Difference between revisions of "Counters"
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== \definenumber or \definecounter ? == | == \definenumber or \definecounter ? == | ||
− | In ConTeXt MkIV {{cmd | + | In ConTeXt MkIV {{cmd|definecounter}}, {{cmd|incrementcounter}}, etc. seem to be preferred to {{cmd|definenumber}}, {{cmd|incrementnumber}}, etc. |
== Names of Commonly Used Counters == | == Names of Commonly Used Counters == |
Revision as of 13:41, 22 February 2016
< 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
\setnumber[page][1]
Other useful commands for working with counters are
\resetnumber [page] \incrementnumber[page] \decrementnumber[page] \savenumber [page] \restorenumber [page] \getnumber [page]
Contents
Coupling Counters
Two counters can be coupled by
\definenumber[one] \definenumber[two][one]
For example
\definenumber[one] \definenumber[two][one] Default value of counter one: \getnumber[one] We increment counter two \incrementnumber[two] New value of counter one: \getnumber[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 \getnumber result one has to add “prefix=no”.
An example definition is
\definenumber[examplecounter][way=bytext,prefix=no]
Testing the Value of a Counter
If you need to test the value of a counter, use \rawcountervalue, not \getnumber:
\definenumber[mynumber][] \setnumber[mynumber][42] \doifelse{\getnumber[mynumber]}{42}{ Strange, \type{\getnumber} worked. }{ Using \type{\getnumber} 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 ?
In ConTeXt MkIV \definecounter, \incrementcounter, etc. seem to be preferred to \definenumber, \incrementnumber, etc.
Names of Commonly Used Counters
page
for pagenumbersformula
for formulanumberstable
for tablesfigure
for figures