Antiblavers | PmWiki / ConditionalMarkup

authors, admins (advanced)

Using the (:if:) Directive

The (:if:) directive allows portions of a page to be included or excluded from processing. The generic form of the (:if:) directive is

(:if cond param:) body (:ifend:)

where "cond" names a condition to be tested (described below), and "param" is a parameter or other argument to the condition.

The built-in conditions include:

`(:if name PAGENAME:)`	-	current page is named "`PAGENAME`"
`(:if group GROUPNAME:)`	-	current group is named "`GROUPNAME`"
`(:if auth LEVEL PAGENAME:)`	-	viewer is authorized at "`LEVEL`" where `LEVEL` can be: `read`, `edit`, `upload`, `attr` or `admin`; `PAGENAME` is optional.
`(:if authid:)`	-	current viewer is authenticated
`(:if true:)`	-	always include text
`(:if false:)`	-	always exclude text (same as a comment)
`(:if attachments:)`	-	current page has attachments
`(:if date DATE:)`	-	true if current date is `DATE`
`(:if date DATE..:)`	-	true if current date is `DATE` or later (unlimited)
`(:if date DATE1..DATE2:)`	-	true if current date is in range `DATE1` to `DATE2` (inclusive)
dates are in the format yyyy-mm-dd or yyyymmdd
`(:if enabled VAR:)`	-	true if PHP VAR is true
`(:if enabled AuthPw:)`	-	true if user has entered any password during the current browser session.
`(:if equal STRING1 STRING2:)`	-	true if `STRING1` equals `STRING2`
`(:if match REG_EXPRESSION:)`	-	true if current page name matches the regular expression
`(:if exists PAGENAME:)`	-	true if the page pagename exists

Negated forms of conditions also work:

`(:if !attachments:)`	-	this page has no attachments

`(:if ! name PAGENAME:)`		current page is NOT named "`PAGENAME`"
`(:if name -PAGENAME :)`
`(:if name !PAGENAME :)`

Any (:if:) automatically terminates the previous one, thus markup can be easily cased (and are not nested):

(:if enabled AuthPw:)* You're logged in
(:if auth read:)* You can read
(:if auth edit:)* You can edit
(:if auth upload:)* You can upload
(:ifend:)

Using wildcard placeholders

The character * can be used as a wildcard to represent any character, zero, one or multiple times.
The character ? can be used as a wildcard to represent any character exactly one time.
Wildcard characters (* and ?) can be used in conditional markup, thus:

`(:if name PmCal.2005* :)`	-	current page is in group PmCal and begins with 2005
`(:if group PmWiki* :)`	-	current page is in group PmWiki or a group beginning with Pmwiki
`(:if name Profiles.*,-Profiles.Profiles :)`	-	current page is in group `Profiles` but not `Profiles.Profiles`

Combining conditions

Conditions (as previously defined) may be combined into more complex conditional expressions using one of these three equivalent forms:

(:if expr EXPRESSION :)
(:if [ EXPRESSION ] :)
(:if ( EXPRESSION ) :)

Conditions are combined into expressions with boolean operators and brackets. In the next table, A and B are either regular conditions or bracketed sub-expressions of regular conditions:

Expression	Operator	Result
`A and B`	And	TRUE if both A and B are TRUE.
`A or B`	Or	TRUE if either A or B is TRUE.
`A xor B`	Xor	TRUE if either A or B is TRUE, but not both.
`! A`	Not	TRUE if A is not TRUE.
`A && B`	And	TRUE if both A and B are TRUE.
`A \|\| B`	Or	TRUE if either A or B is TRUE.

Nota:

Spaces around operators and brackets are required.
No specific feedback is given for syntaxic errors or unbalanced brackets.

Thus, writing:

(:if expr auth admin || auth attr || auth edit :)
[[Logout -> {$Name}?action=logout]]
(:if:)

provides you a logout link only when authentified with rights higher than 'read'.

admins (advanced)

Creating new conditions

See Cookbook:ConditionalMarkupSamples.

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