the assumption that the
current page is $pagename.

 

The substitutions goes as follows:

 

  1. Replace any sequences of the form $XyzFmt with value of any   corresponding global variable.
  2. Process the string for any $[...] phrases (internationalized phrase),   using the currently loaded translation tables.
  3. Perform any pattern replacements from the array $FmtP. Typically   this is used to handle things like $Name and $Group etc that are   specific to the name of the current page.
  4. If $EnablePathInfo isn't set, convert URIs to use the syntax   $ScriptUrl?n=<Group>.<Name> instead of $ScriptUrl/<Group>/<Name>.
  5. Replace any $-sequences with global variables (caching as needed)   of the same name (in reverse alphabetical order) *
  6. Replace any $-sequences with values out of the array $FmtV.

 

Note that FmtPageName() is automatically aware of any global
variables. However, since modifying global variables may be expensive, the
array $FmtV exists as a way to avoid rebuilding the variable cache for
values that change frequently.

 

 

To be very specific, here's what Pm wrote regarding different ways of
defining a variable that can be used by FmtPageName (when it is formatting a
string):

 

  • Set a global variable.  FmtPageName() automatically performs   substitution on all global variables that aren't arrays.   If the variable is going to change value over repeated calls   to FmtPageName, it's probably better to use $FmtV as in the next item.

 

  • Set a value in the $FmtV array.  $FmtV(:cell PQA(PSS('$MyVariable'):)='something'    means to replace instances of '$MyVariable' with 'something'.   Use this for variables that change value frequently over   multiple calls to FmtPageName.  

 

  • Set a pattern/replacement in the $FmtP array.  This is normally   done for substitutions that have to be dynamic somehow based on   the pagename being referenced, such as '$Title', '$Group', '$Name',   '$PageUrl', etc.

 

Also see: Cookbook:Functions#FmtPageName

 

Finally, here's something else Pm wrote that is related and explains
why we have this function:

 

In order to produce its output, PmWiki has to do a variety of string    substitutions:

 

  1. Generating the full name, group, title, or url of a page     (other than the currently displayed page)
  2. Substituting the values of global variables
  3. Performing internationalization substitutions
  4. Converting $ScriptUrl/$Group/$Name to $ScriptUrl?n=$Group.$Name    for sites that cannot handle PATH_INFO urls
  5. Other substitutions needed by specific functions

 

PmWiki centralizes all of that substitute-a-dynamic-value-in-a-string    into the FmtPageName() subroutine.  Because some things are extremely    dynamic, such as the url or group for an arbitrary page that is not the    current one, those things cannot be simple global PHP variables.  Or, if    they do become global variables, they're variables that cannot be    trusted to hold a value for very long because some other routine (that    may happen to be formatting a string for a different page) will come    along and change that global variable for whatever it happens to be doing.

 

A limited set of $-substitutions -- basically anything that     corresponds to a page attribute -- are not PHP variables and     are only available through the FmtPageName() subroutine.      The complete set of these special substitutions is $Group,     $Name, $FullName, $PageUrl, $Title, $Titlespaced, $Namespaced,     $Groupspaced, $LastModifiedBy, $LastModifiedHost, and $LastModified.      These items cannot just be standard PHP variables because often    PmWiki needs to obtain the url, name, group, title, etc. of a page     other than the one currently being viewed by a browser.

 

At the moment, $Title, $LastModified, $LastModifiedBy, and     $LastModifiedHost can only work if the page's attributes have been     loaded and cached using the PCache function.   So, to get    at these values one must typically do:

 

$page = `ReadPage($pagename);
PCache($pagename, $page);
$pvar = `FmtPageName('$Title', $pagename);
$pvar = `FmtPageName('$`LastModifiedBy', $pagename);

 

Source code for FmtPageName()

 

Note: The source code below was taken from "pmwiki-2.0.beta55", while the
current version is pmwiki-2.1.27.

 

## FmtPageName handles $[internationalization] and $Variable
## substitutions in strings based on the $pagename argument.
function FmtPageName($fmt,$pagename) {
  # Perform $-substitutions on $fmt relative to page given by $pagename
  global $GroupPattern, $NamePattern, $EnablePathInfo, $ScriptUrl,
    $GCount, $UnsafeGlobals, $FmtV, $FmtP, $PCache, $AsSpacedFunction;
  if (strpos($fmt,'$')===false) return $fmt;
  $fmt = preg_replace('/\\$([A-Z]\\w*Fmt)\\b/e','$GLOBALS[\'$1\']',$fmt);
  $fmt = preg_replace('/\\$\\[(?>([^\\]] ))\\]/e',"XL(PSS('$1'))",$fmt);
  $match = array('','$Group','$Name');
  if (preg_match("/^($GroupPattern)[\\/.]($NamePattern)\$/", $pagename, $m))
    $match = $m;
  $fmt = preg_replace(array_keys($FmtP),array_values($FmtP),$fmt);
  $fmt = preg_replace('!\\$ScriptUrl/([^?#\'"\\s<>] )!e',
    (@$EnablePathInfo) ? "'$ScriptUrl/'.PUE('$1')" :
        "'$ScriptUrl?n='.str_replace('/','.',PUE('$1'))",
    $fmt);
  if (strpos($fmt,'$')===false) return $fmt;
  static $g;
  if ($GCount != count($GLOBALS) count($FmtV)) {
    $g = array();
    foreach($GLOBALS as $n=>$v) {
      if (is_array($v) || is_object($v) ||
         isset($FmtV["\$$n"]) || in_array($n,$UnsafeGlobals)) continue;
      $g["\$$n"] = $v;
    }
    $GCount = count($GLOBALS) count($FmtV);
    krsort($g); reset($g);
  }
  $fmt = str_replace(array_keys($g),array_values($g),$fmt);
  $fmt = str_replace(array_keys($FmtV),array_values($FmtV),$fmt);
  return $fmt;
}


Page last modified on May 06, 2006, at 03:41 AM