all shared procs move to library file

Ignore-this: 75e219cb44fc45e281a42d514cf2600f

darcs-hash:20110125023430-067c0-ed0225f6b7d24c31e9f8eb4498a04191abf7f355.gz

1 files changed, 809 insertions, 0 deletions

diff --git a/GradeBook_lib.tcl b/GradeBook_lib.tcl
new file mode 100755
index 0000000..4987b7d
--- /dev/null
+++ b/GradeBook_lib.tcl
@@ -0,0 +1,809 @@
+#!/bin/sh
+# (C) 2010 by Eugeniy Mikhailov, <evgmik@gmail.com>
+# vim:set ft=tcl: \
+exec tclsh "$0" "$@"
+
+# internal version of this code
+set VERSION 1.0
+
+# ########################## procs begin #################################
+proc dbg {msg {level 1}} {
+	if { $level <=2 } {
+		set fid [open log a+]
+		puts $fid $msg 
+		close $fid
+	}
+}
+
+proc ColName2SqlSafeForm {colname} {
+	set bad_symbols [list {\}} {\{} {\\} {\'} {\"} {\]} {\[} ]
+	foreach bs $bad_symbols {
+		regsub -all $bs $colname "" colname 
+	}
+	return $colname
+}
+
+proc AddUserNonWeb { first_name last_name user_name password_hash {group_name {guest}} {id_number {}} {section_num {} } } {
+	set eval_str [concat INSERT INTO GradesTable (FirstName, LastName, UserName, PasswordHash, GroupName, IdNum, SectionNum) VALUES('$first_name', '$last_name', '$user_name', '$password_hash', '$group_name', '$id_number', '$section_num')]
+	set err [catch {db eval $eval_str  } errStat]
+	if { $err } {
+		htmlErrorMsg  $errStat 
+		dbg  "the following error happen: $errStat" 3
+	} 
+}
+
+proc CreateGradesTable {db} {
+	set err [catch {db eval {CREATE TABLE GradesTable(FirstName text, LastName text, UserName text, PasswordHash text, GroupName text, UserHiddenColums text, UserHiddenGroups text, IdNum text, SectionNum text)} } errStat] 
+	if { $err } {
+		htmlErrorMsg  $errStat 
+		dbg  "the following error happen: $errStat" 1
+	} 
+
+	# add special users aka special info rows
+	AddUserNonWeb  {} {}  _Col_Category_ {} inforow
+	AddUserNonWeb  {} {}  _Max_Points_   {} inforow
+
+	# reasonable defaults for hidden columns
+	#set instructor_hidden_columns [list UserHiddenColums PasswordHash UserHiddenGroups IdNum]
+	#UpdateColValue4GroupNameNonWeb UserHiddenColums instructor $instructor_hidden_columns
+}
+
+proc AddAccessRightNonWeb { action instructor_right ta_right student_right guest_right } {
+	set eval_str [concat INSERT INTO AccessRightsTable (actionname, instructor, ta, student, guest) VALUES('$action', '$instructor_right', '$ta_right', '$student_right', '$guest_right')]
+	set err [catch {db eval $eval_str  } errStat]
+	if { $err } {
+		htmlErrorMsg  $errStat 
+		dbg  "the following error happen: $errStat" 3
+	} 
+}
+
+proc CreateAccessRightsTable {db} {
+	set err [catch {db eval {CREATE TABLE AccessRightsTable(actionname text,               instructor integer, ta integer, student integer,  guest integer)} } errStat]
+	if { $err } {
+		htmlErrorMsg  $errStat 
+		dbg  "the following error happen: $errStat" 1
+	} 
+	# guest should have no rights make sure that 0 is evereywhere except logon
+	#                    actionname        instructor   ta   student  guest
+	AddAccessRightNonWeb logon             1            1    1        1
+	AddAccessRightNonWeb showgrades        1            1    1        0
+	AddAccessRightNonWeb sort              1            1    0        0
+	AddAccessRightNonWeb addcolumnrequest  1            1    0        0
+	AddAccessRightNonWeb addcolumn         1            1    0        0
+	AddAccessRightNonWeb deletecolumn      1            1    0        0
+	AddAccessRightNonWeb showcontrols      1            1    1        0
+	AddAccessRightNonWeb changegrades      1            1    0        0
+	AddAccessRightNonWeb updategrades      1            1    0        0
+	AddAccessRightNonWeb changecolumn      1            1    0        0
+	AddAccessRightNonWeb updatecolumn      1            1    0        0
+	AddAccessRightNonWeb logoff            1            1    1        0
+	AddAccessRightNonWeb changefirstname   1            0    0        0
+	AddAccessRightNonWeb changelastname    1            0    0        0
+	AddAccessRightNonWeb changeusername    1            0    0        0
+	AddAccessRightNonWeb userhidecolumn    1            1    1        0
+	AddAccessRightNonWeb userunhidecolumn  1            1    1        0
+	AddAccessRightNonWeb userhidegroup     1            0    0        0
+	AddAccessRightNonWeb userunhidegroup   1            0    0        0
+}
+
+proc htmlErrorMsg { msg } {
+			puts "<div class=\"errormsg\">error: $msg</div>"
+}
+
+proc htmlReplaceEmptyString { string } {
+	#  empty string replaced with "---"
+	regsub {^$} $string "---" string 
+	# white spaces only string replaced with "---"
+	regsub {^\s+$} $string "---" string 
+	set string
+}
+
+proc htmlDBout {db permission_list user {sort_col {}}} {
+	array set permission $permission_list
+	global script_name
+	set defSortCol LastName 
+
+	if { $sort_col == {} } {
+		set sort_col $defSortCol 
+		dbg "empty sort col changed to $sort_col" 4
+	} 
+	# testing for the existense of the sorting column
+	set eval_str [list SELECT * FROM GradesTable ORDER BY $sort_col]
+	set err [catch {db eval $eval_str } errStat]
+	if { $err } {
+		dbg $errStat 3
+		dbg "changing to default sorting column $defSortCol" 3
+		set sort_col $defSortCol
+	}
+
+	puts  {<div class="gradestable">}
+	set show_header 1
+	# get names of all columns
+	set column_list [getColListFromTable GradesTable]
+	# set hidden column list
+	switch $permission(GroupName) {
+		instructor { set hidden_columns {} }
+		ta         { set hidden_columns [list UserName PasswordHash GroupName UserHiddenColums UserHiddenGroups IdNum] }
+		student    { set hidden_columns [list FirstName LastName  UserName PasswordHash GroupName UserHiddenColums UserHiddenGroups  IdNum SectionNum] }
+		guest      { set hidden_columns $column_list }
+		default    { set hidden_columns $column_list }
+	}
+	# add user hidden columns
+	set hidden_columns [concat $hidden_columns [SelectColValue4User UserHiddenColums $user]]
+	# remove hidden columns from sql request
+	foreach col $hidden_columns {
+		set column_list [removeElementFromList $col $column_list]
+	}
+	set sql_column_str [colList2sqlColStr $column_list]
+	# set users of what group user can see, i.e. set WHERE statement
+	set where_statement {}
+	switch $permission(GroupName) {
+		instructor { 
+			# hide unwanted user groups
+			set user_groups_for_hide [SelectColValue4User UserHiddenGroups $user]
+			if {$user_groups_for_hide != {} } {
+				foreach grp $user_groups_for_hide {
+					if { $where_statement == {} } {
+						set where_statement "WHERE GroupName<>\"$grp\""
+					} else {
+						set where_statement [concat $where_statement "AND GroupName<>\"$grp\""]
+					}
+				}
+			}
+		}
+		ta         { set where_statement "WHERE GroupName=\"student\"" }
+		student    { set where_statement "WHERE UserName=\"$user\"" }
+		guest      { dbg "Guest must not be allowed to set table view port. Aborting. This line is never executed" 0; exit }
+		default      { dbg "Default must not be allowed to set table view port. Aborting. This line is never executed." 0; exit }
+	}
+	if { $sql_column_str ne "" } {
+		# get all allowed columns and rows
+		set eval_str [concat SELECT $sql_column_str FROM GradesTable $where_statement ORDER BY $sort_col]
+		set err [catch {
+				db eval $eval_str v {
+					if { $show_header } {
+						set show_header 0
+						puts  {<table class="gradestable" border="1">}
+						puts  "<tr>"
+						foreach col  $v(*) {
+							# detect what column category it is
+							set category [SelectColValue4User $col _Col_Category_]
+							puts -nonewline "<th class=\"$category\"><a href=\"$script_name?action=sort&sortCol=$col\">$col</a>"
+							# below list has action and action_label pairs
+							set action_list {userhidecolumn hide}
+							switch $col {
+								FirstName { lappend action_list changefirstname "change first name" }
+								LastName  { lappend action_list changelastname "change last name" }
+								UserName  { lappend action_list changeusername "change user name" }
+								PasswordHash  { }
+								UserHiddenColums { } 
+								UserHiddenGroups { } 
+								IdNum { } 
+								GroupName  {   }
+								SectionNum {   }
+								default {
+									lappend action_list changegrades "change grades" deletecolumn delete  changecolumn "change column"
+								}
+							}
+							set separator {<br>}
+							foreach {act act_label} $action_list {
+								if { [isActionGranted $act $permission_list $user] } {
+									puts -nonewline "$separator<span class=\"controls\"><a href=\"$script_name?action=$act&columnname=[::ncgi::encode $col]\">$act_label</a></span>"
+								} 
+							}
+							puts -nonewline "</th>"
+							puts ""
+						}
+						puts "</tr>"
+						puts  "<tr>"
+					} else {
+						puts  "<tr>"
+					}
+					foreach index $v(*) {
+						if { $index != "*" } {
+							# detect what column category it is
+							set category [SelectColValue4User $index _Col_Category_]
+							set col_value [htmlReplaceEmptyString $v($index)]
+							puts -nonewline "<td class=\"$category\">$col_value</td>"
+						}
+					}
+					puts "</tr>"
+				}
+			} errStat ]
+		if { $err } {
+			dbg "we should never be here if $sortCol exist in the table" 1
+			dbg $errStat 1
+			htmlErrorMsg $errStat
+		}
+		puts  "</table>"
+	} else {
+		puts {There is no grades yet.}
+	}
+	puts  {</div>}
+}
+
+proc htmlTop {permission_list} {
+	array set permission $permission_list
+	if { $permission(GroupName) == "guest" } {
+		askToLogin
+	} else {
+		Greetings
+	}
+
+}
+
+proc htmlFooter {permission_list} {
+	array set permission $permission_list
+	global VERSION
+	puts "<div class=\"footer\">"
+	puts "GradeBook $VERSION code is written by Eugeniy E. Mikhailov"
+	puts "</div>"
+}
+
+
+proc SelectColValue4User { colname user } {
+	set value {}
+	set eval_str "SELECT \"$colname\"  FROM GradesTable  where UserName=\"$user\""
+	set err [catch {
+		db eval $eval_str v {
+			set value $v($colname)
+		}
+	} errStat ]
+	if { $err } {
+		htmlErrorMsg  $errStat 
+		dbg  "the following error happen: $errStat" 3
+	} 
+	return $value
+}
+
+proc Greetings {} {
+	global user password script_name
+
+	set FirstName UnknownFirstName
+	set LastName  UnknownLastName
+
+	# get First and Last name info
+	set FirstName [SelectColValue4User FirstName $user]
+	set LastName  [SelectColValue4User LastName  $user]
+	
+	puts "<div class=\"greetings\">"
+	puts "<span class=login_info>$FirstName $LastName</span>, you  are logged in as <span class=login_info>$user</span>."
+	#puts "<a href=\"$script_name?action=logoff\">logoff</a>"
+	puts "</div>"
+	
+}
+
+proc askToLogin {} {
+	global script_name
+	global user password
+	puts "<div class=\"login\">"
+	puts "Either you are here first time or you password and user name does not match. <br>"
+	puts "Please login <br>"
+	puts "<form name=\"input\" action=\"$script_name\" method=\"post\" />"
+	puts "Login: <input type=\"text\" name=\"user\" value=\"$user\"><br>"
+	puts {Password: <input type="password" name="password"><br>}
+	puts {<input type="hidden" name="action" value="logon"/>}
+	puts {<input type="submit" value="Submit" />}
+	puts {</form>}
+	puts "</div>"
+}
+
+proc LogMeOn {} {
+	global user password
+	set user [::ncgi::value user guest]
+	set password [::ncgi::value password guest]
+	dbg "Logging in and setting cookies" 4
+	::ncgi::setCookie  -name user -value $user
+	::ncgi::setCookie  -name password -value $password
+}
+
+proc LogMeOff {} {
+	dbg "Logging off" 4
+	global user password
+	#set user guest
+	set password {}
+	#::ncgi::setCookie  -name user -value $user
+	::ncgi::setCookie  -name password -value $password
+}
+
+proc SetSortColumn {} {
+	global sortCol 
+	set sortCol [::ncgi::value sortCol LastName]
+	::ncgi::setCookie  -name sortCol -value $sortCol
+}
+
+proc isActionGranted { action permission_list user } {
+	array set permission $permission_list
+	if { $action == "defaultview" } { 
+		# this one permitted to everyone
+		dbg "requested action $action for user $user is granted" 4
+		return 1;
+	}
+	if { ![info exist permission($action) ] } {
+		dbg "requested UNKNOWN action $action for user $user is not granted" 0
+		htmlErrorMsg "requested UNKNOWN action $action"
+		return 0;
+	}
+
+	if {$permission($action) } {
+		dbg "requested action $action for user $user is granted" 4
+		return 1;
+	} else {
+		dbg "requested action $action for user $user is not granted" 1
+		return 0;
+	}
+}
+
+proc ChoseAction {action permission_list user} {
+	array set permission $permission_list
+	dbg "requested action: $action" 1
+	if { [isActionGranted $action $permission_list $user] } {
+
+		switch $action {
+			sort             { SetSortColumn; ChoseAction defaultview $permission_list $user } 
+			addcolumn        { 
+				           AddColumn          $permission_list  $user;
+				           htmlDefaultView    $permission_list  $user
+					 } 
+			addcolumnrequest { AddColumnRequest   $permission_list  $user } 
+			deletecolumn     { 
+			                   DeleteColumn       $permission_list  $user;
+				           htmlDefaultView    $permission_list  $user
+			                 } 
+			changegrades	 { ChangeGrades       $permission_list  $user }	 
+			updategrades     { UpdateGrades       $permission_list  $user 
+				           htmlDefaultView    $permission_list  $user
+			                 } 
+			changecolumn     { ChangeColumn       $permission_list  $user }
+			updatecolumn     { UpdateColumn       $permission_list  $user 
+				           htmlDefaultView    $permission_list  $user
+					 }
+			showcontrols     { ShowControls       $permission_list  $user } 
+			userhidecolumn   { UserHideColumn     $permission_list  $user 
+				           htmlDefaultView    $permission_list  $user }
+			userunhidecolumn { UserUnHideColumn     $permission_list  $user 
+				           htmlDefaultView    $permission_list  $user }
+			userhidegroup   { UserHideGroup     $permission_list  $user 
+				           htmlDefaultView    $permission_list  $user }
+			userunhidegroup { UserUnHideGroup     $permission_list  $user 
+				           htmlDefaultView    $permission_list  $user }
+			showgrades       { htmlGradesTable db $permission_list  $user }
+			defaultview      { htmlDefaultView    $permission_list  $user }
+			default          { htmlErrorMsg "requested action <b>$action</b> is granted but not implemented yet" }
+		}	
+	} else {
+		# this action is permitted to everyone by default
+		ChoseAction defaultview $permission_list $user
+	}
+}
+
+proc UserUnHideGroup { permission_list user } {
+	set groupname [::ncgi::value groupname {}]
+	set currently_hidden_groups [SelectColValue4User UserHiddenGroups $user]
+	set currently_hidden_groups [removeElementFromList $groupname $currently_hidden_groups]
+	UpdateColValue4UserNameNonWeb UserHiddenGroups $user $currently_hidden_groups
+}
+proc UserHideGroup { permission_list user } {
+	set groupname [::ncgi::value groupname {}]
+	set currently_hidden_groups [SelectColValue4User UserHiddenGroups $user]
+	lappend currently_hidden_groups $groupname
+	UpdateColValue4UserNameNonWeb UserHiddenGroups $user $currently_hidden_groups
+}
+
+proc UserHideColumn { permission_list user } {
+	set columnname [::ncgi::value columnname {}]
+	set currently_hidden_columns [SelectColValue4User UserHiddenColums $user]
+	lappend currently_hidden_columns $columnname
+	UpdateColValue4UserNameNonWeb UserHiddenColums $user $currently_hidden_columns
+}
+
+proc UserUnHideColumn { permission_list user } {
+	set columnname [::ncgi::value columnname {}]
+	set currently_hidden_columns [SelectColValue4User UserHiddenColums $user]
+	set currently_hidden_columns [removeElementFromList $columnname $currently_hidden_columns]
+	UpdateColValue4UserNameNonWeb UserHiddenColums $user $currently_hidden_columns
+}
+
+proc ChangeColumn { permission_list user } {
+	set columnname [::ncgi::value columnname {}]
+	set category "unset"
+	set category  [SelectColValue4User $columnname _Col_Category_]
+	set maxpoints [SelectColValue4User $columnname _Max_Points_]
+
+	puts {<div class="add_new_column">}
+	puts "<form name=\"input\"  method=\"post\" />"
+	set out_str {}
+	append out_str {Column Name: <input type="text" name="newcolumnname" value="} $columnname {"><br>}
+	puts $out_str
+	set out_str {}
+	append out_str {Category: <select name="category" value="} $category  {">}
+	puts $out_str
+	# opt list has option name and corresponding text pairs
+	set opt_list [list \
+		unset --Select--\
+	       	Quiz Quiz\
+	       	HomeWork HomeWork\
+	       	LabReport LabReport\
+	       	MidTerm MidTerm\
+	       	FinalExam FinalExam\
+		]
+	foreach {name txt} $opt_list {
+		set out_str {}
+		if { $name eq $category } {
+			append out_str {<option value="} $name {" selected>} $txt {</option>}
+		} else {
+			append out_str {<option value="} $name {">} $txt {</option>}
+		}
+
+		puts $out_str
+	}	
+	puts {</select> <br>}
+	set out_str {}
+	append out_str {Max Point Possible:<input type="text" name="maxpointpossible" value="} $maxpoints {"> <br>}
+	puts $out_str
+	puts {<input type="hidden" name="action" value="updatecolumn"/>}
+	set out_str {}
+	append out_str {<input type="hidden" name="oldcolumnname" value="} $columnname {"/>}
+	puts $out_str
+	puts {<input type="submit" value="Submit" />}
+	puts {</form>}
+	puts {</div>}
+}
+
+proc UpdateColumn { permission_list user } {
+	set oldcolumnname [::ncgi::value oldcolumnname {}]
+	set newcolumnname [::ncgi::value newcolumnname {}]
+	set column_category [::ncgi::value category {}]
+	set maxpointpossible [::ncgi::value maxpointpossible {}]
+
+	# transform colnames to sql safe form
+	set oldcolumnname [ColName2SqlSafeForm $oldcolumnname]
+	set newcolumnname [ColName2SqlSafeForm $newcolumnname]
+
+	# first we update category and maxpointpossible values of the old columnname
+	UpdateColValue4UserNameNonWeb $oldcolumnname _Col_Category_ $column_category
+	UpdateColValue4UserNameNonWeb $oldcolumnname _Max_Points_   $maxpointpossible
+
+	if { $newcolumnname eq $oldcolumnname } {
+		# no need to mess with renaming
+		return
+	}
+	if { $newcolumnname == "" } {
+		htmlErrorMsg  "empty column names are not permitted"
+		return
+	}
+	set eval_str [concat SELECT * FROM GradesTable ]
+	set err [catch {db eval $eval_str v {} } errStat]
+	set old_column_list $v(*)
+	# check if column with the suggested new name is already exist
+	foreach cname $old_column_list {
+		if { $cname eq $newcolumnname } {
+			htmlErrorMsg  "The column name <b>$newcolumnname</b> is already exist"
+			return
+		}
+	}
+	# sqlite does not allow rename columns
+	# I will first create new column identical to the old one
+	AddColumnNonWeb  $newcolumnname $column_category $maxpointpossible 
+	set sql_str [concat UPDATE  GradesTable SET \"$newcolumnname\"=\"$oldcolumnname\"]
+	set err [catch {db eval $sql_str } errStat]
+	# then delete the old one
+	DeleteColumnNonWeb $oldcolumnname
+}
+
+proc UpdateColValue4UserNameNonWeb { columnname username val } {
+					set sql_str [concat UPDATE  GradesTable SET \"$columnname\"=\'$val\' where UserName=\"$username\"]
+					set err2 [catch {
+						db eval $sql_str
+					} errStat2 ]
+					if { $err2 } {
+						htmlErrorMsg  $errStat2 
+						dbg  "the following error happen: $errStat2" 3
+					} 
+}
+
+proc UpdateColValue4GroupNameNonWeb { columnname groupname val } {
+					set sql_str [concat UPDATE  GradesTable SET \"$columnname\"=\'$val\' where GroupName=\"$groupname\"]
+					set err2 [catch {
+						db eval $sql_str
+					} errStat2 ]
+					if { $err2 } {
+						htmlErrorMsg  $errStat2 
+						dbg  "the following error happen: $errStat2" 3
+					} 
+}
+
+proc UpdateGrades { permission_list user } {
+	global script_name
+	set subaction [::ncgi::value subaction {}]
+	set columnname [::ncgi::value columnname {}]
+	set nv [::ncgi::nvlist]
+	array set colval  $nv
+	if { $subaction eq "Submit" } {
+		set eval_str "SELECT UserName  FROM GradesTable"
+		set err [catch {
+				db eval $eval_str v {
+					if { [info exist colval($v(UserName))] } {	
+						UpdateColValue4UserNameNonWeb $columnname $v(UserName) $colval($v(UserName))
+					}
+				}
+			} errStat ]
+		if { $err } {
+			htmlErrorMsg  $errStat 
+			dbg  "the following error happen: $errStat" 3
+		} 
+	}
+}
+
+proc ChangeGrades { permission_list user } {
+	global script_name
+	set columnname [::ncgi::value columnname {}]
+	if { $columnname != "" } {
+		# output only selected columns
+		set column_list {}
+		lappend column_list FirstName LastName UserName
+		lappend column_list \"$columnname\"
+		set sql_column_list [join $column_list ","]
+		puts {<div class="changegrades">}
+		puts {<div class="gradestable">}
+		puts "<form name=\"input\" action=\"$script_name\" method=\"post\" />"
+		# output only selected columns
+		set eval_str "SELECT $sql_column_list  FROM GradesTable WHERE UserName<>'_Col_Category_' AND UserName<>'_Max_Points_' AND GroupName='student' ORDER BY LastName"
+		set show_header 1
+		set err [catch {
+				db eval $eval_str v {
+					if { $show_header } {
+						set show_header 0
+						puts  {<table class="gradestable" border="1">}
+						puts  "<tr>"
+						foreach col  $v(*) {
+							puts -nonewline "<th>$col</th>"
+						}
+						puts  "<tr>"
+					} else {
+						puts  "<tr>"
+					}
+					foreach index $v(*) {
+						if { $index != "*" } {
+							if { $index eq $columnname } {
+								#column with grade
+								puts "<th><input type=\"text\" name=\"$v(UserName)\" value=\"$v($columnname)\" size=5></th>"
+							} else {
+								puts -nonewline "<td>$v($index)</td>"
+							}
+						}
+					}
+					puts "</tr>"
+				}
+			} errStat ]
+		puts  "</table>"
+		if { $err } {
+			htmlErrorMsg  $errStat 
+			dbg  "the following error happen: $errStat" 3
+		} 
+		puts {<input type="hidden" name="action" value="updategrades"/>}
+		puts [concat <input type="hidden" name="columnname" value="$columnname"/>]
+		puts {<input type="submit" name="subaction" value="Submit" />}
+		puts {<input type="submit" name="subaction" value="Cancel" />}
+		puts {</form>}
+		puts {</div>}
+		puts {</div>}
+		#puts "<a href=\"$script_name\">Cancel changes</a>"
+		
+	} else {
+		htmlErrorMsg  "empty column names are not permitted"
+	}
+}
+
+proc getColListFromTable { table } {
+		set eval_str [concat SELECT * FROM \'$table\' ]
+		set err [catch {db eval $eval_str v {} } errStat]
+		set old_column_list $v(*)
+		return $old_column_list
+}
+
+proc removeElementFromList { element2remove old_list } {
+	set new_list {}
+	foreach element $old_list {
+		if { $element2remove ne $element } {
+			lappend new_list $element
+		}
+	}
+	return $new_list
+}
+
+proc colList2sqlColStr { col_list } {
+	set sqlStr {}
+	foreach col $col_list {
+		if {$sqlStr ne ""} {
+			set sqlStr $sqlStr,\"$col\"
+		} else {
+			set sqlStr \"$col\"
+		}
+	} 
+	return $sqlStr
+}
+	
+
+proc DeleteColumnNonWeb { columnname } {
+	if { $columnname != "" } {
+
+		# removing the column name to be deleted from total list
+
+		set old_column_list [getColListFromTable GradesTable]
+		set new_column_list [removeElementFromList $columnname $old_column_list]
+		set sql_new_column_str [colList2sqlColStr $new_column_list]
+		set eval_str "BEGIN TRANSACTION;
+			CREATE TEMPORARY TABLE GradesTable_backup($sql_new_column_str);
+			INSERT INTO GradesTable_backup SELECT $sql_new_column_str FROM GradesTable;
+			DROP TABLE GradesTable;
+			CREATE TABLE GradesTable($sql_new_column_str);
+			INSERT INTO GradesTable SELECT $sql_new_column_str FROM GradesTable_backup;
+			DROP TABLE GradesTable_backup;
+			COMMIT;"
+		set err [catch {db eval $eval_str  } errStat]
+		if { $err } {
+			htmlErrorMsg  $errStat 
+			dbg  "the following error happen: $errStat" 3
+		} 
+	} else {
+		htmlErrorMsg  "empty column names are not permitted"
+
+	}
+}
+
+proc DeleteColumn { permission_list user } {
+	global script_name
+	set columnname [::ncgi::value columnname {}]
+	DeleteColumnNonWeb $columnname
+}
+
+proc AddColumnNonWeb { columnname2add column_category maxpointpossible } {
+	if { $columnname2add != "" } {
+
+		set eval_str [concat ALTER TABLE GradesTable ADD \"$columnname2add\" text]
+		set err [catch {db eval $eval_str } errStat]
+		if { $err } {
+			htmlErrorMsg  $errStat 
+			dbg  "the following error happen: $errStat" 3
+		} 
+
+		UpdateColValue4UserNameNonWeb $columnname2add _Col_Category_ $column_category
+		UpdateColValue4UserNameNonWeb $columnname2add _Max_Points_   $maxpointpossible
+	} else {
+		htmlErrorMsg  "empty column names are not permitted"
+	}
+}
+
+proc AddColumn { permission_list user } { 
+	global script_name
+	set columnname2add [::ncgi::value columnname2add {}]
+	set column_category [::ncgi::value column_category {}]
+	set maxpointpossible [::ncgi::value maxpointpossible {}]
+	set columnname2add [ColName2SqlSafeForm $columnname2add]
+	AddColumnNonWeb  $columnname2add $column_category $maxpointpossible 
+}
+
+proc AddColumnRequest { permission_list user } { 
+	global script_name
+	puts {<div class="add_new_column">}
+	puts "<form name=\"input\"  method=\"post\" />"
+	puts {Column Name: <input type="text" name="columnname2add"><br>}
+	puts {Category: <select name="column_category">}
+	puts {<option value="unset">--Select--</option>}
+	puts {<option value="Quiz">Quiz</option>}
+	puts {<option value="HomeWork">HomeWork</option>}
+	puts {<option value="LabReport">LabReport</option>}
+	puts {<option value="MidTerm">MidTerm</option>}
+	puts {<option value="FinalExam">FinalExam</option>}
+	puts {</select> <br>}
+	puts {Max Point Possible:<input type="text" name="maxpointpossible"><br>}
+	puts {<input type="hidden" name="action" value="addcolumn"/>}
+	puts {<input type="submit" value="Submit" />}
+	puts {</form>}
+	puts {</div>}
+
+}
+
+proc ShowControls { permission_list user } {
+	array set permission $permission_list
+	global script_name
+	dbg "outputing contol list"
+	puts "<div class=\"controls\">"
+	set action_list [ list  defaultview "Refresh" addcolumnrequest "Add Column" logoff "Logoff" ]
+	set separator { }
+	foreach {act act_label} $action_list {
+		if { [isActionGranted $act $permission_list $user] } {
+			puts -nonewline "$separator<span class=\"controls\"><a href=$script_name?action=$act>$act_label</a></span>"
+		} 
+	}
+	puts "<br>"
+	# unhide user hidden columns actions
+	set currently_hidden_columns [SelectColValue4User UserHiddenColums $user]
+	if { $currently_hidden_columns ne "" } {
+		puts {Unhide columns: }
+		foreach col $currently_hidden_columns {
+			puts "<span class=\"controls\"><a href=\"$script_name?action=userunhidecolumn&columnname=[::ncgi::encode $col]\">$col</a></span>"
+		}
+	}
+	# hide user groups 
+	set user_groups_for_hide [list inforow student ta instructor]
+	set currently_hidden_groups [SelectColValue4User UserHiddenGroups $user]
+	# remove already hidden group from offering
+	foreach grp $currently_hidden_groups {
+		set user_groups_for_hide [removeElementFromList $grp $user_groups_for_hide]
+	}
+	# output group to hide offering
+	if { [isActionGranted userhidegroup $permission_list $user] } {
+		if { $user_groups_for_hide ne "" } {
+			puts "<br>"
+			puts "HideGroup: "
+			foreach grp $user_groups_for_hide {
+				puts "<span class=\"controls\"><a href=\"$script_name?action=userhidegroup&groupname=[::ncgi::encode $grp]\">$grp</a></span>"
+			}
+		}
+	}
+	if { [isActionGranted userunhidegroup $permission_list $user] } {
+		if { $currently_hidden_groups ne "" } {
+			puts "<br>"
+			puts {Unhide groups: }
+			foreach grp $currently_hidden_groups {
+				puts "<span class=\"controls\"><a href=\"$script_name?action=userunhidegroup&groupname=[::ncgi::encode $grp]\">$grp</a></span>"
+			}
+		}
+	}
+	
+	puts "</div>"	
+}
+
+proc AccessGroupRights {db  user password } {
+	dbg "access rights check for user: $user"
+	set PasswordHash [::md5::md5 -hex $password]
+	set eval_str [list SELECT GroupName FROM GradesTable WHERE UserName='$user' AND PasswordHash='$PasswordHash']
+	db eval $eval_str group_name_array {}
+	if { [ info exist group_name_array(GroupName) ] } {
+		set group $group_name_array(GroupName);
+	} else {
+		set group guest
+	}
+	dbg "Detected group is $group"
+	set eval_str [list SELECT actionname,$group FROM AccessRightsTable ]
+	set permission_list [list GroupName $group]
+	db eval $eval_str permissions { lappend permission_list $permissions(actionname) $permissions($group) }
+	dbg "permissions for user $user belonging to the group $group are: $permission_list"
+	return $permission_list
+}
+
+
+proc htmlGradesTable {db permission_list  user} {
+	array set permission $permission_list
+	global sortCol
+	switch $permission(GroupName) {
+		guest      { }
+		student         { htmlDBout db $permission_list $user $sortCol}
+		ta         { htmlDBout db $permission_list $user $sortCol}
+		instructor { htmlDBout db $permission_list $user $sortCol}
+		default    { }
+	}
+}
+
+proc htmlDefaultView { permission_list user } {
+	ChoseAction showcontrols $permission_list $user
+	ChoseAction showgrades $permission_list $user
+}
+
+proc htmlHeader {} {
+puts {
+<html xmlns="http://www.w3.org/1999/xhtml">
+<head>
+	<meta http-equiv="Content-Type" content= "text/html; charset=us-ascii" />
+	<title>Grade Book</title>
+	<link rel="stylesheet" type="text/css" href="/~evmik/GradeBook.css" />
+</head>
+}
+}
+
+
+##################### end of procs ####################################
+
+# vim: ts=2 sw=2 foldmethod=indent: