HTMLtools {CGIwithR} | R Documentation |
These functions provide shorthand ways of sending simple HTML constructions to standard output.
HTMLheader(title = character(0), css = character(0)) tag(tagname, ...) untag(tagname) comments(text) br(n = 1) linkto(text, URL) mailto(text, address) img(src, ..., graphURLroot) lf(n = 1)
tagname |
an HTML tag identifier, such as PRE ,
BODY , B , etc. If
getOption("useUnquotedTagnames")
is TRUE (the default, which can be unset by
options(useUnquotedTagnames = FALSE) ),
tag names do not need to be
quoted, for example tag(PRE) can be used in place
of tag("PRE") . Otherwise tagname
should be a character string. |
... |
HTML qualifier(s) such as color="red" |
text |
a character string |
URL |
the target URL for an HTML anchor |
address |
the email address in a mailto: construction |
n |
an integer number of linefeeds or <BR>s to insert in the output |
src |
a character string, the URL for the image |
graphURLroot |
a character string giving the name of the directory in the Web site to in which the image file is located. This is not the actual directory in the file system, but rather the name of the directory as seen by a Web client. |
title |
a character vector whose contents are collapsed into a single string (separated by spaces) and inserted into an HTML title |
css |
a character vector giving the file names or URIs of the Cascading Style
Sheet files to load for the HTML document.
For each element, a
<LINK rel="stylesheet" type="text/css" HREF=...>
is inserted into the HEAD element of the HTML document.
For elements that have a name, the name is treated as the
value of the MEDIA attribute and added to the LINK element.
|
These functions are all shorthand wrappers for commonly-used HTML
constructions. Each simply outputs a piece of HTML code. Any of
these can be done manually instead (using cat
, for example)
if something nonstandard is required.
HTMLheader()
writes out the DOCTYPE, HTML, HEAD and start of
the BODY element in the document. If title
or css
are specified in the call, then the corresponding elements are added
to the HEAD element.
HTMLfooter
closes the BODY and HTML tags at the end of the document.
tag
and untag
supply field signifiers such as
<BODY>
and </BODY>
.
comments
puts text inside the HTML comment markers
<!--
and -->
.
br
outputs a <BR>
(or more than one if n
is
greater than 1).
lf(n)
inserts n
linefeeds into the output.
linkto, mailto, img
provide the standard HTML anchor, email
and image insertion. For img
, note that the source URL
src
is defined relative to graphURLroot
if that
is defined. For example, if graphURLroot
is
"/home/david/graphs/"
then img("mypic.png")
will output
<IMG SRC="/home/david/graphs/mypic.png">
. (Actually, a
random query string is added to the URL by img
to ensure that browsers do not display old, cached
versions of graphs.)
None (invisible(NULL)
), except for img
which returns
invisible("image")
David Firth d.firth@warwick.ac.uk
useUnquotedTagnames <- TRUE testpage<-function(){ tag(HTML) tag(HEAD) tag(TITLE) cat("An example HTML page") untag(TITLE) untag(HEAD) lf() comments("Some comments to be ignored by the web browser") lf(2) tag(BODY, bgcolor = "yellow") lf(2) tag(h1) cat("A large heading") untag(h1) lf(2) tag(p) cat("A table of results:") tag(pre) lf() indentPrint(data.frame(Est = c(1.23,3.45), StErr = c(0.86,0.78), row.names = c("b0","b1"))) lf() untag(pre) untag(p) lf(2) cat("Here is a graph:") ; br() img(src="http://www.stats.ox.ac.uk/~firth/CGIwithR/test.png") ; br(2) lf(2) cat("The author is ") mailto("David Firth", "david.firth@nuffield.ox.ac.uk") cat(" and here is his ") linkto("website.", "http://www.stats.ox.ac.uk/~firth/") ; br() lf() tag(p) cat("Output produced at ", date()) untag(p) lf() untag(BODY) lf() untag(HTML) lf() } # sink("temp.html") testpage() ## The output if pasted into a file should be viewable by ## a web browser. Or if the this-is-escaped-codenormal-bracket83bracket-normal was done, ## just view temp.html in the web browser.