add content Type and Disposition

[ycphs]

reprex::reprex({
  library(plumber)
library(openxlsx)
#* @serializer contentTypeDisposition list(type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",disposition='attachment; filename="tmp.xlsx"')

#* @get /xlsx
function(){
   tmp <- tempfile(fileext = ".xlsx")
  data.frame(a=1:10,b=11:20)
write.xlsx(erg,tmp,withFilter=T)
  
  readBin(tmp, "raw", n=file.info(tmp)$size)
}
})

The serializer contentType returned named files without extension.

 library(plumber)
library(openxlsx)
#* @serializer contentType list(type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")

#* @get /xlsx
function(){
   tmp <- tempfile(fileext = ".xlsx")
  data.frame(a=1:10,b=11:20)
write.xlsx(erg,tmp,withFilter=T)
  
  readBin(tmp, "raw", n=file.info(tmp)$size)
}

[CLAassistant]

All committers have signed the CLA.

[ycphs]

corrected documentation

[codecov-io]

Codecov Report

Merging #455 into master will increase coverage by 0.13%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #455      +/-   ##
==========================================
+ Coverage   89.84%   89.98%   +0.13%     
==========================================
  Files          29       29              
  Lines        1527     1537      +10     
==========================================
+ Hits         1372     1383      +11     
+ Misses        155      154       -1

Impacted Files	Coverage Δ
R/serializer-content-type.R	95.23% <100%> (+4.32%)	⬆️
R/response.R	100% <0%> (ø)	⬆️
R/cookie-parser.R	100% <0%> (+6.25%)	⬆️

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[schloerke]

@ycphs Thank you for the PR and tests!

With content disposition being tied to content type, how do you feel about making content_type serializer better vs making a new method?

# untested
serializer_content_type <- function(type, disposition = NULL, filename = NULL) {
  if (missing(type)) {
    stop("You must provide the custom content type to the serializer_content_type_disposition")
  }

  # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Disposition
  if (!is.null(disposition)) {
    disposition <- match.arg(disposition, c("inline", "attachment"))
    if (disposition == "attachment" && !is.null(filename)) {
      filename <- as.character(filename)
      if (grepl("\"", filename, fixed = TRUE)) {
        stop("quotes can not be used in the value of `filename`")
      }
      disposition <- paste0(disposition, "; filename=\"", filename, "\"")
    }
  }

  function(val, req, res, errorHandler) {
    tryCatch({
      res$setHeader("Content-Type", type)
      if (!is.null(disposition)) {
        res$setHeader("Content-Disposition", disposition)
      }
      res$body <- val

      return(res$toResponse())
    }, error=function(e) {
      errorHandler(req, res, e)
    })
  }
}

[ycphs]

@schloerke: Yes for me that's also good.

Do you change it yourself or should I change it?

[ycphs]

@schloerke I updated the method and tests.

[ycphs]

change according of appveyor.yml to: Provide more advice re: env vars #147

[cpsievert]

@schloerke

• consider generalizing this so that other exported serializers can take advantage

• consider adding a withHeaders serializer