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107 lines
2.2 KiB
R
107 lines
2.2 KiB
R
\name{renderText}
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\alias{renderText}
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\title{Text Output}
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\usage{
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renderText(expr, env = parent.frame(), quoted = FALSE,
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func = NULL)
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}
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\arguments{
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\item{expr}{An expression that returns an R object that
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can be used as an argument to \code{cat}.}
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\item{env}{The environment in which to evaluate
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\code{expr}.}
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\item{quoted}{Is \code{expr} a quoted expression (with
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\code{quote()})? This is useful if you want to save an
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expression in a variable.}
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\item{func}{A function that returns an R object that can
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be used as an argument to \code{cat}.(deprecated; use
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\code{expr} instead).}
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}
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\description{
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Makes a reactive version of the given function that also
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uses \code{\link[base]{cat}} to turn its result into a
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single-element character vector.
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}
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\details{
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The corresponding HTML output tag can be anything (though
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\code{pre} is recommended if you need a monospace font
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and whitespace preserved) and should have the CSS class
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name \code{shiny-text-output}.
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The result of executing \code{func} will passed to
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\code{cat}, inside a \code{\link[utils]{capture.output}}
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call.
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}
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\examples{
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isolate({
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# renderPrint captures any print output, converts it to a string, and
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# returns it
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visFun <- renderPrint({ "foo" })
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visFun()
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# '[1] "foo"'
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invisFun <- renderPrint({ invisible("foo") })
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invisFun()
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# ''
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multiprintFun <- renderPrint({
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print("foo");
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"bar"
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})
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multiprintFun()
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# '[1] "foo"\\n[1] "bar"'
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nullFun <- renderPrint({ NULL })
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nullFun()
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# 'NULL'
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invisNullFun <- renderPrint({ invisible(NULL) })
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invisNullFun()
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# ''
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vecFun <- renderPrint({ 1:5 })
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vecFun()
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# '[1] 1 2 3 4 5'
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# Contrast with renderText, which takes the value returned from the function
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# and uses cat() to convert it to a string
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visFun <- renderText({ "foo" })
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visFun()
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# 'foo'
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invisFun <- renderText({ invisible("foo") })
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invisFun()
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# 'foo'
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multiprintFun <- renderText({
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print("foo");
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"bar"
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})
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multiprintFun()
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# 'bar'
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nullFun <- renderText({ NULL })
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nullFun()
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# ''
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invisNullFun <- renderText({ invisible(NULL) })
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invisNullFun()
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# ''
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vecFun <- renderText({ 1:5 })
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vecFun()
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# '1 2 3 4 5'
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})
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}
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\seealso{
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\code{\link{renderPrint}} for capturing the print output
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of a function, rather than the returned text value.
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}
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