[Haskell-cafe] Problem compiling a CGI script that needs to write
to file during its execution
jefferson.r.heard at gmail.com
Tue Jul 29 12:14:52 EDT 2008
Beautiful, thank you. That worked.
On Tue, Jul 29, 2008 at 12:07 PM, allan <a.d.clark at ed.ac.uk> wrote:
> I had this same problem and I'm not sure my way is correct but I used 'Control.Monad.Trans.liftIO'
> Here is some code that I am using
> The main program is pretty simple we just run the CGI action.
> main :: IO ()
> main = Cgi.runCGI $ Cgi.handleErrors cgiMain
> To be able to produce graphs which we can then display in the output
> webpage we require that our main function, that is the one which creates
> the page be in the IO monad.
> cgiMain :: CGI CGIResult
> cgiMain =
> do visitInfo <- getAnalysisData
> page <- Monad.Trans.liftIO $ createPage visitInfo
> Cgi.output $ Xhtml.renderHtml page
> createPage :: Visit -> IO Html
> createPage ..... blah stuff you don't care about
> getAnalysisData :: CGI Visit
> Visit is a data type I've made to hold the information obtained from the page.
> Hope this helps
> Jefferson Heard wrote:
>> Please ignore the obvious security holes, as this is not a script
>> meant for public consumption, but some internal testing and
>> prototyping. I would like to write the result of my computation out
>> to a file inside of cgiMain, but the type of the monad inside cgiMain
>> is this odd CGIT IO CGIResult. I tried using liftM on writeFile, but
>> it then complained that "newanns" was a string instead of a list of
>> strings, which I don't understand at all. Here's the code:
> [snip code]
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