show empty form without sql

diff --git a/web_ui.pl b/web_ui.pl
index cd6ec93..fd02c89 100755 (executable)
--- a/web_ui.pl
+++ b/web_ui.pl
@@ -78,7 +78,8 @@ get '/_g/status' => sub {
 get '/gnuplot' => sub {
        my $self = shift;
 
-       my $sql = $self->param('sql') || die "sql required";
+       my $sql = $self->param('sql');
+       return $self->render('gnuplot', img => '', gnuplot => '') unless $sql;
 
        my $ret = $gearman->req( 'SUBMIT_JOB', 'Store_sql', '', $sql );
        die "no result for $sql" unless $ret;
@@ -178,9 +179,11 @@ pong: <tt><%= $pong %>
 % layout 'default';
 <%= form_for gnuplot => begin %>
  <%= text_area 'sql', cols => 80 %>
- <%= submit_button %>
+ <%= submit_button 'execute' %>
 <% end %>
+% if ( $img ) {
 <img src="<%= $img %>">
+% }
 <pre><%= $gnuplot %></pre>
 
 @@ layouts/default.html.ep