<instructional-design level="Web_Programiranje">	
	<uol-structure>
		<learning-object element-id="INTRODUCTION"><!-- introduction first -->
			<selection-rule>
				<include att-name="type" att-value="explanation-content"/>
				<include att-name="label" att-value="introduction"/>
			</selection-rule>
		</learning-object>		
		
		<sequence level = "lesson" element-id="LESSON_SEQUENCE" sequence-element-id="LESSON">		
			<sequence level = "topic" element-id="TOPIC_SEQUENCE"> 
				<learning-object>
					<selection-rule>
						<include att-name="type" att-value="explanation-content" priority="1"/>  
						<include att-name="type" att-value="examples" priority="2"/>  
						<include att-name="type" att-value="*" priority="3"/>  
						<exclude att-name="type" att-value="exercise"/>
					</selection-rule>					
				</learning-object>
			</sequence>
		</sequence>
		
		<sequence element = "lesson" element-id="TEST_LESSON_SEQUENCE">
			<learning-object element-id="TEST">
				<selection-rule>
					<include att-name="label" att-value="test"/>
				</selection-rule>
				<grading>
					<type>boolean</type>
				</grading>
			</learning-object>
		</sequence>				
	</uol-structure>
	
	<element-relationships>	
		<element-relationship>
			<element element-ref="INTRODUCTION" alias="i"/><!-- before lesson_sequence, we have to finish introduction -->
			<element element-ref="LESSON_SEQUENCE" alias="ls"/>	
			<conditions>
				<if> 
					<completed element="i"/>
				</if>
				<then>
					<show element="ls"/>
				</then>
				<else>
					<hide element="ls"/>
				</else>
			</conditions>
		</element-relationship>
		
		<element-relationship><!-- we create a relationship between 2 lessons -->
			<element element-ref="LESSON" alias="l1"/>
			<element element-ref="LESSON" alias="l2"/>
			<join> 
				<less-than><!-- we create a join between lesson and its following lesson  -->
					<index element="l1"/>
					<index element="l2"/>
				</less-than>						
			</join>
			<conditions>
				<if> 
					<not>
						<completed element="l1"/><!-- lesson is not available until we complete the previous one -->
					</not>
				</if>
				<then>
					<hide element="l2"/>
				</then>
				<else>
					<show element="l2"/>
				</else>
			</conditions>
		</element-relationship>		

		<element-relationship>
			<element element-ref="LESSON_SEQUENCE" alias="ls"/> <!-- before test_lesson_sequence, we have to finish lesson_sequence -->
			<element element-ref="TEST_LESSON_SEQUENCE" alias="ts"/>			
			<conditions>
				<if> 
					<completed element="ls"/>
				</if>
				<then>
					<show element="ts"/>
				</then>
				<else>
					<hide element="ts"/>
				</else>
			</conditions>
		</element-relationship>		

		<element-relationship>
			<element element-ref="LESSON" alias="lesson"/>
			<element element-ref="TEST" alias="test"/>			
			<join> 
				<equals> <!-- relation between test and its lesson -->
					<name element="lesson"/> 
					<parent-name element="test"/>
				</equals>						
			</join>				
			<conditions>			
				<if> 
					<completed element="test"/><!-- if student pass lesson test, we shouldn't show that lesson -->
				</if>
				<then>
					<hide element="lesson"/>
				</then>
				<else>
					<show element="lesson"/>
				</else>
			</conditions>
		</element-relationship>				
		
	</element-relationships>	
</instructional-design>

