--- loncom/cgi/graph.png 2003/10/09 22:04:37 1.24 +++ loncom/cgi/graph.png 2004/01/08 15:50:17 1.33 @@ -1,6 +1,6 @@ #!/usr/bin/perl # -# $Id: graph.png,v 1.24 2003/10/09 22:04:37 matthew Exp $ +# $Id: graph.png,v 1.33 2004/01/08 15:50:17 matthew Exp $ # # Copyright Michigan State University Board of Trustees # @@ -38,25 +38,25 @@ graph.png =head1 SYNOPSIS -produces plots based on input +produces plots from data stored in users environment. =head1 DESCRIPTION -graph.png is a cgi-bin script which produces plots based on input data. - -The query string is expected to be as follows (without whitespace): - -escape(Plot title) & escape(X label)& escape(Y label) & Maximum Y value & -Number of bars & $data1 & $data2 - -$data1 and $data2 are expected to be comma seperated lists of numbers. -escape( value ) means the values must be run through lonnet::escape. +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(); @@ -67,6 +67,35 @@ sub unescape { 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 <