--- loncom/cgi/graph.png 2003/01/13 17:41:45 1.20 +++ loncom/cgi/graph.png 2005/04/07 06:56:21 1.34 @@ -1,6 +1,6 @@ #!/usr/bin/perl # -# $Id: graph.png,v 1.20 2003/01/13 17:41:45 minaeibi Exp $ +# $Id: graph.png,v 1.34 2005/04/07 06:56:21 albertel Exp $ # # Copyright Michigan State University Board of Trustees # @@ -25,96 +25,219 @@ # http://www.lon-capa.org/ # # The LearningOnline Network with CAPA -# Behrouz Minaei -# YEAR=2001 -# 9/13/01, 9/25/01, 10/6/01, 10/9/01, 12/25/01 -# YEAR=2002 -# 2/1/, 5/13, 5/15 -# YEAR=2003 -# 1/7/, 1/13 +# # A CGI script that dynamically outputs a graphical chart for lonstatistics. # #### +=pod + +=head1 NAME + +graph.png + +=head1 SYNOPSIS + +produces plots from data stored in users environment. + +=head1 DESCRIPTION + +graph.png is a cgi-bin script which produces plots based on data stored +in the users environment. The users cookie is checked prior to producing +a plot. The query string is expected to be an identifier, $id. +The parameters defining the plot must be stored in the environment as +$ENV{'cgi.'.$id.'.'.$dataname}. Two types of plots can be produced, 'bar' +and 'xy'. The 'xy' graph can will 1 or 2 y-axes if the parameter +'two_axes' is set to false or true respectively. See perldoc GD::Graph and +loncommon::DrawBarGraph, loncommon::DrawXYGraph, and loncommon::DrawXYYGraph. + +=cut + use strict; +use lib '/home/httpd/lib/perl'; use GD::Graph::bars; +use GD::Graph::lines; use GD::Graph::colour; use GD::Graph::Data; +use LONCAPA::loncgi; + +sub unescape { + my $str=shift; + $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg; + return $str; +} + +sub error { + my ($error) = @_; + my $Str = <<"END"; +Content-type: text/html + + +
+There was an error producing the graph you requested. +
+$error +
+ + +END + return $Str; +} + +my $id = $ENV{'QUERY_STRING'}; + +# +# usage: &get_env($name,$default) +sub get_env { + my $key = 'cgi.'.$id.'.'.(shift()); + return shift if (! exists($env{$key})); + return $env{$key}; +} + +if (! &LONCAPA::loncgi::check_cookie_and_load_env()) { + print <