--- loncom/xml/lonplot.pm	2001/12/27 19:47:02	1.19
+++ loncom/xml/lonplot.pm	2001/12/31 17:30:09	1.27
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # Dynamic plot
 #
-# $Id: lonplot.pm,v 1.19 2001/12/27 19:47:02 matthew Exp $
+# $Id: lonplot.pm,v 1.27 2001/12/31 17:30:09 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -26,13 +26,14 @@
 # http://www.lon-capa.org/
 #
 # 12/15/01 Matthew
-# 12/17 12/18 12/19 12/20 12/21 Matthew
+# 12/17 12/18 12/19 12/20 12/21 12/27 12/28 12/30 Matthew
 package Apache::lonplot;
 
 use strict;
 use Apache::File;
 use Apache::response;
 use Apache::lonxml;
+use Apache::edit;
 
 sub BEGIN {
   &Apache::lonxml::register('Apache::lonplot',('plot'));
@@ -62,10 +63,12 @@ sub BEGIN {
 ##  $curves[$i]->{'data'} = [ [x1,x2,x3,x4],
 ##                            [y1,y2,y3,y4] ]
 ##
-##------------------------------------------------------------
-##
-## Tests used in checking the validitity of input
-##
+
+###################################################################
+##                                                               ##
+##        Tests used in checking the validitity of input         ##
+##                                                               ##
+###################################################################
 my $int_test       = sub {$_[0]=~s/\s+//g;$_[0]=~/^\d+$/};
 my $real_test      = 
     sub {$_[0]=~s/\s+//g;$_[0]=~/^[+-]?\d*\.?\d*([eE][+-]\d+)?$/};
@@ -75,109 +78,231 @@ my $key_pos_test   = sub {$_[0]=~/^(top|
 my $sml_test       = sub {$_[0]=~/^(small|medium|large)$/};
 my $linestyle_test = sub {$_[0]=~/^(lines|linespoints|dots|points|steps)$/};
 my $words_test     = sub {$_[0]=~s/\s+/ /g;$_[0]=~/^([\w\(\)]+ ?)+$/};
-##
-## Default values for attributes of elements
-##
+
+###################################################################
+##                                                               ##
+##                      Attribute metadata                       ##
+##                                                               ##
+###################################################################
 my %plot_defaults = 
     (
-     height       => {default => 200,       test => $int_test   },
-     width        => {default => 200,       test => $int_test   },
-     bgcolor      => {default => 'xffffff', test => $color_test },
-     fgcolor      => {default => 'x000000', test => $color_test },
-     transparent  => {default => 'off',     test => $onoff_test },
-     grid         => {default => 'off',     test => $onoff_test },
-     border       => {default => 'on',      test => $onoff_test },
-     font         => {default => 'medium',  test => $sml_test   },
-     align        => {default => 'left',    test => 
-			  sub {$_[0]=~/^(left|right|center)$/} }
+     height       => {
+	 default     => 200,
+	 test        => $int_test,
+	 description => 'vertical size of image (pixels)',
+	 edit_type   => 'entry' 
+	 },
+     width        => {
+	 default     => 200,
+	 test        => $int_test,
+	 description => 'horizontal size of image (pixels)',
+	 edit_type   => 'entry'
+	 },
+     bgcolor      => {
+	 default     => 'xffffff',
+	 test        => $color_test, 
+	 description => 'background color of image (xffffff)',
+	 edit_type   => 'entry'
+	 },
+     fgcolor      => {
+	 default     => 'x000000',
+	 test        => $color_test,
+	 description => 'foreground color of image (x000000)',
+	 edit_type   => 'entry' 
+	 },
+     transparent  => {
+	 default     => 'off',
+	 test        => $onoff_test, 
+	 description => '',
+	 edit_type   => 'on_off'
+	 },
+     grid         => {
+	 default     => 'off',
+	 test        => $onoff_test, 
+	 description => '',
+	 edit_type   => 'on_off'
+	 },
+     border       => {
+	 default     => 'on',
+	 test        => $onoff_test, 
+	 description => '',
+	 edit_type   => 'on_off'
+	 },
+     font         => {
+	 default     => 'medium',
+	 test        => $sml_test,
+	 description => 'Size of font to use',
+	 edit_type   => 'choice',
+	 choices     => ['small','medium','large']
+	 },
+     align        => {
+	 default     => 'left',
+	 test        => sub {$_[0]=~/^(left|right|center)$/},
+	 description => 'alignment for image in html',
+	 edit_type   => 'choice',
+	 choices     => ['left','right','center']
+	 } 
      );
 
 my %key_defaults = 
     (
-     title => { default => '',          test => $words_test   },
-     box   => { default => 'off',       test => $onoff_test   },
-     pos   => { default => 'top right', test => $key_pos_test }
+     title => { 
+	 default => '',
+	 test => $words_test,
+	 description => 'Title of key',
+	 edit_type   => 'entry'
+	 },
+     box   => { 
+	 default => 'off',
+	 test => $onoff_test,
+	 description => 'Draw a box around the key?',
+	 edit_type   => 'on_off'
+	 },
+     pos   => { 
+	 default => 'top right', 
+	 test => $key_pos_test, 
+	 description => 'position of the key on the plot',
+	 edit_type   => 'choice',
+	 choices     => ['top left','top right','bottom left','bottom right',
+			 'outside','below']
+	 }
      );
 
 my %label_defaults = 
     (
-     xpos    => {default => 0,         test => $real_test     },
-     ypos    => {default => 0,         test => $real_test     },
-     justify => {default => 'left',    
-                 test => sub {$_[0]=~/^(left|right|center)$/} }
+     xpos    => {
+	 default => 0,
+	 test => $real_test,
+	 description => 'x position of label (graph coordinates)',
+	 edit_type   => 'entry'
+	 },
+     ypos    => {
+	 default => 0, 
+	 test => $real_test,
+	 description => 'y position of label (graph coordinates)',
+	 edit_type   => 'entry'
+	 },
+     justify => {
+	 default => 'left',    
+	 test => sub {$_[0]=~/^(left|right|center)$/},
+	 description => 'justification of the label text on the plot',
+	 edit_type   => 'choice',
+	 choices     => ['left','right','center']
+     }
      );
 
 my %axis_defaults = 
     (
-     color     => {default => 'x000000', test => $color_test},
-     xmin      => {default => '-10.0',   test => $real_test },
-     xmax      => {default => ' 10.0',   test => $real_test },
-     ymin      => {default => '-10.0',   test => $real_test },
-     ymax      => {default => ' 10.0',   test => $real_test },
-     linestyle => {default => 'points',  test => $linestyle_test}
+     color     => {
+	 default => 'x000000', 
+	 test => $color_test,
+	 description => 'color of axes (x000000)',
+	 edit_type   => 'entry'
+	 },
+     xmin      => {
+	 default => '-10.0',
+	 test => $real_test,
+	 description => 'minimum x-value shown in plot',
+	 edit_type   => 'entry'
+	 },
+     xmax      => {
+	 default => ' 10.0',
+	 test => $real_test,
+	 description => 'maximum x-value shown in plot',	 
+	 edit_type   => 'entry'
+	 },
+     ymin      => {
+	 default => '-10.0',
+	 test => $real_test,
+	 description => 'minimum y-value shown in plot',	 
+	 edit_type   => 'entry'
+	 },
+     ymax      => {
+	 default => ' 10.0',
+	 test => $real_test,
+	 description => 'maximum y-value shown in plot',	 
+	 edit_type   => 'entry'
+	 },
+     linestyle => {
+	 default => 'points',
+	 test => $linestyle_test,
+	 description => 'Style of the axis lines',
+	 edit_type   => 'choice',
+	 choices     => ['lines','linespoints','dots','points']
+	 }
      );
 
 my %curve_defaults = 
     (
-     color     => {default => 'x000000', test => $color_test     },
-     name      => {default => '',        test => $words_test     },
-     linestyle => {default => 'lines',   test => $linestyle_test }
+     color     => {
+	 default => 'x000000',
+	 test => $color_test,
+	 description => 'color of curve (x000000)',
+	 edit_type   => 'entry'
+	 },
+     name      => {
+	 default => '',
+	 test => $words_test,
+	 description => 'name of curve to appear in key',
+	 edit_type   => 'entry'
+	 },
+     linestyle => {
+	 default => 'lines',
+	 test => $linestyle_test,
+	 description => 'Style of the axis lines',
+	 edit_type   => 'choice',
+	 choices     => ['lines','linespoints','dots','points','steps']
+	 }
      );
 
-##
-## End of defaults
-##
+###################################################################
+##                                                               ##
+##                    parsing and edit rendering                 ##
+##                                                               ##
+###################################################################
 my (%plot,%key,%axis,$title,$xlabel,$ylabel,@labels,@curves);
 
 sub start_plot {
-    %plot    = undef;   %key     = undef;   %axis   = undef; 
+    %plot    = ();      %key     = ();      %axis   = (); 
     $title   = undef;   $xlabel  = undef;   $ylabel = undef;
     $#labels = -1;      $#curves = -1;
     #
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
+    &Apache::lonxml::register('Apache::lonplot',
+	     ('title','xlabel','ylabel','key','axis','label','curve'));
+    push (@Apache::lonxml::namespace,'plot');
+    my $inside = &Apache::lonxml::get_all_text("/plot",$$parser[-1]);
     if ($target eq 'web') {
-	&Apache::lonxml::register('Apache::lonplot',
-	      ('title','xlabel','ylabel','key','axis','label','curve'));
-	push (@Apache::lonxml::namespace,'plot');
-	## Always evaluate the insides of the <plot></plot> tags
-	my $inside = &Apache::lonxml::get_all_text("/plot",$$parser[-1]);
 	$inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
-	&Apache::lonxml::newparser($parser,\$inside);
-	##-------------------------------------------------------
+    }
+    &Apache::lonxml::newparser($parser,\$inside);
+    if ($target eq 'web') {
 	&get_attributes(\%plot,\%plot_defaults,$parstack,$safeeval,
 			$tagstack->[-1]);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot');
+	$result .= &edit_attributes($target,$token,\%plot_defaults);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%plot_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+#	    $result.= &Apache::edit::handle_insert();
+	}
     }
-    return '';
+    return $result;
 }
 
 sub end_plot {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
     pop @Apache::lonxml::namespace;
     &Apache::lonxml::deregister('Apache::lonplot',
 	('title','xlabel','ylabel','key','axis','label','curve'));
     my $result = '';
     if ($target eq 'web') {
-	##
-	## Make sure we have all the input we need:
-	if (! defined(%plot  )) { &set_defaults(\%plot,\%plot_defaults); }
-	if (! defined(%key   )) {} # No key for this plot
-	if (! defined(%axis  )) { &set_defaults(\%axis,\%axis_defaults); }
-	if (! defined($title )) {} # No title for this plot
-	if (! defined($xlabel)) {} # No xlabel for this plot
-	if (! defined($ylabel)) {} # No ylabel for this plot
-	if ($#labels < 0) { } # No labels for this plot
-	if ($#curves < 0) { 
-	    &Apache::lonxml::warning("No curves specified for plot!!!!");
-	    return '';
-	}
-	my $curve;
-	foreach $curve (@curves) {
-	    if (!defined($curve->{'function'})&&!defined($curve->{'data'})){
-		&Apache::lonxml::warning("One of the curves specified did not contain any <data> or <function> declarations\n");
-		return '';
-	    }
-	}
+	&check_inputs(); # Make sure we have all the data we need
 	##
 	## Determine filename
 	my $tmpdir = '/home/httpd/perl/tmp/';
@@ -195,6 +320,8 @@ sub end_plot {
      align  = "$plot{'align'}"
      alt    = "/cgi-bin/plot.gif?$filename" />
 ENDIMAGE
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
     }
     return $result;
 }
@@ -206,7 +333,16 @@ sub start_key {
     if ($target eq 'web') {
 	&get_attributes(\%key,\%key_defaults,$parstack,$safeeval,
 		    $tagstack->[-1]);
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot Key');
+	$result .= &edit_attributes($target,$token,\%key_defaults);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%key_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	    $result.= &Apache::edit::handle_insert();
+	}
     }
     return $result;
 }
@@ -215,17 +351,26 @@ sub end_key {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
     if ($target eq 'web') {
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
     }
     return $result;
 }
+
 ##------------------------------------------------------------------- title
 sub start_title {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
     if ($target eq 'web') {
 	$title = &Apache::lonxml::get_all_text("/title",$$parser[-1]);
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token,'Plot Title');
+	my $text=&Apache::lonxml::get_all_text("/title",$$parser[-1]);
+	$result.='</td></tr><tr><td colspan="3">'.
+	    &Apache::edit::editfield('',$text,'',20,1);
+    } elsif ($target eq 'modified') {
+	my $text=$$parser[-1]->get_text("/function");
+	$result.=&Apache::edit::modifiedfield($token);
     }
     return $result;
 }
@@ -234,7 +379,8 @@ sub end_title {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
     if ($target eq 'web') {
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
     }
     return $result;
 }
@@ -244,7 +390,14 @@ sub start_xlabel {
     my $result='';
     if ($target eq 'web') {
 	$xlabel = &Apache::lonxml::get_all_text("/xlabel",$$parser[-1]);
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_start($target,$token,'Plot Xlabel');
+	my $text=&Apache::lonxml::get_all_text("/xlabel",$$parser[-1]);
+	$result.='</td></tr><tr><td colspan="3">'.
+	    &Apache::edit::editfield('',$text,'',20,1);
+    } elsif ($target eq 'modified') {
+	my $text=$$parser[-1]->get_text("/function");
+	$result.=&Apache::edit::modifiedfield($token);
     }
     return $result;
 }
@@ -253,17 +406,26 @@ sub end_xlabel {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
     if ($target eq 'web') {
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
     }
     return $result;
 }
+
 ##------------------------------------------------------------------- ylabel
 sub start_ylabel {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
     if ($target eq 'web') {
 	$ylabel = &Apache::lonxml::get_all_text("/ylabel",$$parser[-1]);
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot Ylabel');
+	my $text = &Apache::lonxml::get_all_text("/ylabel",$$parser[-1]);
+	$result .= '</td></tr><tr><td colspan="3">'.
+	    &Apache::edit::editfield('',$text,'',20,1);
+    } elsif ($target eq 'modified') {
+	my $text=$$parser[-1]->get_text("/function");
+	$result.=&Apache::edit::modifiedfield($token);
     }
     return $result;
 }
@@ -272,10 +434,12 @@ sub end_ylabel {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
     if ($target eq 'web') {
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
     }
     return $result;
 }
+
 ##------------------------------------------------------------------- label
 sub start_label {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
@@ -290,8 +454,22 @@ sub start_label {
 	    $label{'text'} = 'Illegal text';
 	}
 	push(@labels,\%label);
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot Label');
+	$result .= &edit_attributes($target,$token,\%label_defaults);
+	my $text = &Apache::lonxml::get_all_text("/label",$$parser[-1]);
+	$result .= '</td></tr><tr><td colspan="3">'.
+	    &Apache::edit::editfield('',$text,'',20,1);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%label_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	    $result.= &Apache::edit::handle_insert();
+	}
+	my $text=$$parser[-1]->get_text("/label");
+	$result.=&Apache::edit::modifiedfield($token);
     }
-    # This routine should never return anything.
     return $result;
 }
 
@@ -299,7 +477,8 @@ sub end_label {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
     if ($target eq 'web') {
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
     }
     return $result;
 }
@@ -308,14 +487,23 @@ sub end_label {
 sub start_curve {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result='';
+    &Apache::lonxml::register('Apache::lonplot',('function','data'));
+    push (@Apache::lonxml::namespace,'curve');
     if ($target eq 'web') {
 	my %curve;
 	&get_attributes(\%curve,\%curve_defaults,$parstack,$safeeval,
 		    $tagstack->[-1]);
 	push (@curves,\%curve);
-	&Apache::lonxml::register('Apache::lonplot',('function','data'));
-	push (@Apache::lonxml::namespace,'curve');
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Curve');
+	$result .= &edit_attributes($target,$token,\%curve_defaults);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%label_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	    $result.= &Apache::edit::handle_insert();
+	}
     }
     return $result;
 }
@@ -323,13 +511,15 @@ sub start_curve {
 sub end_curve {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
+    pop @Apache::lonxml::namespace;
+    &Apache::lonxml::deregister('Apache::lonplot',('function','data'));
     if ($target eq 'web') {
-	pop @Apache::lonxml::namespace;
-	&Apache::lonxml::deregister('Apache::lonplot',('function','data'));
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
     }
     return $result;
 }
+
 ##------------------------------------------------------------ curve function
 sub start_function {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
@@ -341,7 +531,15 @@ sub start_function {
 	}
 	$curves[-1]->{'function'} = 
 	    &Apache::lonxml::get_all_text("/function",$$parser[-1]);
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Curve Function');
+	my $text = &Apache::lonxml::get_all_text("/function",$$parser[-1]);
+	$result .= '</td></tr><tr><td colspan="3">'.
+	    &Apache::edit::editfield('',$text,'',20,1);
+    } elsif ($target eq 'modified') {
+	# Why do I do this?
+	my $text=$$parser[-1]->get_text("/function");
+	$result.=&Apache::edit::modifiedfield($token);
     }
     return $result;
 }
@@ -350,10 +548,12 @@ sub end_function {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
     if ($target eq 'web') {
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::end_table();
     }
     return $result;
 }
+
 ##------------------------------------------------------------ curve  data
 sub start_data {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
@@ -393,7 +593,14 @@ sub start_data {
 	    }
 	}
 	push  @{$curves[-1]->{'data'}},\@data;
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Curve Data');
+	my $text = &Apache::lonxml::get_all_text("/data",$$parser[-1]);
+	$result .= '</td></tr><tr><td colspan="3">'.
+	    &Apache::edit::editfield('',$text,'',20,1);
+    } elsif ($target eq 'modified') {
+	my $text=$$parser[-1]->get_text("/data");
+	$result.=&Apache::edit::modifiedfield($token);
     }
     return $result;
 }
@@ -402,7 +609,8 @@ sub end_data {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
     if ($target eq 'web') {
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::end_table();
     }
     return $result;
 }
@@ -414,7 +622,10 @@ sub start_axis {
     if ($target eq 'web') {
 	&get_attributes(\%axis,\%axis_defaults,$parstack,$safeeval,
 			$tagstack->[-1]);
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result .= &Apache::edit::tag_start($target,$token,'Plot Axes');
+	$result .= &edit_attributes($target,$token,\%axis_defaults);
+    } elsif ($target eq 'modified') {
     }
     return $result;
 }
@@ -423,29 +634,38 @@ sub end_axis {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result = '';
     if ($target eq 'web') {
-	# This routine should never return anything.
+    } elsif ($target eq 'edit') {
+	$result.=&Apache::edit::tag_end($target,$token);
+    } elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args
+	    ($token,$parstack,$safeeval,keys(%axis_defaults));
+	if ($constructtag) {
+	    $result = &Apache::edit::rebuild_tag($token);
+	    $result.= &Apache::edit::handle_insert();
+	}
     }
     return $result;
 }
 
+###################################################################
+##                                                               ##
+##        Utility Functions                                      ##
+##                                                               ##
+###################################################################
+
 ##----------------------------------------------------------- set_defaults
 sub set_defaults {
-    my $var      = shift;
-    my $defaults = shift;
+    my ($var,$defaults) = @_;
     my $key;
-    foreach $key (keys %$defaults) {
+    foreach $key (keys(%$defaults)) {
 	$var->{$key} = $defaults->{$key}->{'default'};
     }
 }
 
 ##------------------------------------------------------------------- misc
 sub get_attributes{
-    my $values   = shift;
-    my $defaults = shift;
-    my $parstack = shift;
-    my $safeeval = shift;
-    my $tag      = shift;
-    foreach my $attr (keys %{$defaults}) {
+    my ($values,$defaults,$parstack,$safeeval,$tag) = @_;
+    foreach my $attr (keys(%{$defaults})) {
 	$values->{$attr} = 
 	    &Apache::lonxml::get_param($attr,$parstack,$safeeval);
 	if ($values->{$attr} eq '' | !defined($values->{$attr})) {
@@ -492,12 +712,12 @@ sub write_gnuplot_file {
     $gnuplot_input .= "set title  \"$title\"\n"  if (defined($title)) ;
     $gnuplot_input .= "set xlabel \"$xlabel\"\n" if (defined($xlabel));
     $gnuplot_input .= "set ylabel \"$ylabel\"\n" if (defined($ylabel));
-    if (defined(%axis)) {
+    if (%axis) {
 	$gnuplot_input .= "set xrange \[$axis{'xmin'}:$axis{'xmax'}\]\n";
 	$gnuplot_input .= "set yrange \[$axis{'ymin'}:$axis{'ymax'}\]\n";
     }
     # Key
-    if (defined(%key)) {
+    if (%key) {
 	$gnuplot_input .= 'set key '.$key{'pos'}.' ';
 	if ($key{'title'} ne '') {
 	    $gnuplot_input .= 'title "'.$key{'title'}.'" ';
@@ -543,10 +763,142 @@ sub write_gnuplot_file {
     return $gnuplot_input;
 }
 
-1;
-__END__
+#---------------------------------------------- check_inputs
+sub check_inputs {
+    ## Note: no inputs, no outputs - this acts only on global variables.
+    ## Make sure we have all the input we need:
+    if (! %plot) { &set_defaults(\%plot,\%plot_defaults); }
+    if (! %key ) {} # No key for this plot, thats okay
+    if (! %axis) { &set_defaults(\%axis,\%axis_defaults); }
+    if (! defined($title )) {} # No title for this plot, thats okay
+    if (! defined($xlabel)) {} # No xlabel for this plot, thats okay
+    if (! defined($ylabel)) {} # No ylabel for this plot, thats okay
+    if ($#labels < 0) { }      # No labels for this plot, thats okay
+    if ($#curves < 0) { 
+	&Apache::lonxml::warning("No curves specified for plot!!!!");
+	return '';
+    }
+    my $curve;
+    foreach $curve (@curves) {
+	if (!defined($curve->{'function'})&&!defined($curve->{'data'})){
+	    &Apache::lonxml::warning("One of the curves specified did not contain any <data> or <function> declarations\n");
+	    return '';
+	}
+    }
+}
+
+#------------------------------------------------ make_edit
+sub edit_attributes {
+    my ($target,$token,$defaults) = @_;
+    my $result;
+    foreach my $attr (sort keys(%$defaults)) {
+	if ($defaults->{$attr}->{'edit_type'} eq 'entry') {
+	    $result .= &Apache::edit::text_arg(
+                 $defaults->{$attr}->{'description'},
+		 $attr,
+		 $token);
+	} elsif ($defaults->{$attr}->{'edit_type'} eq 'choice') {
+	    $result .= &Apache::edit::select_arg(
+		 $defaults->{$attr}->{'description'},
+		 $attr,
+		 $defaults->{$attr}->{'choices'},
+		 $token);
+	}
+	$result .= '<br />';
+    }
+    return $result;
+}
+
 
+###################################################################
+##                                                               ##
+##           Insertion functions for editing plots               ##
+##                                                               ##
+###################################################################
 
+#------------------------------------------------ insert_xxxxxxx
+sub insert_plot {
+    my $result;
+    #  plot attributes
+    $result .= '<plot ';
+    foreach my $attr (%plot_defaults) {
+	$result .= '     '.$attr.'="'.$plot_defaults{$attr}->{'default'}.
+	    "\"\n";
+    }
+    $result .= ">\n";
+    # Add the components
+    $result .= &insert_key();
+    $result .= &insert_axis();
+    $result .= &insert_label();    
+    $result .= &insert_curve();
+    $result .= &insert_function();    
+    $result .= "</curve>\n";
+    $result .= &insert_curve();
+    $result .= &insert_data();    
+    $result .= "</curve>\n";
+    # close up the <plot>
+    $result .= "</plot>\n";
+    return $result;
+}
 
+sub insert_key {
+    my $result;
+    $result .= '    <key ';
+    foreach my $attr (%key_defaults) {
+	$result .= '         '.$attr.'="'.$key_defaults{$attr}->{'default'}.
+	    "\"\n";
+    }
+    $result .= "   />\n";
+    return $result;
+}
+
+sub insert_axis{
+    my $result;
+    $result .= '    <axis ';
+    foreach my $attr (%axis_defaults) {
+	$result .= '         '.$attr.'="'.$axis_defaults{$attr}->{'default'}.
+	    "\"\n";
+    }
+    $result .= "   />\n";
+    return $result;
+}
+
+sub insert_label {
+    my $result;
+    $result .= '    <label ';
+    foreach my $attr (%label_defaults) {
+	$result .= '         '.$attr.'="'.
+	    $label_defaults{$attr}->{'default'}."\"\n";
+    }
+    $result .= "   ></label>\n";
+    return $result;
+}
+
+sub insert_curve {
+    my $result;
+    $result .= '    <curve ';
+    foreach my $attr (%curve_defaults) {
+	$result .= '         '.$attr.'="'.
+	    $curve_defaults{$attr}->{'default'}."\"\n";
+    }
+    $result .= "    >\n";
+}
+
+sub insert_function {
+    my $result;
+    $result .= "<function></function>\n";
+    return $result;
+}
+
+sub insert_data {
+    my $result;
+    $result .= "     <data></data>\n";
+    $result .= "     <data></data>\n";
+    return $result;
+}
+
+##----------------------------------------------------------------------
+1;
+__END__