Help on Preferences
Set statements which occur at higher-numbered locations override settings of the same name at lower numbered levels, unless the macro was listed in a FINALPREFERENCES setting (finalised) at a lower-numbered level. In this case, the macro is locked to the value at that level;
Set statements at higher-numbered levels are ignored.
If you are setting a preference and using it in the same topic, note that Foswiki reads all the preference settings
from the saved version of the topic before it displays anything. This means you can use a macro anywhere in the topic, even if you set it somewhere inconspicuous near the end. But beware:
it also means that if you change the setting of a macro you are using in the same topic,
will show the wrong thing, and you must
the topic to see it correctly.
Also note that Foswiki always reads the setting from the most current topic revision, so viewing older revisions of a topic can show unexpected results.
The syntax for setting macros is the same anywhere:
[multiple of 3 spaces] * [space] Set [space] MACRONAME [space] = [space] value
* Set MACRONAME = value
* Set MACRONAME = value
Spaces between the = sign and the value will be ignored. You can split a value over several lines by indenting following lines with spaces - as long as you don't try to use * as the first character on the following line.
* Set MACRONAME = value starts here
and continues here
Whatever you include in your Macro will be expanded on display, exactly as if it had been entered directly.
Example: Create a custom logo macro
* Set MYLOGO = %PUBURL%/%WEB%/LogoTopic/mylogo.gif
You can also set preference settings
in a topic by clicking the link
Edit topic preference settings
More topic actions
. Preferences set in this manner are known as 'meta' preferences and are not visible in the topic text, but take effect nevertheless.
Access Control Settings
These are special types of preference settings to control access to content. AccessControl
explains these security settings in detail.
Local values for preferences
Certain topics (user, plugin, web, site and default preferences topics) have a problem; macros defined in those topics can have two meanings. For example, consider a user topic. A user may want to use a double-height edit box when they are editing their home topic - but only
when editing their home topic. The rest of the time, they want to have a normal edit box. This separation is achieved using
in place of
in the macro definition. For example, if the user sets the following in their home topic:
* Set EDITBOXHEIGHT = 10
* Local EDITBOXHEIGHT = 20
Then, when they are editing any other topic, they will get a 10 high edit box. However, when they are editing their home topic they will get a 20 high edit box.
can be used wherever a preference needs to take a different value depending on where the current operation is being performed.
Use this powerful feature with great care!
can be used to get a listing of the values of all macros in their evaluation order, so you can see macro scope if you get confused.