RAC Syllabi : Page Text Variables browse

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Defining page text variables
Usage

Page text variables are string variables created in the wiki text of a page, and can be automatically made available for inclusion in other pages. In the default installation, PageTextVariables can only have a name containing basic Latin/Roman (ASCII) letters, digits, dash and underscore. This is a limitation for international wikis (experimental recipe for international PTV : Cookbook:InternationalPTVs).

Defining Page Text Variables

There are three ways to define automated Page Text Variables (more patterns can be defined if needed) :

use a definition list - the normal pmwiki markup for a definition list will create a page text variable

Example definition list:
`:Name: Crisses "{$:Name}"`	Name Crisses "Crisses"

This creates a new variable that can be accessed by {$:Name} (becomes: "Crisses") in the page.

use a simple colon delimiter in normal text

Example colon delimited:
`Address: 1313 Mockingbird Lane "{$:Address}"`	Address: 1313 Mockingbird Lane "1313 Mockingbird Lane"

This creates the {$:Address} variable (variable markup becomes: "1313 Mockingbird Lane") in the page.

hidden directive form - PmWiki markup that doesn't render on the page, but defines the variable

Example directive:
`(:Country: Transylvania :) "{$:Country}"`	"Transylvania "

This creates the {$:Country} variable (variable markup becomes: "Transylvania ") in the page.

Usage

Usage on the same page

On the same page you can resolve page text variables through the {$:Var} format (shown above).

Usage in headers and footers: special references

If you want a GroupHeader, GroupFooter, SideBar, etc to call on page text variable in the main page, you need to include special reference information. To explicitly reference the page text variable from the page being displayed add an asterisk to the page text variable's markup: {*$:Address} on the GroupFooter or GroupHeader page.

Example
`{$:Mountain} \\ {$Namespaced}`	Mt Ruapehu Page Text Variables

To include a page text variable from a header or footer see usage from other pages below.

Special references also apply to page variables and page list templates.

Usage from other pages

If you want to pull the data from another page, use the {Group/PageName$:Var} format.

Example:
`Suburb: Khandallah (:Lake:Taupo:) :Mountain:Mt Ruapehu ->"{PmWiki/PageTextVariables$:Suburb}" ->"{{$FullName}$:Lake}" ->"{PmWiki/PageTextVariables$:Mountain}"`	Suburb: Khandallah Mountain Mt Ruapehu "Khandallah" "Taupo" "Mt Ruapehu"

Usage from included pages

Page text variables are never included from their source page. See Usage from other pages above to refer to a page text variable on another page.

Usage with pagelists

Page lists can also access the page text variables:

Example:
`(:pagelist group=PmWiki order=$:Summary count=6 fmt=#singleline:)`	WikiFarmTerminology, WikiAdministrator, SpecialCharacters, PatrickMichaud, PmWiki, WikiSandbox,

And to create pagelist formats (such as those documented at Site.Page List Templates, Page Lists, Page List Templates, Page Variables. Store custom pagelists at Site.Local Templates ?).

Page lists can also use page text variables to select pages :

Example:
`(:pagelist group=PmWiki $:City=Paris count=8 fmt=#singleline order=-name:)`

lists pages having '$:City' set to 'Paris'.

Example: multiple selections with spaces
`(:pagelist group=PmWiki $:City="Addis Ababa,Paris" order=-$:Version count=8 fmt=#singleline:)`

'quotes' must surround all the selections.

When using page text variables for selection or ordering, don't put the curly braces around the variable name. The curly forms do a replacement before the pagelist command is evaluated.
Link markup within the contents of a hidden page text variable directive (as opposed to other ways of specifying PTVs) will not be cached as a link on the page and thus won't be seen by pagelist's link= option. If you want the link to be found by link=, you need to specify the PTV using non-directive markup, or else put the link on the page even if it's hidden within a false conditional: (:Linkme: [[PageToLink]]:) (:if false:){$:Linkme}(:ifend:)

The page text variable value is always the text that is written in the page. It is only evaluated when the variable is printed/output to HTML. To sort by a page text variable variable, all values in all pages are the not-yet-evaluated text strings, and the pagelist order function does what it can with them. It does not process/evaluate the text at this point.

E.g. With a page name in to format "yyyyMonth" it is simpler to use a PageVariable calculated in config.php, not a PageTextVariable:

$FmtPV['$NameToYearMonth'] = 'strftime("%Y%m", strtotime($name))';

Then use (:pagelist order=$NameToYearMonth:)

An alternative is writing in the wiki page:

(:MonthNum:07:)

as the markup expression that follows won't work:

(:MonthNum:{(ftime fmt=%m when="{$Namespaced}")}:)

Testing if set or not set

=-	PTV is set (is not empty), eg `(:pagelist $:Var=- :)`
=-?*	PTV is not set (is empty), ie not one character followed by 0 or more characters, eg. `(:pagelist $:Var=-?* :)`
=*	display all pages, regardless of the page text variable (slow)
=-*	display no pages, regardless of the page text variable (slow)

Tip : (:if ! equal "{$:PTV}" "":) will test if PTV is empty/unset or not.

Example: Pages without a summary
`(:pagelist group=PmWiki $:Summary=-?* count=6 fmt=#singleline:)`	PatrickMichaud, PmWiki, SpecialCharacters, WikiAdministrator, WikiFarmTerminology, WikiSandbox,

Use page text variable in a template

Display pages by Audience page text variable.

Example:
`>>comment<< [[#byaudience]] (:if ! equal '{=$:Audience}' '{<$:Audience}':) -<'''{=$:Audience}''': (:ifend:) [[{=$Name}]] [[#byaudienceend]] >><< (:pagelist group=PmWiki count=10 fmt=#byaudience order=-$:Audience:)`	{=$:Audience}: {=$Name}? visitors (intermediate) : WebFeeds AccessKeys authors, admins (intermediate) : PageLists authors, admins (advanced) : ConditionalMarkup authors (intermediate) : Uploads PageVariables GroupHeaders IncludeOtherPages TableDirectives Categories

Use page text variables in conditional markup

Page text variables will be assigned/evaluated before any conditional markup is evaluated. This effectively means that you cannot declare a PTV within an if...else condition; and also that a PTV will have a value even if it is set within a (:if false:)....(:if:) condition.

Usage - from within code (developers only)

The standard PageVar($pagename,$varname) function can return page text variables, but remember to include the dollar and colon like this:

$var=PageVar($pagename,'$:City')

It works by caching all page (text) variables it finds in a page (in $PCache) and returns the one requested.