R/svgviewr.write.R

In svgViewR: 3D Animated Interactive Visualizations Using SVG and WebGL

svgviewr.write <- function(new_lines, save_as_fpath, append=FALSE){

	# Input is file path
	if(class(save_as_fpath)[1] == 'character'){

		# IF FILE DOES NOT EXIST MAKE NEW FILE
		if(!file.exists(save_as_fpath)){write(new_lines, save_as_fpath);return(1)}

		# READ EXISTING FILE
		fileConn <- file(save_as_fpath)
		readLines.result <- readLines(fileConn)
		close(fileConn)

		if(append){
	
			# FIND LINE CONTAINING SVG_DOC TAG
			n_add <- grep('</svg_doc>', readLines.result)
		
			# COMBINE CURRENT AND NEW LINES
			new_lines <- c(readLines.result[1:(n_add-1)], new_lines, readLines.result[(n_add):length(readLines.result)])
		}else{
			# FIND LINES AT BEGINNING AND END OF SVG_DOC BLOCK
			n_start <- grep('<svg_doc xmlns=\"http://www.w3.org/2000/svg\" version=\"1.1\" style=\"visibility:hidden;\" >', readLines.result)
			n_end <- grep('</svg_doc>', readLines.result)

			# COMBINE CURRENT AND NEW LINES
			new_lines <- c(readLines.result[1:(n_start)], new_lines, readLines.result[(n_end):length(readLines.result)])
		}

		# WRITE IN NEW LINES
		fileConn <- file(save_as_fpath)
		write(new_lines, fileConn)
		close(fileConn)

	}else{

		# Write lines to connection
		write(new_lines, save_as_fpath$con)
	}
	
	NULL
}