--- loncom/interface/lonhelper.pm 2003/03/21 18:11:11 1.1
+++ loncom/interface/lonhelper.pm 2003/04/10 18:02:09 1.5
@@ -1,7 +1,7 @@
# The LearningOnline Network with CAPA
# .helper XML handler to implement the LON-CAPA helper
#
-# $Id: lonhelper.pm,v 1.1 2003/03/21 18:11:11 bowersj2 Exp $
+# $Id: lonhelper.pm,v 1.5 2003/04/10 18:02:09 bowersj2 Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -30,8 +30,1607 @@
# (.helper handler
#
+# FIXME: Change register calls to register with the helper.
+# Then have the helper reg and unreg the tags.
+# This removes my concerns about breaking other code.
+
+=pod
+
+=head1 lonhelper - HTML Helper framework for LON-CAPA
+
+Helpers, often known as "wizards", are well-established UI widgets that users
+feel comfortable with. It can take a complicated multidimensional problem the
+user has and turn it into a series of bite-sized one-dimensional questions.
+
+For developers, helpers provide an easy way to bundle little bits of functionality
+for the user, without having to write the tedious state-maintenence code.
+
+Helpers are defined as XML documents, placed in the /home/httpd/html/adm/helpers
+directory and having the .helper file extension. For examples, see that directory.
+
+All classes are in the Apache::lonhelper namespace.
+
+=head2 lonhelper XML file format
+
+A helper consists of a top-level <helper> tag which contains a series of states.
+Each state contains one or more state elements, which are what the user sees, like
+messages, resource selections, or date queries.
+
+The helper tag is required to have one attribute, "title", which is the name
+of the helper itself, such as "Parameter helper".
+
+=head2 State tags
+
+State tags are required to have an attribute "name", which is the symbolic
+name of the state and will not be directly seen by the user. The wizard is
+required to have one state named "START", which is the state the wizard
+will start with. By convention, this state should clearly describe what
+the helper will do for the user, and may also include the first information
+entry the user needs to do for the helper.
+
+State tags are also required to have an attribute "title", which is the
+human name of the state, and will be displayed as the header on top of
+the screen for the user.
+
+=head2 Example Helper Skeleton
+
+An example of the tags so far:
+
+ <helper title="Example Helper">
+ <state name="START" title="Demonstrating the Example Helper">
+ <!-- notice this is the START state the wizard requires -->
+ </state>
+ <state name="GET_NAME" title="Enter Student Name">
+ </state>
+ </helper>
+
+Of course this does nothing. In order for the wizard to do something, it is
+necessary to put actual elements into the wizard. Documentation for each
+of these elements follows.
+
+=cut
+
package Apache::lonhelper;
+use Apache::Constants qw(:common);
+use Apache::File;
+use Apache::lonxml;
+
+BEGIN {
+ &Apache::lonxml::register('Apache::lonhelper',
+ ('helper', 'state'));
+}
+
+# Since all wizards are only three levels deep (wizard tag, state tag,
+# substate type), it's easier and more readble to explicitly track
+# those three things directly, rather then futz with the tag stack
+# every time.
+my $helper;
+my $state;
+my $substate;
+# To collect parameters, the contents of the subtags are collected
+# into this paramHash, then passed to the element object when the
+# end of the element tag is located.
+my $paramHash;
+
+sub handler {
+ my $r = shift;
+ $ENV{'request.uri'} = $r->uri();
+ my $filename = '/home/httpd/html' . $r->uri();
+ my $fh = Apache::File->new($filename);
+ my $file;
+ read $fh, $file, 100000000;
+
+ Apache::loncommon::get_unprocessed_cgi($ENV{QUERY_STRING});
+
+ # Send header, don't cache this page
+ if ($r->header_only) {
+ if ($ENV{'browser.mathml'}) {
+ $r->content_type('text/xml');
+ } else {
+ $r->content_type('text/html');
+ }
+ $r->send_http_header;
+ return OK;
+ }
+ if ($ENV{'browser.mathml'}) {
+ $r->content_type('text/xml');
+ } else {
+ $r->content_type('text/html');
+ }
+ $r->send_http_header;
+ $r->rflush();
+
+ # Discard result, we just want the objects that get created by the
+ # xml parsing
+ &Apache::lonxml::xmlparse($r, 'helper', $file);
+
+ $r->print($helper->display());
+ return OK;
+}
+
+sub start_helper {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ $helper = Apache::lonhelper::helper->new($token->[2]{'title'});
+ return '';
+}
+
+sub end_helper {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ return '';
+}
+
+sub start_state {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ $state = Apache::lonhelper::state->new($token->[2]{'name'},
+ $token->[2]{'title'});
+ return '';
+}
+
+# don't need this, so ignore it
+sub end_state {
+ return '';
+}
+
+1;
+
+package Apache::lonhelper::helper;
+
+use Digest::MD5 qw(md5_hex);
+use HTML::Entities;
+use Apache::loncommon;
+use Apache::File;
+
+sub new {
+ my $proto = shift;
+ my $class = ref($proto) || $proto;
+ my $self = {};
+
+ $self->{TITLE} = shift;
+
+ # If there is a state from the previous form, use that. If there is no
+ # state, use the start state parameter.
+ if (defined $ENV{"form.CURRENT_STATE"})
+ {
+ $self->{STATE} = $ENV{"form.CURRENT_STATE"};
+ }
+ else
+ {
+ $self->{STATE} = "START";
+ }
+
+ $self->{TOKEN} = $ENV{'form.TOKEN'};
+ # If a token was passed, we load that in. Otherwise, we need to create a
+ # new storage file
+ # Tried to use standard Tie'd hashes, but you can't seem to take a
+ # reference to a tied hash and write to it. I'd call that a wart.
+ if ($self->{TOKEN}) {
+ # Validate the token before trusting it
+ if ($self->{TOKEN} !~ /^[a-f0-9]{32}$/) {
+ # Not legit. Return nothing and let all hell break loose.
+ # User shouldn't be doing that!
+ return undef;
+ }
+
+ # Get the hash.
+ $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN}); # Note the token is not the literal file
+
+ my $file = Apache::File->new($self->{FILENAME});
+ my $contents = <$file>;
+
+ # Now load in the contents
+ for my $value (split (/&/, $contents)) {
+ my ($name, $value) = split(/=/, $value);
+ $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
+ $self->{VARS}->{$name} = $value;
+ }
+
+ $file->close();
+ } else {
+ # Only valid if we're just starting.
+ if ($self->{STATE} ne 'START') {
+ return undef;
+ }
+ # Must create the storage
+ $self->{TOKEN} = md5_hex($ENV{'user.name'} . $ENV{'user.domain'} .
+ time() . rand());
+ $self->{FILENAME} = $Apache::lonnet::tmpdir . md5_hex($self->{TOKEN});
+ }
+
+ # OK, we now have our persistent storage.
+
+ if (defined $ENV{"form.RETURN_PAGE"})
+ {
+ $self->{RETURN_PAGE} = $ENV{"form.RETURN_PAGE"};
+ }
+ else
+ {
+ $self->{RETURN_PAGE} = $ENV{REFERER};
+ }
+
+ $self->{STATES} = {};
+ $self->{DONE} = 0;
+
+ bless($self, $class);
+ return $self;
+}
+
+# Private function; returns a string to construct the hidden fields
+# necessary to have the helper track state.
+sub _saveVars {
+ my $self = shift;
+ my $result = "";
+ $result .= '<input type="hidden" name="CURRENT_STATE" value="' .
+ HTML::Entities::encode($self->{STATE}) . "\" />\n";
+ $result .= '<input type="hidden" name="TOKEN" value="' .
+ $self->{TOKEN} . "\" />\n";
+ $result .= '<input type="hidden" name="RETURN_PAGE" value="' .
+ HTML::Entities::encode($self->{RETURN_PAGE}) . "\" />\n";
+
+ return $result;
+}
+
+# Private function: Create the querystring-like representation of the stored
+# data to write to disk.
+sub _varsInFile {
+ my $self = shift;
+ my @vars = ();
+ for my $key (keys %{$self->{VARS}}) {
+ push @vars, &Apache::lonnet::escape($key) . '=' .
+ &Apache::lonnet::escape($self->{VARS}->{$key});
+ }
+ return join ('&', @vars);
+}
+
+# Use this to declare variables.
+# FIXME: Document this
+sub declareVar {
+ my $self = shift;
+ my $var = shift;
+
+ if (!defined($self->{VARS}->{$var})) {
+ $self->{VARS}->{$var} = '';
+ }
+
+ my $envname = 'form.' . $var . '.forminput';
+ if (defined($ENV{$envname})) {
+ $self->{VARS}->{$var} = $ENV{$envname};
+ }
+}
+
+sub changeState {
+ my $self = shift;
+ $self->{STATE} = shift;
+}
+
+sub registerState {
+ my $self = shift;
+ my $state = shift;
+
+ my $stateName = $state->name();
+ $self->{STATES}{$stateName} = $state;
+}
+
+# Done in four phases
+# 1: Do the post processing for the previous state.
+# 2: Do the preprocessing for the current state.
+# 3: Check to see if state changed, if so, postprocess current and move to next.
+# Repeat until state stays stable.
+# 4: Render the current state to the screen as an HTML page.
+sub display {
+ my $self = shift;
+
+ my $result = "";
+
+ # Phase 1: Post processing for state of previous screen (which is actually
+ # the "current state" in terms of the helper variables), if it wasn't the
+ # beginning state.
+ if ($self->{STATE} ne "START" || $ENV{"form.SUBMIT"} eq "Next ->") {
+ my $prevState = $self->{STATES}{$self->{STATE}};
+ $prevState->postprocess();
+ }
+
+ # Note, to handle errors in a state's input that a user must correct,
+ # do not transition in the postprocess, and force the user to correct
+ # the error.
+
+ # Phase 2: Preprocess current state
+ my $startState = $self->{STATE};
+ my $state = $self->{STATES}{$startState};
+
+ # Error checking; it is intended that the developer will have
+ # checked all paths and the user can't see this!
+ if (!defined($state)) {
+ $result .="Error! The state ". $startState ." is not defined.";
+ return $result;
+ }
+ $state->preprocess();
+
+ # Phase 3: While the current state is different from the previous state,
+ # keep processing.
+ while ( $startState ne $self->{STATE} )
+ {
+ $startState = $self->{STATE};
+ $state = $self->{STATES}{$startState};
+ $state->preprocess();
+ }
+
+ # Phase 4: Display.
+ my $stateTitle = $state->title();
+ my $bodytag = &Apache::loncommon::bodytag("$self->{TITLE}",'','');
+
+ $result .= <<HEADER;
+<html>
+ <head>
+ <title>LON-CAPA Helper: $self->{TITLE}</title>
+ </head>
+ $bodytag
+HEADER
+ if (!$state->overrideForm()) { $result.="<form name='wizform' method='GET'>"; }
+ $result .= <<HEADER;
+ <table border="0"><tr><td>
+ <h2><i>$stateTitle</i></h2>
+HEADER
+
+ if (!$state->overrideForm()) {
+ $result .= $self->_saveVars();
+ }
+ $result .= $state->render() . "<p> </p>";
+
+ if (!$state->overrideForm()) {
+ $result .= '<center>';
+ if ($self->{STATE} ne $self->{START_STATE}) {
+ #$result .= '<input name="SUBMIT" type="submit" value="<- Previous" /> ';
+ }
+ if ($self->{DONE}) {
+ my $returnPage = $self->{RETURN_PAGE};
+ $result .= "<a href=\"$returnPage\">End Helper</a>";
+ }
+ else {
+ $result .= '<input name="back" type="button" ';
+ $result .= 'value="<- Previous" onclick="history.go(-1)" /> ';
+ $result .= '<input name="SUBMIT" type="submit" value="Next ->" />';
+ }
+ $result .= "</center>\n";
+ }
+
+ foreach my $key (keys %{$self->{VARS}}) {
+ $result .= "|$key| -> " . $self->{VARS}->{$key} . "<br />";
+ }
+
+ $result .= <<FOOTER;
+ </td>
+ </tr>
+ </table>
+ </form>
+ </body>
+</html>
+FOOTER
+
+ # Handle writing out the vars to the file
+ my $file = Apache::File->new('>'.$self->{FILENAME});
+ print $file $self->_varsInFile();
+
+ return $result;
+}
+
+1;
+
+package Apache::lonhelper::state;
+
+# States bundle things together and are responsible for compositing the
+# various elements together. It is not generally necessary for users to
+# use the state object directly, so it is not perldoc'ed.
+
+# Basically, all the states do is pass calls to the elements and aggregate
+# the results.
+
+sub new {
+ my $proto = shift;
+ my $class = ref($proto) || $proto;
+ my $self = {};
+
+ $self->{NAME} = shift;
+ $self->{TITLE} = shift;
+ $self->{ELEMENTS} = [];
+
+ bless($self, $class);
+
+ $helper->registerState($self);
+
+ return $self;
+}
+
+sub name {
+ my $self = shift;
+ return $self->{NAME};
+}
+
+sub title {
+ my $self = shift;
+ return $self->{TITLE};
+}
+
+sub preprocess {
+ my $self = shift;
+ for my $element (@{$self->{ELEMENTS}}) {
+ $element->preprocess();
+ }
+}
+
+sub postprocess {
+ my $self = shift;
+
+ for my $element (@{$self->{ELEMENTS}}) {
+ $element->postprocess();
+ }
+}
+
+sub overrideForm {
+ return 0;
+}
+
+sub addElement {
+ my $self = shift;
+ my $element = shift;
+
+ push @{$self->{ELEMENTS}}, $element;
+}
+
+sub render {
+ my $self = shift;
+ my @results = ();
+
+ for my $element (@{$self->{ELEMENTS}}) {
+ push @results, $element->render();
+ }
+ return join("\n", @results);
+}
+
+1;
+
+package Apache::lonhelper::element;
+# Support code for elements
+
+=pod
+
+=head2 Element Base Class
+
+The Apache::lonhelper::element base class provides support methods for
+the elements to use, such as a multiple value processer.
+
+B<Methods>:
+
+=over 4
+
+=item * process_multiple_choices(formName, varName): Process the form
+element named "formName" and place the selected items into the helper
+variable named varName. This is for things like checkboxes or
+multiple-selection listboxes where the user can select more then
+one entry. The selected entries are delimited by triple pipes in
+the helper variables, like this:
+
+ CHOICE_1|||CHOICE_2|||CHOICE_3
+
+=back
+
+=cut
+
+BEGIN {
+ &Apache::lonxml::register('Apache::lonhelper::element',
+ ('nextstate'));
+}
+
+# Because we use the param hash, this is often a sufficent
+# constructor
+sub new {
+ my $proto = shift;
+ my $class = ref($proto) || $proto;
+ my $self = $paramHash;
+ bless($self, $class);
+
+ $self->{PARAMS} = $paramHash;
+ $self->{STATE} = $state;
+ $state->addElement($self);
+
+ # Ensure param hash is not reused
+ $paramHash = {};
+
+ return $self;
+}
+
+sub start_nextstate {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ $paramHash->{NEXTSTATE} = &Apache::lonxml::get_all_text('/nextstate',
+ $parser);
+ return '';
+}
+
+sub end_nextstate { return ''; }
+
+sub preprocess {
+ return 1;
+}
+
+sub postprocess {
+ return 1;
+}
+
+sub render {
+ return '';
+}
+
+sub process_multiple_choices {
+ my $self = shift;
+ my $formname = shift;
+ my $var = shift;
+
+ my $formvalue = $ENV{'form.' . $formname};
+ if ($formvalue) {
+ # Must extract values from querystring directly, as there
+ # may be more then one.
+ my @values;
+ for my $formparam (split (/&/, $ENV{QUERY_STRING})) {
+ my ($name, $value) = split(/=/, $formparam);
+ if ($name ne $formname) {
+ next;
+ }
+ $value =~ tr/+/ /;
+ $value =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
+ push @values, $value;
+ }
+ $helper->{VARS}->{$var} = join('|||', @values);
+ }
+
+ return;
+}
+
+1;
+
+package Apache::lonhelper::message;
+
+=pod
+
+=head2 Element: message
+
+Message elements display the contents of their <message_text> tags, and
+transition directly to the state in the <nextstate> tag. Example:
+
+ <message>
+ <nextstate>GET_NAME</nextstate>
+ <message_text>This is the <b>message</b> the user will see,
+ <i>HTML allowed</i>.</message_text>
+ </message>
+
+This will display the HTML message and transition to the <nextstate> if
+given. The HTML will be directly inserted into the wizard, so if you don't
+want text to run together, you'll need to manually wrap the <message_text>
+in <p> tags, or whatever is appropriate for your HTML.
+
+Message tags do not add in whitespace, so if you want it, you'll need to add
+it into states. This is done so you can inline some elements, such as
+the <date> element, right between two messages, giving the appearence that
+the <date> element appears inline. (Note the elements can not be embedded
+within each other.)
+
+This is also a good template for creating your own new states, as it has
+very little code beyond the state template.
+
+=cut
+
+no strict;
+@ISA = ("Apache::lonhelper::element");
+use strict;
+
+BEGIN {
+ &Apache::lonxml::register('Apache::lonhelper::message',
+ ('message', 'message_text'));
+}
+
+sub new {
+ my $ref = Apache::lonhelper::element->new();
+ bless($ref);
+}
+
+# CONSTRUCTION: Construct the message element from the XML
+sub start_message {
+ return '';
+}
+
+sub end_message {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+ Apache::lonhelper::message->new();
+ return '';
+}
+
+sub start_message_text {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ $paramHash->{MESSAGE_TEXT} = &Apache::lonxml::get_all_text('/message_text',
+ $parser);
+}
+
+sub end_message_text { return 1; }
+
+sub render {
+ my $self = shift;
+
+ return $self->{MESSAGE_TEXT};
+}
+# If a NEXTSTATE was given, switch to it
+sub postprocess {
+ my $self = shift;
+ if (defined($self->{NEXTSTATE})) {
+ $helper->changeState($self->{NEXTSTATE});
+ }
+}
+1;
+
+package Apache::lonhelper::choices;
+
+=pod
+
+=head2 Element: choices
+
+Choice states provide a single choice to the user as a text selection box.
+A "choice" is two pieces of text, one which will be displayed to the user
+(the "human" value), and one which will be passed back to the program
+(the "computer" value). For instance, a human may choose from a list of
+resources on disk by title, while your program wants the file name.
+
+<choices> takes an attribute "variable" to control which helper variable
+the result is stored in.
+
+<choices> takes an attribute "multichoice" which, if set to a true
+value, will allow the user to select multiple choices.
+
+B<SUB-TAGS>
+
+<choices> can have the following subtags:
+
+=over 4
+
+=item * <nextstate>state_name</nextstate>: If given, this will cause the
+ choice element to transition to the given state after executing. If
+ this is used, do not pass nextstates to the <choice> tag.
+
+=item * <choice />: If the choices are static,
+ this element will allow you to specify them. Each choice
+ contains attribute, "computer", as described above. The
+ content of the tag will be used as the human label.
+ For example,
+ <choice computer='234-12-7312'>Bobby McDormik</choice>.
+
+<choice> may optionally contain a 'nextstate' attribute, which
+will be the state transisitoned to if the choice is made, if
+the choice is not multichoice.
+
+=back
+
+To create the choices programmatically, either wrap the choices in
+<condition> tags (prefered), or use an <exec> block inside the <choice>
+tag. Store the choices in $state->{CHOICES}, which is a list of list
+references, where each list has three strings. The first is the human
+name, the second is the computer name. and the third is the option
+next state. For example:
+
+ <exec>
+ for (my $i = 65; $i < 65 + 26; $i++) {
+ push @{$state->{CHOICES}}, [chr($i), $i, 'next'];
+ }
+ </exec>
+
+This will allow the user to select from the letters A-Z (in ASCII), while
+passing the ASCII value back into the helper variables, and the state
+will in all cases transition to 'next'.
+
+You can mix and match methods of creating choices, as long as you always
+"push" onto the choice list, rather then wiping it out. (You can even
+remove choices programmatically, but that would probably be bad form.)
+
+FIXME: Document and implement <exec> and <condition> in the element package.
+
+=cut
+
+no strict;
+@ISA = ("Apache::lonhelper::element");
+use strict;
+
+BEGIN {
+ &Apache::lonxml::register('Apache::lonhelper::choices',
+ ('choice', 'choices'));
+}
+
+sub new {
+ my $ref = Apache::lonhelper::element->new();
+ bless($ref);
+}
+
+# CONSTRUCTION: Construct the message element from the XML
+sub start_choices {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ # Need to initialize the choices list, so everything can assume it exists
+ $paramHash->{'variable'} = $token->[2]{'variable'};
+ $helper->declareVar($paramHash->{'variable'});
+ $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
+ $paramHash->{CHOICES} = [];
+ return '';
+}
+
+sub end_choices {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+ Apache::lonhelper::choices->new();
+ return '';
+}
+
+sub start_choice {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ my $computer = $token->[2]{'computer'};
+ my $human = &Apache::lonxml::get_all_text('/choice',
+ $parser);
+ my $nextstate = $token->[2]{'nextstate'};
+ push @{$paramHash->{CHOICES}}, [$human, $computer, $nextstate];
+ return '';
+}
+
+sub end_choice {
+ return '';
+}
+
+sub render {
+ # START HERE: Replace this with correct choices code.
+ my $self = shift;
+ my $var = $self->{'variable'};
+ my $buttons = '';
+ my $result = '';
+
+ if ($self->{'multichoice'}) {
+ $result = <<SCRIPT;
+<script>
+ function checkall(value) {
+ for (i=0; i<document.forms.wizform.elements.length; i++) {
+ document.forms.wizform.elements[i].checked=value;
+ }
+ }
+</script>
+SCRIPT
+ $buttons = <<BUTTONS;
+<br />
+<input type="button" onclick="checkall(true)" value="Select All" />
+<input type="button" onclick="checkall(false)" value="Unselect All" />
+<br />
+BUTTONS
+ }
+
+ if (defined $self->{ERROR_MSG}) {
+ $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
+ }
+
+ $result .= $buttons;
+
+ $result .= "<table>\n\n";
+
+ my $type = "radio";
+ if ($self->{'multichoice'}) { $type = 'checkbox'; }
+ my $checked = 0;
+ foreach my $choice (@{$self->{CHOICES}}) {
+ $result .= "<tr>\n<td width='20'> </td>\n";
+ $result .= "<td valign='top'><input type='$type' name='$var.forminput'"
+ . "' value='" .
+ HTML::Entities::encode($choice->[1])
+ . "'";
+ if (!$self->{'multichoice'} && !$checked) {
+ $result .= " checked ";
+ $checked = 1;
+ }
+ $result .= "/></td><td> " . $choice->[0] . "</td></tr>\n";
+ }
+ $result .= "</table>\n\n\n";
+ $result .= $buttons;
+
+ return $result;
+}
+
+# If a NEXTSTATE was given or a nextstate for this choice was
+# given, switch to it
+sub postprocess {
+ my $self = shift;
+ my $chosenValue = $ENV{'form.' . $self->{'variable'} . '.forminput'};
+
+ if (defined($self->{NEXTSTATE})) {
+ $helper->changeState($self->{NEXTSTATE});
+ }
+
+ foreach my $choice (@{$self->{CHOICES}}) {
+ if ($choice->[1] eq $chosenValue) {
+ if (defined($choice->[2])) {
+ $helper->changeState($choice->[2]);
+ }
+ }
+ }
+}
+1;
+
+package Apache::lonhelper::date;
+
+=pod
+
+=head2 Element: date
+
+Date elements allow the selection of a date with a drop down list.
+
+Date elements can take two attributes:
+
+=over 4
+
+=item * B<variable>: The name of the variable to store the chosen
+ date in. Required.
+
+=item * B<hoursminutes>: If a true value, the date will show hours
+ and minutes, as well as month/day/year. If false or missing,
+ the date will only show the month, day, and year.
+
+=back
+
+Date elements contain only an option <nextstate> tag to determine
+the next state.
+
+Example:
+
+ <date variable="DUE_DATE" hoursminutes="1">
+ <nextstate>choose_why</nextstate>
+ </date>
+
+=cut
+
+no strict;
+@ISA = ("Apache::lonhelper::element");
+use strict;
+
+use Time::localtime;
+
+BEGIN {
+ &Apache::lonxml::register('Apache::lonhelper::date',
+ ('date'));
+}
+
+# Don't need to override the "new" from element
+sub new {
+ my $ref = Apache::lonhelper::element->new();
+ bless($ref);
+}
+
+my @months = ("January", "February", "March", "April", "May", "June", "July",
+ "August", "September", "October", "November", "December");
+
+# CONSTRUCTION: Construct the message element from the XML
+sub start_date {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ $paramHash->{'variable'} = $token->[2]{'variable'};
+ $helper->declareVar($paramHash->{'variable'});
+ $paramHash->{'hoursminutes'} = $token->[2]{'hoursminutes'};
+}
+
+sub end_date {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+ Apache::lonhelper::date->new();
+ return '';
+}
+
+sub render {
+ my $self = shift;
+ my $result = "";
+ my $var = $self->{'variable'};
+
+ my $date;
+
+ # Default date: The current hour.
+ $date = localtime();
+ $date->min(0);
+
+ if (defined $self->{ERROR_MSG}) {
+ $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
+ }
+
+ # Month
+ my $i;
+ $result .= "<select name='${var}month'>\n";
+ for ($i = 0; $i < 12; $i++) {
+ if ($i == $date->mon) {
+ $result .= "<option value='$i' selected>";
+ } else {
+ $result .= "<option value='$i'>";
+ }
+ $result .= $months[$i] . "</option>\n";
+ }
+ $result .= "</select>\n";
+
+ # Day
+ $result .= "<select name='${var}day'>\n";
+ for ($i = 1; $i < 32; $i++) {
+ if ($i == $date->mday) {
+ $result .= '<option selected>';
+ } else {
+ $result .= '<option>';
+ }
+ $result .= "$i</option>\n";
+ }
+ $result .= "</select>,\n";
+
+ # Year
+ $result .= "<select name='${var}year'>\n";
+ for ($i = 2000; $i < 2030; $i++) { # update this after 64-bit dates
+ if ($date->year + 1900 == $i) {
+ $result .= "<option selected>";
+ } else {
+ $result .= "<option>";
+ }
+ $result .= "$i</option>\n";
+ }
+ $result .= "</select>,\n";
+
+ # Display Hours and Minutes if they are called for
+ if ($self->{'hoursminutes'}) {
+ # Build hour
+ $result .= "<select name='${var}hour'>\n";
+ $result .= "<option " . ($date->hour == 0 ? 'selected ':'') .
+ " value='0'>midnight</option>\n";
+ for ($i = 1; $i < 12; $i++) {
+ if ($date->hour == $i) {
+ $result .= "<option selected value='$i'>$i a.m.</option>\n";
+ } else {
+ $result .= "<option value='$i'>$i a.m</option>\n";
+ }
+ }
+ $result .= "<option " . ($date->hour == 12 ? 'selected ':'') .
+ " value='12'>noon</option>\n";
+ for ($i = 13; $i < 24; $i++) {
+ my $printedHour = $i - 12;
+ if ($date->hour == $i) {
+ $result .= "<option selected value='$i'>$printedHour p.m.</option>\n";
+ } else {
+ $result .= "<option value='$i'>$printedHour p.m.</option>\n";
+ }
+ }
+
+ $result .= "</select> :\n";
+
+ $result .= "<select name='${var}minute'>\n";
+ for ($i = 0; $i < 60; $i++) {
+ my $printedMinute = $i;
+ if ($i < 10) {
+ $printedMinute = "0" . $printedMinute;
+ }
+ if ($date->min == $i) {
+ $result .= "<option selected>";
+ } else {
+ $result .= "<option>";
+ }
+ $result .= "$printedMinute</option>\n";
+ }
+ $result .= "</select>\n";
+ }
+
+ return $result;
+
+}
+# If a NEXTSTATE was given, switch to it
+sub postprocess {
+ my $self = shift;
+ my $var = $self->{'variable'};
+ my $month = $ENV{'form.' . $var . 'month'};
+ my $day = $ENV{'form.' . $var . 'day'};
+ my $year = $ENV{'form.' . $var . 'year'};
+ my $min = 0;
+ my $hour = 0;
+ if ($self->{'hoursminutes'}) {
+ $min = $ENV{'form.' . $var . 'minute'};
+ $hour = $ENV{'form.' . $var . 'hour'};
+ }
+
+ my $chosenDate = Time::Local::timelocal(0, $min, $hour, $day, $month, $year);
+ # Check to make sure that the date was not automatically co-erced into a
+ # valid date, as we want to flag that as an error
+ # This happens for "Feb. 31", for instance, which is coerced to March 2 or
+ # 3, depending on if it's a leapyear
+ my $checkDate = localtime($chosenDate);
+
+ if ($checkDate->mon != $month || $checkDate->mday != $day ||
+ $checkDate->year + 1900 != $year) {
+ $self->{ERROR_MSG} = "Can't use " . $months[$month] . " $day, $year as a "
+ . "date because it doesn't exist. Please enter a valid date.";
+ return;
+ }
+
+ $helper->{VARS}->{$var} = $chosenDate;
+
+ if (defined($self->{NEXTSTATE})) {
+ $helper->changeState($self->{NEXTSTATE});
+ }
+}
+1;
+
+package Apache::lonhelper::resource;
+
+=pod
+
+=head2 Element: resource
+
+<resource> elements allow the user to select one or multiple resources
+from the current course. You can filter out which resources they can view,
+and filter out which resources they can select. The course will always
+be displayed fully expanded, because of the difficulty of maintaining
+selections across folder openings and closings. If this is fixed, then
+the user can manipulate the folders.
+
+<resource> takes the standard variable attribute to control what helper
+variable stores the results. It also takes a "multichoice" attribute,
+which controls whether the user can select more then one resource.
+
+B<SUB-TAGS>
+
+=over 4
+
+=item * <filterfunc>: If you want to filter what resources are displayed
+ to the user, use a filter func. The <filterfunc> tag should contain
+ Perl code that when wrapped with "sub { my $res = shift; " and "}" is
+ a function that returns true if the resource should be displayed,
+ and false if it should be skipped. $res is a resource object.
+ (See Apache::lonnavmaps documentation for information about the
+ resource object.)
+
+=item * <choicefunc>: Same as <filterfunc>, except that controls whether
+ the given resource can be chosen. (It is almost always a good idea to
+ show the user the folders, for instance, but you do not always want to
+ let the user select them.)
+
+=item * <nextstate>: Standard nextstate behavior.
+
+=item * <valuefunc>: This function controls what is returned by the resource
+ when the user selects it. Like filterfunc and choicefunc, it should be
+ a function fragment that when wrapped by "sub { my $res = shift; " and
+ "}" returns a string representing what you want to have as the value. By
+ default, the value will be the resource ID of the object ($res->{ID}).
+
+=back
+
+=cut
+
+no strict;
+@ISA = ("Apache::lonhelper::element");
+use strict;
+
+BEGIN {
+ &Apache::lonxml::register('Apache::lonhelper::resource',
+ ('resource', 'filterfunc',
+ 'choicefunc', 'valuefunc'));
+}
+
+sub new {
+ my $ref = Apache::lonhelper::element->new();
+ bless($ref);
+}
+
+# CONSTRUCTION: Construct the message element from the XML
+sub start_resource {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ $paramHash->{'variable'} = $token->[2]{'variable'};
+ $helper->declareVar($paramHash->{'variable'});
+ return '';
+}
+
+sub end_resource {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+ if (!defined($paramHash->{FILTER_FUNC})) {
+ $paramHash->{FILTER_FUNC} = sub {return 1;};
+ }
+ if (!defined($paramHash->{CHOICE_FUNC})) {
+ $paramHash->{CHOICE_FUNC} = sub {return 1;};
+ }
+ if (!defined($paramHash->{VALUE_FUNC})) {
+ $paramHash->{VALUE_FUNC} = sub {my $res = shift; return $res->{ID}; };
+ }
+ Apache::lonhelper::resource->new();
+ return '';
+}
+
+sub start_filterfunc {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ my $contents = Apache::lonxml::get_all_text('/filterfunc',
+ $parser);
+ $contents = 'sub { my $res = shift; ' . $contents . '}';
+ $paramHash->{FILTER_FUNC} = eval $contents;
+}
+
+sub end_filterfunc { return ''; }
+
+sub start_choicefunc {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ my $contents = Apache::lonxml::get_all_text('/choicefunc',
+ $parser);
+ $contents = 'sub { my $res = shift; ' . $contents . '}';
+ $paramHash->{CHOICE_FUNC} = eval $contents;
+}
+
+sub end_choicefunc { return ''; }
+
+sub start_valuefunc {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ my $contents = Apache::lonxml::get_all_text('/valuefunc',
+ $parser);
+ $contents = 'sub { my $res = shift; ' . $contents . '}';
+ $paramHash->{VALUE_FUNC} = eval $contents;
+}
+
+sub end_valuefunc { return ''; }
+
+# A note, in case I don't get to this before I leave.
+# If someone complains about the "Back" button returning them
+# to the previous folder state, instead of returning them to
+# the previous helper state, the *correct* answer is for the helper
+# to keep track of how many times the user has manipulated the folders,
+# and feed that to the history.go() call in the helper rendering routines.
+# If done correctly, the helper itself can keep track of how many times
+# it renders the same states, so it doesn't go in just this state, and
+# you can lean on the browser back button to make sure it all chains
+# correctly.
+# Right now, though, I'm just forcing all folders open.
+
+sub render {
+ my $self = shift;
+ my $result = "";
+ my $var = $self->{'variable'};
+ my $curVal = $helper->{VARS}->{$var};
+
+ if (defined $self->{ERROR_MSG}) {
+ $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
+ }
+
+ my $filterFunc = $self->{FILTER_FUNC};
+ my $choiceFunc = $self->{CHOICE_FUNC};
+ my $valueFunc = $self->{VALUE_FUNC};
+
+ # Create the composite function that renders the column on the nav map
+ # have to admit any language that lets me do this can't be all bad
+ # - Jeremy (Pythonista) ;-)
+ my $checked = 0;
+ my $renderColFunc = sub {
+ my ($resource, $part, $params) = @_;
+
+ if (!&$choiceFunc($resource)) {
+ return '<td> </td>';
+ } else {
+ my $col = "<td><input type='radio' name='${var}.forminput' ";
+ if (!$checked) {
+ $col .= "checked ";
+ $checked = 1;
+ }
+ $col .= "value='" .
+ HTML::Entities::encode(&$valueFunc($resource))
+ . "' /></td>";
+ return $col;
+ }
+ };
+
+ $ENV{'form.condition'} = 1;
+ $result .=
+ &Apache::lonnavmaps::render( { 'cols' => [$renderColFunc,
+ Apache::lonnavmaps::resource()],
+ 'showParts' => 0,
+ 'url' => $helper->{URL},
+ 'filterFunc' => $filterFunc,
+ 'resource_no_folder_link' => 1 }
+ );
+
+ return $result;
+}
+
+sub postprocess {
+ my $self = shift;
+ if (defined($self->{NEXTSTATE})) {
+ $helper->changeState($self->{NEXTSTATE});
+ }
+}
+
+1;
+
+package Apache::lonhelper::student;
+
+=pod
+
+=head2 Element: student
+
+Student elements display a choice of students enrolled in the current
+course. Currently it is primitive; this is expected to evolve later.
+
+Student elements take two attributes: "variable", which means what
+it usually does, and "multichoice", which if true allows the user
+to select multiple students.
+
+=cut
+
+no strict;
+@ISA = ("Apache::lonhelper::element");
+use strict;
+
+
+
+BEGIN {
+ &Apache::lonxml::register('Apache::lonhelper::student',
+ ('student'));
+}
+
+sub new {
+ my $ref = Apache::lonhelper::element->new();
+ bless($ref);
+}
+
+sub start_student {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ $paramHash->{'variable'} = $token->[2]{'variable'};
+ $helper->declareVar($paramHash->{'variable'});
+ $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
+}
+
+sub end_student {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+ Apache::lonhelper::student->new();
+}
+
+sub render {
+ my $self = shift;
+ my $result = '';
+ my $buttons = '';
+
+ if ($self->{'multichoice'}) {
+ $result = <<SCRIPT;
+<script>
+ function checkall(value) {
+ for (i=0; i<document.forms.wizform.elements.length; i++) {
+ document.forms.wizform.elements[i].checked=value;
+ }
+ }
+</script>
+SCRIPT
+ $buttons = <<BUTTONS;
+<br />
+<input type="button" onclick="checkall(true)" value="Select All" />
+<input type="button" onclick="checkall(false)" value="Unselect All" />
+<br />
+BUTTONS
+ }
+
+ if (defined $self->{ERROR_MSG}) {
+ $result .= '<font color="#FF0000">' . $self->{ERROR_MSG} . '</font><br /><br />';
+ }
+
+ # Load up the students
+ my $choices = &Apache::loncoursedata::get_classlist();
+
+ my @keys = keys %{$choices};
+
+ # Constants
+ my $section = Apache::loncoursedata::CL_SECTION();
+ my $fullname = Apache::loncoursedata::CL_FULLNAME();
+
+ # Sort by: Section, name
+ @keys = sort {
+ if ($choices->{$a}->[$section] ne $choices->{$b}->[$section]) {
+ return $choices->{$a}->[$section] cmp $choices->{$b}->[$section];
+ }
+ return $choices->{$a}->[$fullname] cmp $choices->{$b}->[$fullname];
+ } @keys;
+
+ my $type = 'radio';
+ if ($self->{'multichoice'}) { $type = 'checkbox'; }
+ $result .= "<table cellspacing='2' cellpadding='2' border='0'>\n";
+ $result .= "<tr><td></td><td align='center'><b>Student Name</b></td>".
+ "<td align='center'><b>Section</b></td></tr>";
+
+ my $checked = 0;
+ foreach (@keys) {
+ $result .= "<tr><td><input type='$type' name='" .
+ $self->{'variable'} . '.forminput' . "'";
+
+ if (!$self->{'multichoice'} && !$checked) {
+ $result .= " checked ";
+ $checked = 1;
+ }
+ $result .=
+ " value='" . HTML::Entities::encode($_)
+ . "' /></td><td>"
+ . HTML::Entities::encode($choices->{$_}->[$fullname])
+ . "</td><td align='center'>"
+ . HTML::Entities::encode($choices->{$_}->[$section])
+ . "</td></tr>\n";
+ }
+
+ $result .= "</table>\n\n";
+ $result .= $buttons;
+
+ return $result;
+}
+
+1;
+
+package Apache::lonhelper::files;
+
+=pod
+
+=head2 Element: files
+
+files allows the users to choose files from a given directory on the
+server. It is always multichoice and stores the result as a triple-pipe
+delimited entry in the helper variables.
+
+Since it is extremely unlikely that you can actually code a constant
+representing the directory you wish to allow the user to search, <files>
+takes a subroutine that returns the name of the directory you wish to
+have the user browse.
+
+files accepts the attribute "variable" to control where the files chosen
+are put. It accepts the attribute "multichoice" as the other attribute,
+defaulting to false, which if true will allow the user to select more
+then one choice.
+
+<files> accepts three subtags. One is the "nextstate" sub-tag that works
+as it does with the other tags. Another is a <filechoice> sub tag that
+is Perl code that, when surrounded by "sub {" and "}" will return a
+string representing what directory on the server to allow the user to
+choose files from. Finally, the <filefilter> subtag should contain Perl
+code that when surrounded by "sub { my $filename = shift; " and "}",
+returns a true value if the user can pick that file, or false otherwise.
+The filename passed to the function will be just the name of the file,
+with no path info.
+
+=cut
+
+no strict;
+@ISA = ("Apache::lonhelper::element");
+use strict;
+
+BEGIN {
+ &Apache::lonxml::register('Apache::lonhelper::files',
+ ('files', 'filechoice', 'filefilter'));
+}
+
+sub new {
+ my $ref = Apache::lonhelper::element->new();
+ bless($ref);
+}
+
+sub start_files {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+ $paramHash->{'variable'} = $token->[2]{'variable'};
+ $helper->declareVar($paramHash->{'variable'});
+ $paramHash->{'multichoice'} = $token->[2]{'multichoice'};
+}
+
+sub end_files {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+ if (!defined($paramHash->{FILTER_FUNC})) {
+ $paramHash->{FILTER_FUNC} = sub { return 1; };
+ }
+ Apache::lonhelper::files->new();
+}
+
+sub start_filechoice {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+ $paramHash->{'filechoice'} = Apache::lonxml::get_all_text('/filechoice',
+ $parser);
+}
+
+sub end_filechoice { return ''; }
+
+sub start_filefilter {
+ my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
+
+ if ($target ne 'helper') {
+ return '';
+ }
+
+ my $contents = Apache::lonxml::get_all_text('/filefilter',
+ $parser);
+ $contents = 'sub { my $filename = shift; ' . $contents . '}';
+ $paramHash->{FILTER_FUNC} = eval $contents;
+}
+
+sub end_filefilter { return ''; }
+
+sub render {
+ my $self = shift;
+ my $result = '';
+ my $var = $self->{'variable'};
+
+ my $subdirFunc = eval('sub {' . $self->{'filechoice'} . '}');
+ my $subdir = &$subdirFunc();
+
+ my $filterFunc = $self->{FILTER_FUNC};
+ my $buttons = '';
+
+ if ($self->{'multichoice'}) {
+ $result = <<SCRIPT;
+<script>
+ function checkall(value) {
+ for (i=0; i<document.forms.wizform.elements.length; i++) {
+ ele = document.forms.wizform.elements[i];
+ if (ele.type == "checkbox") {
+ document.forms.wizform.elements[i].checked=value;
+ }
+ }
+ }
+</script>
+SCRIPT
+ my $buttons = <<BUTTONS;
+<br />
+<input type="button" onclick="checkall(true)" value="Select All" />
+<input type="button" onclick="checkall(false)" value="Unselect All" />
+<br />
+BUTTONS
+ }
+
+ # Get the list of files in this directory.
+ my @fileList;
+
+ # If the subdirectory is in local CSTR space
+ if ($subdir =~ m|/home/([^/]+)/public_html|) {
+ my $user = $1;
+ my $domain = $Apache::lonnet::perlvar{'lonDefDomain'};
+ @fileList = &Apache::lonnet::dirlist($subdir, $domain, $user, '');
+ } else {
+ # local library server resource space
+ @fileList = &Apache::lonnet::dirlist($subdir, $ENV{'user.domain'}, $ENV{'user.name'}, '');
+ }
+
+ $result .= $buttons;
+
+ $result .= '<table border="0" cellpadding="1" cellspacing="1">';
+
+ # Keeps track if there are no choices, prints appropriate error
+ # if there are none.
+ my $choices = 0;
+ my $type = 'radio';
+ if ($self->{'multichoice'}) {
+ $type = 'checkbox';
+ }
+ # Print each legitimate file choice.
+ for my $file (@fileList) {
+ $file = (split(/&/, $file))[0];
+ if ($file eq '.' || $file eq '..') {
+ next;
+ }
+ my $fileName = $subdir .'/'. $file;
+ if (&$filterFunc($file)) {
+ $result .= '<tr><td align="right">' .
+ "<input type='$type' name='" . $var
+ . ".forminput' value='" . HTML::Entities::encode($fileName) .
+ "'";
+ if (!$self->{'multichoice'} && $choices == 0) {
+ $result .= ' checked';
+ }
+ $result .= "/></td><td>" . $file . "</td></tr>\n";
+ $choices++;
+ }
+ }
+
+ $result .= "</table>\n";
+
+ if (!$choices) {
+ $result .= '<font color="#FF0000">There are no files available to select in this directory. Please go back and select another option.</font><br /><br />';
+ }
+
+ $result .= $buttons;
+
+ return $result;
+}
+
+sub postprocess {
+ my $self = shift;
+ if ($self->{'multichoice'}) {
+ $self->process_multiple_choices($self->{'variable'}.'.forminput',
+ $self->{'variable'});
+ }
+ if (defined($self->{NEXTSTATE})) {
+ $helper->changeState($self->{NEXTSTATE});
+ }
+}
1;
__END__
+