sequencinglib.php

很棒的在线教学系统

	}
}

function scorm_seq_flow_activity_traversal ($activity, $userid, $direction, $childrenflag, $prevdirection, $seq,$userid){//returns the next activity on the tree, traversal direction, control returned to the LTS, (may) exception
    $activity = scorm_get_sco ($activity);
    $parent = scorm_get_parent ($activity);
   if (!isset($parent->flow) || ($parent->flow == false)) {
		$seq->deliverable = false;
	    $seq->exception = 'SB.2.2-1';
		$seq->nextactivity = $activity;
	    return $seq;
	}
     
    $rulch = scorm_seq_rules_check($sco, 'skipped');
	if ($rulch != null){
	    $seq = scorm_seq_flow_tree_traversal ($activity, $direction, false, $prevdirection, $seq,$userid);//endsession and exception
		if ($seq->identifiedactivity == null){
			$seq->deliverable = false;
			$seq->nextactivity = $activity;
			return $seq;
		}
		else{
			
			if ($prevdirection = 'backward' && $seq->traversaldir == 'backward'){
				$seq = scorm_seq_flow_tree_traversal ($activity,$direction,false,null,$seq,$userid);
				$seq = scorm_seq_flow_activity($seq->identifiedactivity, $userid, $direction, $childrenflag, $prevdirection, $seq,$userid);
			}
			else{
				$seq = scorm_seq_flow_tree_traversal ($activity,$direction,false,null,$seq,$userid);
				$seq = scorm_seq_flow_activity($seq->identifiedactivity, $userid, $direction, $childrenflag, $prevdirection, $seq,$userid);
			}
			return $seq;
		}
	}

	$ch=scorm_check_activity ($activity,$userid);

	if ($ch){

		$seq->deliverable = false;
	    $seq->exception = 'SB.2.2-2';
		$seq->nextactivity = $activity;
	    return $seq;

	}

	if (!scorm_is_leaf($activity)){

		$seq = scorm_seq_flow_tree_traversal ($activity,$direction,true,null,$seq,$userid);

		if ($seq->identifiedactivity == null){
			$seq->deliverable = false;
			$seq->nextactivity = $activity;
			return $seq;
		}

		else{
		    if($direction == 'backward' && $seq->traversaldir == 'forward'){
				$seq = scorm_seq_flow_activity($seq->identifiedactivity, $userid, 'forward', $childrenflag, 'backward', $seq,$userid);
			}
			else{
				scorm_seq_flow_activity($seq->identifiedactivity, $userid, $direction, $childrenflag, null, $seq,$userid);
			}
			return $seq;
		}

	}

    $seq->deliverable = true;
	$seq->nextactivity = $activity;
    return $seq;

}
function scorm_seq_flow_tree_traversal ($activity,$direction,$childrenflag,$prevdirection,$seq,$userid){

	$revdirection = false;
	$parent = scorm_get_parent ($activity);
	$children = scorm_get_available_children ($parent);
	$siz = sizeof ($children);

    if (($prevdirection != null && $prevdirection == 'backward') && ($children[$siz-1]->id == $activity->id)){
		$direction = 'backward';
		$children[0] = $activity;
		$revdirection = true;
	}

	if($direction = 'forward'){
		$ancestors = scorm_get_ancestors($activity);
		$ancestorsroot = array_reverse($ancestors);
		$preorder = scorm_get_preorder ($ancestorsroot);
		$siz= sizeof ($preorder);
		if (($activity->id == $preorder[$siz-1]->id) || (($activity->parent == '/') && !($childrenflag))){
			scorm_seq_terminate_descent($ancestorsroot,$userid);
			$seq->endsession = true;
			$seq->nextactivity = null;
			return $seq;
		}
		if (scorm_is_leaf ($activity) || !$childrenflag){
			if ($children[$siz-1]->id == $activity->id){
	
				$seq = scorm_seq_flow_tree_traversal ($parent, $direction, false, null, $seq,$userid);
				// I think it's not necessary to do a return in here
			}
			else{
				$parent = scorm_get_parent($activity);
				$children = scorm_get_available_children($parent);
				$seq->traversaldir = $direction;
				$sib = scorm_get_siblings($activity);
				$pos = array_search($sib, $activity);
				if ($pos !== false) {
				    if ($pos != sizeof ($sib)){
				        $seq->nextactivity = $sib [$pos+1];
						return $seq;
				    }
				    else{
					    $ch = scorm_get_children($sib[0]);
					    $seq->nextactivity = $ch[0];
						return $seq;
				    }
				}
		    }
		}
		else{
			if (!empty ($children)){
				$seq->traversaldir = $direction;
                $seq->nextactivity = $children[0];
				return $seq;
			}
			else{
				$seq->traversaldir = null;
                $seq->nextactivity = $children[0];
				$seq->exception = 'SB.2.1-2';
				return $seq;
			}
		}
		
	}
	if($direction = 'backward'){
		
		 if ($activity->parent == '/'){
			$seq->traversaldir = null;
            $seq->nextactivity = null;
			$seq->exception = 'SB.2.1-3';
			return $seq;
		 }
		 if (scorm_is_leaf ($activity) || !$childrenflag){
			 if (!$revdirection){
				 if (isset($parent->forwardonly) && ($parent->forwardonly == true)) {
					 $seq->traversaldir = null;
                     $seq->nextactivity = null;
			         $seq->exception = 'SB.2.1-4';
					 return $seq;
				 }
			 }
			 if ($children[0]->id == $activity->id){
				$seq = scorm_seq_flow_tree_traversal ($parent, 'backward', false, null, $seq);
				return $seq;
			 }
			 else{
				$ancestors = scorm_get_ancestors($activity);
		        $ancestorsroot = array_reverse ($ancestors);
				$preorder = scorm_get_preorder ($ancestorsroot);
				$pos = array_search($preorder, $children[$siz]);
				$preord = array_slice($preorder, 0, $pos-1);
				$revpreorder = array_reverse($preord);
				$position = array_search($revpreorder, $activity);
				$seq->nextactivity = $revpreorder[$pos+1];
				$seq->traversaldir = $direction;
				return $seq;
			 }
		 }
		 else{
			 if (!empty($children)){
				 $activity = scorm_get_sco($activity->id);
				 if (isset($parent->flow) && ($parent->flow == true)) {
					 $children = scorm_get_children ($activity);
					 $seq->traversaldir = 'forward';
                     $seq->nextactivity = $children[0];
					 return $seq;
			         
				 }
				 else{
					 $children = scorm_get_children ($activity);
					 $seq->traversaldir = 'backward';
                     $seq->nextactivity = $children[sizeof($children)-1];
					 return $seq;
				 }

			 }
			 else{
				 
					 $seq->traversaldir = null;
                     $seq->nextactivity = null;
					 $seq->exception = 'SB.2.1-2';
					 return $seq;
			 }
		 }

	}


}
function scorm_check_activity ($activity,$userid){
	$act = scorm_seq_rules_check($activity,'disabled');
	if ($act != null){
		return true;
	}
    if(scorm_limit_cond_check ($activity,$userid)){
		return true;
	}
	return false;


}

function scorm_limit_cond_check ($activity,$userid){

    if (isset($activity->tracked) && ($activity->tracked == 0)){
		
		return false;
	}

	if (scorm_seq_is('active',$activity->id,$userid) || scorm_seq_is('suspended',$activity->id,$userid)){
		return false;
	}

    if (!isset($activity->limitcontrol) || ($activity->limitcontrol == 1)){	
		$r = get_record('scorm_scoes_track','scoid',$activity->id,'userid',$userid,'element','activityattemptcount');
		if (scorm_seq_is('activityprogressstatus',$activity->id,$userid) && ($r->value >=$activity->limitattempt)){
			return true;
		}
	}

	 if (!isset($activity->limitabsdurcontrol) || ($activity->limitabsdurcontrol == 1)){	
		$r = get_record('scorm_scoes_track','scoid',$activity->id,'userid',$userid,'element','activityabsoluteduration');
		if (scorm_seq_is('activityprogressstatus',$activity->id,$userid) && ($r->value >=$activity->limitabsduration)){
			return true;
		}
	}

	if (!isset($activity->limitexpdurcontrol) || ($activity->limitexpdurcontrol == 1)){	
		$r = get_record('scorm_scoes_track','scoid',$activity->id,'userid',$userid,'element','activityexperiencedduration');
		if (scorm_seq_is('activityprogressstatus',$activity->id,$userid) && ($r->value >=$activity->limitexpduration)){
			return true;
		}
	}
    
	 if (!isset($activity->limitattabsdurcontrol) || ($activity->limitattabsdurcontrol == 1)){	
		$r = get_record('scorm_scoes_track','scoid',$activity->id,'userid',$userid,'element','attemptabsoluteduration');
		if (scorm_seq_is('activityprogressstatus',$activity->id,$userid) && ($r->value >=$activity->limitattabsduration)){
			return true;
		}
	}

	if (!isset($activity->limitattexpdurcontrol) || ($activity->limitattexpdurcontrol == 1)){	
		$r = get_record('scorm_scoes_track','scoid',$activity->id,'userid',$userid,'element','attemptexperiencedduration');
		if (scorm_seq_is('activityprogressstatus',$activity->id,$userid) && ($r->value >=$activity->limitattexpduration)){
			return true;
		}
	}

	if (!isset($activity->limitbegincontrol) || ($activity->limitbegincontrol == 1)){	
		$r = get_record('scorm_scoes_track','scoid',$activity->id,'userid',$userid,'element','begintime');
		if (time()>=$activity->limitbegintime){
			return true;
		}
	}

	if (!isset($activity->limitbegincontrol) || ($activity->limitbegincontrol == 1)){	
		if (time()<$activity->limitbegintime){
			return true;
		}
	}

	if (!isset($activity->limitendcontrol) || ($activity->limitendcontrol == 1)){	

		if (time()>$activity->limitendtime){
			return true;
		}
	}
	return false;


}


function scorm_seq_choice_sequencing($sco,$userid,$seq){

	$avchildren = Array ();
	$comancestor = null;
	$traverse = null;

	if ($sco == null){
		$seq->delivery = null;
		$seq->exception = 'SB.2.9-1';
		return $seq;
	}

    $ancestors = scorm_get_ancestors($sco);
    $arrpath = array_reverse($ancestors);
	array_push ($arrpath,$sco);//path from the root to the target

	foreach ($arrpath as $activity){

        if ($activity->parent != '/') {
			$avchildren = scorm_get_available_children (scorm_get_parent($activity));
			$position = array_search($avchildren, $activity);
            if ($position !== false){
				$seq->delivery = null;
		        $seq->exception = 'SB.2.9-2';
		        return $seq;
			}
		}

		if (scorm_seq_rules_check($activity,'hidefromchoice' != null)){

			$seq->delivery = null;
		    $seq->exception = 'SB.2.9-3';
		    return $seq;

		}

	}

	if ($sco->parent != '/') {
		$parent = scorm_sco_get_parent ($sco);
		if ( isset($parent->choice) && ($parent->choice == false)){
			$seq->delivery = null;
		    $seq->exception = 'SB.2.9-4';
		    return $seq;
		}
	}

	if ($seq->currentactivity != null){
        $commonpos = scorm_find_common_ancestor($ancestors,$seq->currentactivity);
		$comancestor = $arrpath [$commonpos];
	}
	else{
		$comancestor = $arrpath [0];
	}

	if($seq->currentactivity === $sco) {
        break;
	}

	$sib = scorm_get_siblings($seq->currentactivity);
	$pos = array_search($sib, $sco);

	if ($pos !== false){

		$siblings = array_slice($sib, 0, $pos-1);

		if (empty($siblings)){

			$seq->delivery = null;
		    $seq->exception = 'SB.2.9-5';
		    return $seq;

		}
        
		$children = scorm_get_children (scorm_get_parent ($sco));
		$pos1 = array_search($children, $sco);
		$pos2 = array_search($seq->currentactivity, $sco);
		if ($pos1>$pos2){
			$traverse = 'forward';
		}
		else{
			$traverse = 'backward';
		}

		foreach ($siblings as $sibling){
			$seq = scorm_seq_choice_activity_traversal($sibling,$userid,$seq,$traverse);
		    if(!$seq->reachable){
			    $seq->delivery = null;
			    return $seq;
		    }
		}
		break;

	}

    if($seq->currentactivity == null || $seq->currentactivity == $comancestor){
		$commonpos = scorm_find_common_ancestor($ancestors,$seq->currentactivity);
		$comtarget = array_slice($ancestors, 1,$commonpos-1);//path from the common ancestor to the target activity
		$comtarget = array_reverse($comtarget);

		if (empty($comtarget)){
			$seq->delivery = null;
		    $seq->exception = 'SB.2.9-5';
		    return $seq;
		}
		foreach ($comtarget as $act){
			$seq = scorm_seq_choice_activity_traversal($act,$userid,$seq,'forward');
		    if(!$seq->reachable){
			    $seq->delivery = null;
			    return $seq;
		    }
            $act = scorm_get_sco ($acti->id);
			if(scorm_seq_is('active',$act->id,$userid) && ($act->id != $comancestor->id && $act->preventactivation)){//adlseq:can i write it like another property for the $seq object?
				$seq->delivery = null;
		        $seq->exception = 'SB.2.9-6';
		        return $seq;
			}
		}
		break;

	}

	if ($comancestor->id == $sco->id){

        $ancestorscurrent = scorm_get_ancestors($seq->currentactivity);
		$possco = array_search ($ancestorscurrent, $sco);
		$curtarget = array_slice($ancestorscurrent,0,$possco);//path from the current activity to the target

		if (empty($curtarget)){
			$seq->delivery = null;
		    $seq->exception = 'SB.2.9-5';
		    return $seq;
		}
        $i=0;
		foreach ($curtarget as $activ){
			$i++;
			if ($i != sizeof($curtarget)){
				if ( isset($activ->choiceexit) && ($activ->choiceexit == false)){
					$seq->delivery = null;
		            $seq->exception = 'SB.2.9-7';