Repairing export failure

Added support for handling characters not allowed in MS Excel

app/views/admin/seminars/export.xlsx.axlsx

@@ -2,7 +2,12 @@
 
 wb = xlsx_package.workbook
 
-wb.add_worksheet(name: (@seminar.title.to_s[0..27]+'...')) do |sheet|
+illegal_chars = /[:\\\/\[\]\*\?]/
+
+sanitized_title = @seminar.title.to_s.gsub(illegal_chars, ' ').strip
+sheet_name = (sanitized_title[0..27] + '...').gsub(/\.{4,}/, '...')
+
+wb.add_worksheet(name: sheet_name) do |sheet|
 
   row = [t('seminar_signup.signup_time')]
 
@@ -26,7 +31,7 @@ wb.add_worksheet(name: (@seminar.title.to_s[0..27]+'...')) do |sheet|
 
   seminar_signup_fields = @seminar.seminar_signup_fields.where(:disabled=>false).asc(:sort_number, :_id).to_a
 
-  seminar_signup_fields.each  do |rf| 
+  seminar_signup_fields.each do |rf|
     if rf.can_muti_lang_input?
       @site_in_use_locales.each do |l|
         row << rf.title + " (#{t(l.to_s)})"
@@ -35,9 +40,10 @@ wb.add_worksheet(name: (@seminar.title.to_s[0..27]+'...')) do |sheet|
       row << rf.title
     end
   end
+  
   highlight_style = wb.styles.add_style(
     :bg_color => 'ffeb3b',
-    :b        => true,
+    :b => true,
     :border => { :style => :thick, :color => "000000", :edges => [:top, :left, :bottom, :right] },
     :alignment => {:horizontal => :center, :vertical => :center, :wrap_text => true}
   )
@@ -52,13 +58,13 @@ wb.add_worksheet(name: (@seminar.title.to_s[0..27]+'...')) do |sheet|
     row2 << "#{signup.display_serial_number}"
     row2 << "#{signup[:name]} "
     row2 << "#{signup.unit} "
-    row2 << "#{signup[:tel]} "
+    row2 << "#{signup.tel} "
     row2 << "#{signup[:phone]} "
     row2 << "#{signup[:fax]} "
     row2 << "#{signup.address} "
     row2 << "#{signup[:email]} "
     row2 << "#{signup.note} "
-    seminar_signup_fields.each  do |rf| 
+    seminar_signup_fields.each do |rf|
       if rf.can_muti_lang_input?
         @site_in_use_locales.each do |l|
           row2 << (@seminar.get_attribute_value(rf,signup.id).get_value_by_locale(l) rescue '')
@@ -76,5 +82,4 @@ wb.add_worksheet(name: (@seminar.title.to_s[0..27]+'...')) do |sheet|
     sheet.add_row row2 , :types => types, :style => styles
   end
 
-end
-
+end