--- rat/lonuserstate.pm 2011/07/26 10:40:23 1.138
+++ rat/lonuserstate.pm 2011/08/04 10:57:26 1.139
@@ -1,7 +1,7 @@
# The LearningOnline Network with CAPA
# Construct and maintain state and binary representation of course for user
#
-# $Id: lonuserstate.pm,v 1.138 2011/07/26 10:40:23 foxr Exp $
+# $Id: lonuserstate.pm,v 1.139 2011/08/04 10:57:26 foxr Exp $
#
# Copyright Michigan State University Board of Trustees
#
@@ -70,6 +70,21 @@ sub versionerror {
$uri,$usedversion,$unusedversion).' ';
}
+# Removes the version number from a URI and returns the resulting
+# URI (e.g. mumbly.version.stuff => mumbly.stuff).
+#
+# If the URI has not been seen with a versio before the
+# hash{'version_'.resultingURI} is set to the version number.
+# If the URI has been seen and the version does not match and error
+# is added to the error string.
+#
+# Parameters:
+# URI potentially with a version.
+# Returns:
+# URI with the version cut out.
+# See above for side effects.
+#
+
sub versiontrack {
my $uri=shift;
if ($uri=~/\.(\d+)\.\w+$/) {
@@ -218,7 +233,7 @@ sub loadmap {
if ($token->[1] eq 'resource') {
my $resource_id = &parse_resource($token,$lpc,$ispage,$uri);
if (defined $resource_id) {
- push(@map_ids, $resource_id);
+ push(@map_ids, $resource_id);
}
# Link
@@ -226,7 +241,7 @@ sub loadmap {
} elsif ($token->[1] eq 'link' && !$randomize) {
&make_link(++$linkpc,$lpc,$token->[2]->{'to'},
$token->[2]->{'from'},
- $token->[2]->{'condition'});
+ $token->[2]->{'condition'}); # note ..condition may be undefined.
# condition
@@ -241,9 +256,17 @@ sub loadmap {
if ($randomize) {
if (!$env{'request.role.adv'}) {
my $seed;
+
+ # In the advanced role, the map's random seed
+ # parameter is used as the basis for computing the
+ # seed ... if it has been specified:
+
if (defined($randompickseed{$parent_rid})) {
$seed = $randompickseed{$parent_rid};
} else {
+
+ # Otherwise the parent's fully encoded symb is used.
+
my ($mapid,$resid)=split(/\./,$parent_rid);
my $symb=
&Apache::lonnet::encode_symb($hash{'map_id_'.$mapid},
@@ -252,18 +275,26 @@ sub loadmap {
$seed = $symb;
}
- # Here for sure we need to pass along the username/domain
+ # TODO: Here for sure we need to pass along the username/domain
# so that we can impersonate users in lonprintout e.g.
my $rndseed=&Apache::lonnet::rndseed($seed);
&Apache::lonnet::setup_random_from_rndseed($rndseed);
- @map_ids=&Math::Random::random_permutation(@map_ids);
+ @map_ids=&math::Random::random_permutation(@map_ids); # randomorder.
}
+
+
my $from = shift(@map_ids);
my $from_rid = $lpc.'.'.$from;
$hash{'map_start_'.$uri} = $from_rid;
$hash{'type_'.$from_rid}='start';
+ # Create links to reflect this random ordering.
+ # BUG? If there are conditions, this invalidates them? Then again
+ # with randompick there's no gaurentee the resources required for the
+ # conditinos to work will be selected into the map.
+ # so randompick is inconsistent with a map that has conditions?
+
while (my $to = shift(@map_ids)) {
&make_link(++$linkpc,$lpc,$to,$from);
my $to_rid = $lpc.'.'.$to;
@@ -278,8 +309,10 @@ sub loadmap {
$parser = HTML::TokeParser->new(\$instr);
$parser->attr_encoded(1);
+
# last parse out the mapalias params so as to ignore anything
# refering to non-existant resources
+
while (my $token = $parser->get_token) {
next if ($token->[0] ne 'S');
if ($token->[1] eq 'param') {
@@ -305,6 +338,7 @@ sub loadmap {
# $ispage - True if this resource is encapsulated in a .page (assembled resourcde).
# $uri - URI of the enclosing resource.
# Returns:
+# Value of the id attribute of the tag.
#
# Note:
# The token is an array that contains the following elements:
@@ -325,10 +359,14 @@ sub loadmap {
sub parse_resource {
my ($token,$lpc,$ispage,$uri) = @_;
- # I refuse to coutenance code like this that has
+ # I refuse to countenance code like this that has
# such a dirty side effect (and forcing this sub to be called within a loop).
#
# if ($token->[2]->{'type'} eq 'zombie') { next; }
+ #
+ # The original code both returns _and_ skips to the next pass of the >caller's<
+ # loop, that's just dirty.
+ #
# Zombie resources don't produce anything useful.
@@ -336,22 +374,38 @@ sub parse_resource {
return undef;
}
- my $rid=$lpc.'.'.$token->[2]->{'id'};
+ my $rid=$lpc.'.'.$token->[2]->{'id'}; # Resource id in hash is levelcounter.id-in-xml.
+
+ # Save the hash element type and title:
$hash{'kind_'.$rid}='res';
$hash{'title_'.$rid}=$token->[2]->{'title'};
+
+ # Get the version free URI for the resource.
+ # If a 'version' attribute was supplied, and this resource's version
+ # information has not yet been stored, store it.
+ #
+
my $turi=&versiontrack($token->[2]->{'src'});
if ($token->[2]->{'version'}) {
unless ($hash{'version_'.$turi}) {
$hash{'version_'.$turi}=$1;
}
}
+ # Pull out the title and do entity substitution on &colon
+ # Q: Why no other entity substitutions?
+
my $title=$token->[2]->{'title'};
$title=~s/\&colon\;/\:/gs;
-# my $symb=&Apache::lonnet::encode_symb($uri,
-# $token->[2]->{'id'},
-# $turi);
-# &Apache::lonnet::do_cache_new('title',$symb,$title);
+
+
+
+ # I think the point of all this code is to construct a final
+ # URI that apache and its rewrite rules can use to
+ # fetch the resource. Thi s sonly necessary if the resource
+ # is not a page. If the resource is a page then it must be
+ # assembled (at fetch time?).
+
unless ($ispage) {
$turi=~/\.(\w+)$/;
my $embstyle=&Apache::loncommon::fileembstyle($1);
@@ -378,7 +432,10 @@ sub parse_resource {
}
}
}
-# Store reverse lookup, remove query string
+ # Store reverse lookup, remove query string resource 'ids'_uri => resource id.
+ # If the URI appears more than one time in the sequence, it's resourcde
+ # id's are constructed as a comma spearated list.
+
my $idsuri=$turi;
$idsuri=~s/\?.+$//;
if (defined($hash{'ids_'.$idsuri})) {
@@ -387,17 +444,37 @@ sub parse_resource {
$hash{'ids_'.$idsuri}=''.$rid;
}
+
+
if ($turi=~/\/(syllabus|aboutme|navmaps|smppg|bulletinboard|viewclasslist)$/) {
$turi.='?register=1';
}
+
+ # resource id lookup: 'src'_resourc-di => URI decorated with a query
+ # parameter as above if necessary due to the resource type.
+
$hash{'src_'.$rid}=$turi;
+
+ # Mark the external-ness of the resource:
if ($token->[2]->{'external'} eq 'true') {
$hash{'ext_'.$rid}='true:';
} else {
$hash{'ext_'.$rid}='false:';
}
+
+ # If the resource is a start/finish resource set those
+ # entries in the has so that navigation knows where everything starts.
+ # TODO? If there is a malformed sequence that has no start or no finish
+ # resource, should this be detected and errors thrown? How would such a
+ # resource come into being other than being manually constructed by a person
+ # and then uploaded? Could that happen if an author decided a sequence was almost
+ # right edited it by hand and then reuploaded it to 'fix it' but accidently cut the
+ # start or finish resources?
+ #
+ # All resourcess also get a type_id => (start | finish | normal) hash entr.
+ #
if ($token->[2]->{'type'}) {
$hash{'type_'.$rid}=$token->[2]->{'type'};
if ($token->[2]->{'type'} eq 'start') {
@@ -409,6 +486,12 @@ sub parse_resource {
} else {
$hash{'type_'.$rid}='normal';
}
+
+ # Sequences end pages are constructed entities. They require that the
+ # map that defines _them_ be loaded as well into the hash...with this resourcde
+ # as the base of the nesting.
+ # Resources like that are also marked with is_map_id => 1 entries.
+ #
if (($turi=~/\.sequence$/) ||
($turi=~/\.page$/)) {
@@ -418,22 +501,65 @@ sub parse_resource {
return $token->[2]->{'id'};
}
+#-------------------------------------------------------------------- link
+# Links define how you are allowed to move from one resource to another.
+# They are the transition edges in the directed graph that a map is.
+# This sub takes informatino from a tag and constructs the
+# navigation bits and pieces of a map. There is no requirement that the
+# resources that are linke are already defined, however clearly the map is
+# badly broken if they are not _eventually_ defined.
+#
+# Note that links can be unconditional or conditional.
+#
+# Parameters:
+# linkpc - The link counter for this level of map nesting (this is
+# reset to zero by loadmap prior to starting to process
+# links for map).
+# lpc - The map level ocounter (how deeply nested this map is in
+# the hierarchy of maps that are recursively read in.
+# to - resource id (within the XML) of the target of the edge.
+# from - resource id (within the XML) of the source of the edge.
+# condition- id of condition associated with the edge (also within the XML).
+#
+
sub make_link {
my ($linkpc,$lpc,$to,$from,$condition) = @_;
+ # Compute fully qualified ids for the link, the
+ # and from/to by prepending lpc.
+ #
+
my $linkid=$lpc.'.'.$linkpc;
my $goesto=$lpc.'.'.$to;
my $comesfrom=$lpc.'.'.$from;
my $undercond=0;
+
+ # If there is a condition, qualify it with the level counter.
+
if ($condition) {
$undercond=$lpc.'.'.$condition;
}
+ # Links are represnted by:
+ # goesto_.fuullyqualifedlinkid => fully qualified to
+ # comesfrom.fullyqualifiedlinkid => fully qualified from
+ # undercond_.fullyqualifiedlinkid => fully qualified condition id.
+
$hash{'goesto_'.$linkid}=$goesto;
$hash{'comesfrom_'.$linkid}=$comesfrom;
$hash{'undercond_'.$linkid}=$undercond;
+ # In addition:
+ # to_.fully qualified from => comma separated list of
+ # link ids with that from.
+ # Similarly:
+ # from_.fully qualified to => comma separated list of link ids`
+ # with that to.
+ # That allows us given a resource id to know all edges that go to it
+ # and leave from it.
+ #
+
if (defined($hash{'to_'.$comesfrom})) {
$hash{'to_'.$comesfrom}.=','.$linkid;
} else {
@@ -447,6 +573,54 @@ sub make_link {
}
# ------------------------------------------------------------------- Condition
+#
+# Processes tags, storing sufficient information about them
+# in the hash so that they can be evaluated and used to conditionalize
+# what is presented to the student.
+#
+# these can have the following attributes
+#
+# id = A unique identifier of the condition within the map.
+#
+# value = Is a perl script-let that, when evaluated in safe space
+# determines whether or not the condition is true.
+# Normally this takes the form of a test on an Apache::lonnet::EXT call
+# to find the value of variable associated with a resource in the
+# map identified by a mapalias.
+# Here's a fragment of XML code that illustrates this:
+#
+#
+#
+#
+#
+#
+#
+# In this fragment:
+# - The param tag establishes an alias to resource id 5 of 'mainproblem'.
+# - The resource that is the start of the map is identified.
+# - The resource tag identifies the resource associated with this tag
+# and gives it the id 5.
+# - The condition is true if the tries variable associated with mainproblem
+# is less than 2 (that is the user has had more than 2 tries).
+# The condition type is a stop condition which inhibits(?) the associated
+# link if the condition is false.
+# - The link to resource 5 from resource 1 is affected by this condition.
+#
+# type = Type of the condition. The type determines how the condition affects the
+# link associated with it and is one of
+# - 'force'
+# - 'stop'
+# anything else including not supplied..which treated as:
+# - 'normal'.
+# Presumably maps get created by the resource assembly tool and therefore
+# illegal type values won't squirm their way into the XML.
+#
+# Side effects:
+# - The kind_level-qualified-condition-id hash element is set to 'cond'.
+# - The condition text is pushed into the cond array and its element number is
+# set in the condid_level-qualified-condition-id element of the hash.
+# - The condition type is colon appneded to the cond array element for this condition.
sub parse_condition {
my ($token,$lpc) = @_;
my $rid=$lpc.'.'.$token->[2]->{'id'};
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