IF Statements

The %IF% construct gives TWiki the power to include content in topics based on the value of simple expressions.

Line: 9 to 9

Note that because of the way TWiki evaluates, then whatever is in the THEN and ELSE parameters will already have been expanded by the time the condition is actually evaluated. The standard FormatTokens can be used in the THEN and ELSE parameters when you need to delay evaluation of (for example) a TWiki variable.

Changed:

<
< The basic syntax of a condition is the same as the syntax used for queries, with the addition of the following special operators:

>
> The basic syntax of a condition is the same as the syntax used for queries, with operators =, !=, ~, <, >, <=, >=, NOT, AND, OR, (), and functions lc(), uc(), d2n(). In addition, the following special operators are supported:

Changed:

<
<

context	True if the current context is set (see below)
allows	`'X' allows 'Y'` is true if web/topic 'X' exists and allows access mode 'Y' for the current user. Web access rights are only checked if there is no topic called 'X'.
istopic	`istopic 'X'` is true if topic 'X' exists
isweb	`isweb 'X'` is true if web 'X' exists
ingroup	`'X' ingroup 'Y'` is true if user 'X' is in group 'Y'. 'X' can be a login name or a wikiname.
defined	True if a preference variable or url parameter of this name is defined.
$	expands a URL parameter or TWikiVariable name. Plugin handlers are not called. Built-in variables and user-defined preferences are supported. You can pass a limited subset of parameters to TWiki variables by enclosing the variable name in single quotes; for example, `$ 'VARIABLE{value}'`. The `'VARIABLE{value}'` string may not contain quotes (' or ").
{X}	expands to the value of the configuration variable {X} - for example, `{ScriptUrlPath}`

>
>

`context`	True if the current context is set (see below)
`allows`	`'X' allows 'Y'` is true if web/topic 'X' exists and allows access mode 'Y' for the current user. Web access rights are only checked if there is no topic called 'X'.
`istopic`	`istopic 'X'` is true if topic 'X' exists
`isweb`	`isweb 'X'` is true if web 'X' exists
`ingroup`	`'X' ingroup 'Y'` is true if user 'X' is in group 'Y'. 'X' can be a login name or a wikiname.
`defined`	True if a preference variable or url parameter of this name is defined.
`$`	expands a URL parameter or TWikiVariable name. Plugin handlers are not called. Built-in variables and user-defined preferences are supported. You can pass a limited subset of parameters to TWiki variables by enclosing the variable name in single quotes; for example, `$ 'VARIABLE{value}'`. The `'VARIABLE{value}'` string may not contain quotes (' or ").
`{X}`	expands to the value of the configuration variable {X} - for example, `{ScriptUrlPath}`

Examples:

Line: 91 to 91

Context identifiers are used in TWiki to label various stages of the rendering process. They are especially useful for skin authors to find out where they are in the rendering process. The following context identifiers are available:

id	context

Changed:

<
<

absolute_urls	Set if absolute URLs are required
attach	in attach script (see TWikiScripts)
authenticated	a user is authenticated
body_text	when the body text is being processed in a view (useful in plugin handlers)
can_login	current environment supports login
changes	in changes script (see TWikiScripts)
command_line	the running script was run from the command line, and not from CGI
diff	in rdiff script (see TWikiScripts)
edit	in edit script (see TWikiScripts)
footer_text	when the footer text is being processed in a view (useful in plugin handlers)
header_text	when the header text is being processed in a view (useful in plugin handlers)
i18n_enabled	when user interface I18N support is enabled (i.e., user can choose the language for UI)
inactive	if active links such as 'edit' and 'attach' should be disabled
login & logon	in login / logon script (see TWikiScripts)
manage	in manage script (see TWikiScripts)
mirror	if this is a mirror
new_topic	if the topic doesn't already exist
oops	in oops script (see TWikiScripts)
preview	in preview script (see TWikiScripts)
register	in register script (see TWikiScripts)
rename	in rename script (see TWikiScripts)
resetpasswd	in resetpasswd script (see TWikiScripts)
rss	if this is an RSS skin rendering
save	in save script (see TWikiScripts)
search	in search script (see TWikiScripts)
statistics	in statistics script (see TWikiScripts)
textareas_hijacked	provided for use by editors that highjack textareas, and want to signal this fact. This is used by skins, for example, so they can suppress extra controls when textareas have been hijacked.
upload	in upload script (see TWikiScripts)
view	in view script (see TWikiScripts)
viewfile	in viewfile script (see TWikiScripts)
rest	in rest script (see TWikiScripts)
registration_supported	registration is supported by the current UserMapper
registration_enabled	set if `{Register}{EnableNewUserRegistration}` is on, and registrationis supported
passwords_modifyable	set if the password manager support changing the password / email

>
>

`absolute_urls`	Set if absolute URLs are required
`attach`	in attach script (see TWikiScripts)
`authenticated`	a user is authenticated
`body_text`	when the body text is being processed in a view (useful in plugin handlers)
`can_login`	current environment supports login
`changes`	in changes script (see TWikiScripts)
`command_line`	the running script was run from the command line, and not from CGI
`diff`	in rdiff script (see TWikiScripts)
`edit`	in edit script (see TWikiScripts)
`footer_text`	when the footer text is being processed in a view (useful in plugin handlers)
`header_text`	when the header text is being processed in a view (useful in plugin handlers)
`i18n_enabled`	when user interface I18N support is enabled (i.e., user can choose the language for UI)
`inactive`	if active links such as 'edit' and 'attach' should be disabled
`login` & `logon`	in login / logon script (see TWikiScripts)
`manage`	in manage script (see TWikiScripts)
`mirror`	if this is a mirror
`new_topic`	if the topic doesn't already exist
`oops`	in oops script (see TWikiScripts)
`preview`	in preview script (see TWikiScripts)
`register`	in register script (see TWikiScripts)
`rename`	in rename script (see TWikiScripts)
`resetpasswd`	in resetpasswd script (see TWikiScripts)
`rss`	if this is an RSS skin rendering
`save`	in save script (see TWikiScripts)
`search`	in search script (see TWikiScripts)
`statistics`	in statistics script (see TWikiScripts)
`textareas_hijacked`	provided for use by editors that highjack textareas, and want to signal this fact. This is used by skins, for example, so they can suppress extra controls when textareas have been hijacked.
`upload`	in upload script (see TWikiScripts)
`view`	in view script (see TWikiScripts)
`viewfile`	in viewfile script (see TWikiScripts)
`rest`	in rest script (see TWikiScripts)
`registration_supported`	registration is supported by the current UserMapper
`registration_enabled`	set if `{Register}{EnableNewUserRegistration}` is on, and registrationis supported
`passwords_modifyable`	set if the password manager support changing the password / email

In addition there is a context identifier for each enabled plugin; for example, if GallousBreeksPlugin is installed and enabled, then the context ID GallousBreeksPluginEnabled will be set. Other extensions may set additional context identifiers.

View | History: r12 < r11 < r10 < r9 | More

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