FlexRTHTML.Rmd

---
title: "Create WiniWeb SL HTML page"
output: html_notebook
---

```{r}
# name if input FWX configuration file
fwx.name <- "G:/Documents and Settings/WinXP/My Documents/simatic/PDATA.fwx"
# name of output HTML page
fwx.html <- "G:/Documents and Settings/WinXP/My Documents/simatic/tags.html"

library(knitr)
source(purl('FlexRT.rmd', output = tempfile()))
```
Create HTML page with MiniWeb Server Language (MWSL) to view the values of all variables

**TODO:**

- [ ] support tags with data_len = 0 - they probably have more meta info
- [ ] split HTML file into smaller parts, because MiniWeb has a size limit

```{r}
# load a file and replace strings with magic words $1$, $2$,...
load_replace <- function(file_name, reps) {
  handle <- file(file_name)
  text <- readLines(handle)
  close(handle)
  
  counter=1
  for(magicword in reps) {
    if (is.na(magicword)) {
      magicword <- ''
    }
    magicnumber <- paste('$',counter,'$',sep='')
    text <- gsub(magicnumber, magicword, text, fixed = T)
    counter <- counter+1
  }
  
  return(text)
}

# check if HTTP is enabled in the FWX
is_weblink <- 'WEBLINK' %in% toc.entries$name
is_startproc <- 'FUNC_STARTPROC' %in% toc.entries$name
is_http <- 'none'
if (is_weblink && is_startproc) {
  is_http <- 'both'
} else if (is_weblink || is_startproc) {
  is_http <- 'at least one'
}

# read template HTML header and replaces all magic words
html_header <- load_replace('html_header.html', c(tags$entries, tags.entries[1,'name'], is_http, is_weblink, is_startproc))
# creates an html file
html.handle<-file(fwx.html,'w')
# write header of HTML page
cat(html_header, sep = '\n',file=html.handle)

# Create an HTML table with a single line for each variable
#   and creates a single line for each element in an array
sorted_tags_idx <- sort(tags.entries$name, index.return=T)$ix
for(i in 1:(tags$entries)) {
  # get current entry
  entry <- tags.entries[sorted_tags_idx[i],]
  arr_size <- entry$array_size
  if (is.na(arr_size)) {
    arr_size <- 1
  }
  # print a line for every item in the array
  type <- type2info(entry$data_type)
  # extract datalink info
  datalink <- dl.entries[dl.entries$idx == entry$idx,]
  # if couldn't extract type code, then get it from the datalink
  if (type$code == 0) {
    type <- type2info(datalink$data_type, TRUE)
    type_name <- type$datalink_name
  } else {
    type_name <- type$name
  }
  for (j in 1:(arr_size)) {
    name_with_index <- entry$name
    type_with_size <- type_name
    if (arr_size > 1) {
      array.index <- paste('[',j-1,']',sep='')
      array.size <- paste('[',arr_size,']',sep='')
      
      name_with_index <- paste(entry$name,array.index,sep='')
      type_with_size <- paste(type_name,array.size,sep='')
    }
    # extract io acquisition time
    acq <- datalink$acq

    # create a table raw with MWSL command to read tag value
    tr <- load_replace('html_table.html', c(datalink$address, name_with_index, type_with_size, name_with_index, type$min, type$max, acq))

    # needs useBytes in order to write UTF-8 characters like ü instead of <U+00FC>
    writeLines(tr, con=html.handle, sep='\n', useBytes = TRUE)
  }
}
# write footer of HTML page
html_footer <- load_replace('html_footer.html', c())
cat(html_footer, sep = '\n',file=html.handle)
# close the html file
close(html.handle)
```