Difference between revisions of "Counters"
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(change "number" to "counter") |
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| Line 4: | Line 4: | ||
<texcode> | <texcode> | ||
| − | \ | + | \setcounter[userpage][1] |
</texcode> | </texcode> | ||
| Line 10: | Line 10: | ||
<texcode> | <texcode> | ||
| − | \ | + | \resetcounter [page] |
| − | \ | + | \incrementcounter[page] |
| − | \ | + | \decrementcounter[page] |
| − | \ | + | \savecounter [page] |
| − | \ | + | \restorecounter [page] |
| − | \ | + | \getcounter [page] |
</texcode> | </texcode> | ||
| Line 23: | Line 23: | ||
<texcode> | <texcode> | ||
| − | \ | + | \definecounter[one] |
| − | \ | + | \definecounter[two][one] |
</texcode> | </texcode> | ||
| Line 30: | Line 30: | ||
<context source="yes"> | <context source="yes"> | ||
| − | \ | + | \definecounter[one] |
| − | \ | + | \definecounter[two][one] |
| − | Default value of counter one: \ | + | Default value of counter one: \getcounter[one] |
We increment counter two | We increment counter two | ||
| − | \ | + | \incrementcounter[two] |
| − | New value of counter one: \ | + | New value of counter one: \getcounter[one] |
</context> | </context> | ||
| − | By default counters are reset with each new chapter. To have a counter which isn’t reset one needs “way=bytext" and to remove the chapter number from the \ | + | By default counters are reset with each new chapter. To have a counter which isn’t reset one needs “way=bytext" and to remove the chapter number from the \getcounter result one has to add “prefix=no”. |
An example definition is | An example definition is | ||
<texcode> | <texcode> | ||
| − | \ | + | \definecounter[examplecounter][way=bytext,prefix=no] |
</texcode> | </texcode> | ||
== Testing the Value of a Counter == | == Testing the Value of a Counter == | ||
| − | If you need to test the value of a counter, use \rawcountervalue, not \ | + | If you need to test the value of a counter, use \rawcountervalue, not \getcounter: |
<texcode> | <texcode> | ||
| − | \ | + | \definecounter[mynumber][] |
| − | \ | + | \setcounter[mynumber][42] |
| − | \doifelse{\ | + | \doifelse{\getcounter[mynumber]}{42}{ |
| − | Strange, \type{\ | + | Strange, \type{\getcounter} worked. |
}{ | }{ | ||
| − | Using \type{\ | + | Using \type{\getcounter} does not work. |
} | } | ||
| Line 69: | Line 69: | ||
== Forcing the Reset of a Counter == | == Forcing the Reset of a Counter == | ||
| − | Due to a current bug[http://www.mail-archive.com/ntg-context%40ntg.nl/msg78847.html], counters are reset by chapter, page, etc. only when they are incremented. | + | Due to a current bug [http://www.mail-archive.com/ntg-context%40ntg.nl/msg78847.html], counters are reset by chapter, page, etc. only when they are incremented. |
To force the reset, you can increment and then decrement a counter before using it. | To force the reset, you can increment and then decrement a counter before using it. | ||
<texcode> | <texcode> | ||
| Line 83: | Line 83: | ||
== \definenumber or \definecounter ? == | == \definenumber or \definecounter ? == | ||
| − | + | {{cmd|definenumber}} etc. are obsolete aliases for {{cmd|definecounter}} etc. | |
== Names of Commonly Used Counters == | == Names of Commonly Used Counters == | ||
| − | * <code>page</code> for pagenumbers | + | * <code>userpage</code> for visible pagenumbers |
| − | * <code>formula</code> for | + | * <code>page</code> for internal pagenumbers |
| − | * <code>table</code> for | + | * <code>formula</code> for formula numbers |
| − | * <code>figure</code> for | + | * <code>table</code> for table numbers |
| + | * <code>figure</code> for figure numbers | ||
[[Category:Programming and Databases]] | [[Category:Programming and Databases]] | ||
[[Category:Tools]] | [[Category:Tools]] | ||
Revision as of 21:50, 28 October 2023
< Main Page | Inside ConTeXt >
ConTeXt provides a higher layer of API to access various counters. For example, to set the page number to a certain value use
\setcounter[userpage][1]
Other useful commands for working with counters are
\resetcounter [page] \incrementcounter[page] \decrementcounter[page] \savecounter [page] \restorecounter [page] \getcounter [page]
Contents
Coupling Counters
Two counters can be coupled by
\definecounter[one] \definecounter[two][one]
For example
\definecounter[one] \definecounter[two][one] Default value of counter one: \getcounter[one] We increment counter two \incrementcounter[two] New value of counter one: \getcounter[one]
By default counters are reset with each new chapter. To have a counter which isn’t reset one needs “way=bytext" and to remove the chapter number from the \getcounter result one has to add “prefix=no”.
An example definition is
\definecounter[examplecounter][way=bytext,prefix=no]
Testing the Value of a Counter
If you need to test the value of a counter, use \rawcountervalue, not \getcounter:
\definecounter[mynumber][] \setcounter[mynumber][42] \doifelse{\getcounter[mynumber]}{42}{ Strange, \type{\getcounter} worked. }{ Using \type{\getcounter} does not work. } \doifelse{\rawcountervalue[mynumber]}{42}{ Ok, the test with \type{\rawcountervalue} worked. }{ Strange, \type{\rawcountervalue} failed. }
Forcing the Reset of a Counter
Due to a current bug [1], counters are reset by chapter, page, etc. only when they are incremented. To force the reset, you can increment and then decrement a counter before using it.
\definecounter[mycounter][way=bypage] \setcounter[mycounter][10] \rawcountervalue[mycounter] \page % new page, mycounter should be reset \rawcountervalue[mycounter] % no, it's not reset: you still get '10' \incrementcounter[mycounter]\decrementcounter[mycounter] \rawcountervalue[mycounter] % now you should get '0' because it has been reset
\definenumber or \definecounter ?
\definenumber etc. are obsolete aliases for \definecounter etc.
Names of Commonly Used Counters
userpagefor visible pagenumberspagefor internal pagenumbersformulafor formula numberstablefor table numbersfigurefor figure numbers
