<!--roptions dev="png", fig.width=5, fig.height=5, fig.path='ex-out-', tidy=TRUE-->

One of the great things about knitr is its flexibility.  Here I set knitr up to publish to Wordpress.
I will then use RWordPress to publish the output automatically.   

I will base the wordpress format on the github-flavored markdown format.  I change the markup for output and source-code to use the nice codeblocks provided by the syntax highlighter plugin.  I also specify that images should use the html markup instead of github markup, and I will take advantage of knitr support for imgur to upload and host the image files automatically.   


<!--begin.rcode setup
render_gfm() 
options(width=30)
opts_knit$set(upload = TRUE)
knit_hooks$set(output = function(x, options) paste("[code]\n", x, "[/code]\n", sep = ""),
              source = function(x, options) paste("[code lang='r']\n", x, "[/code]\n", sep = ""),
              plot = hook_plot_html) 
end.rcode-->

Now we write some code chunks in this markdown file:

<!--begin.rcode
## a simple calculator
  1+1
## boring random numbers
  set.seed(123)
  rnorm(5)
end.rcode-->

We can also produce plots which are uploaded to imgur.com:

<!--begin.rcode md-cars, message=FALSE
  library(ggplot2)
  qplot(hp, mpg, data=mtcars)+geom_smooth()
  ggpcp(mtcars) + geom_line()
end.rcode-->


We can then post the result using RWordPress:

<!--begin.rcode rwordpress, eval=FALSE
require(RWordPress)
text = paste(readLines('wordpress.md'), collapse = '\n')
title = 'Using knitr and RWordPress to publish results directly from R'
newPost(list(description = text, title = title), publish = FALSE)
end.rcode-->

Above we specify publish = FALSE which will make the post upload as a draft where we can preview it.  To publish directly we could omit that command.  Giving a title is intuitive. Note that we have to read the text in and substitue newline characters for line-breaks.   

Note that this requires setting the login options securely in .Rprofile, for example:
<!--begin.rcode options, eval=FALSE
options(WordpressLogin = c(userid = "password"), WordpressURL = "http://www.yourdomain.com/xmlrpc.php")
end.rcode-->


It would be nice to use the uploadFile function from RWordPress to host the images, but that seems to be giving me trouble at the moment.