referenceHasMetaData (metaDataKey, metadataValue)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

..	list-table:: 
	:widths: 20 80
	:header-rows: 0
	:class: tight-table

	*	-	Category
		-	metadata functions
	*	-	Signature
		-	referenceHasMetaData(String metadataKey, String metadataValue) : boolean
	*	-	Description
		-	Checks if the model reference in the context has a certain metadata key with a certain metadata value.
	*	-	Arguments
		-	- metadataKey: key of metadata to check for existence
			- metadataValue: value of metadata to check for existence
	*	-	Returns
		-	- true if the model reference in the context has the metadata key with the given metadata value
			- false if the model reference in the context does not have the metadata key or has the metadata
				key with a metadata value different from the given metadata value.
	*	-	Exceptions
		- .. error::
			This function raises a *No model reference in context* exception when the context does not contain a model reference.
	*	-	Example
		-	The following example shows a code instruction that generates a Java class for each object,
			and conditionally generates a comment for a Java field for each reference that has metadata *bar* with value *baz*.

			Given the input in the input section below CodeComposer will generate the file(s) as shown in the output section below.
			
			**Input**

			.. code-block:: xml
				:caption: src/codeinstruction/examples/example-code-instruction-simple-entity-foreach-reference-and-reference-has-meta-data-with-value.xml
				:name: ReferenceHasMetaDataWithValue_CodeInstruction
				:linenos:
				:emphasize-lines: 13, 15
				
				<?xml version="1.0" encoding="UTF-8"?>
				<java_package xmlns="https://metafactory.io/xsd/v1/java-codeinstruction"
				              xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
				              xsi:schemaLocation="https://metafactory.io/xsd/v1/java-codeinstruction https://metafactory.io/xsd/v1/java-codeinstruction.xsd"
				              name="${pattern.property.java.package.base}.entities.simple"
				              path="${pattern.property.java.main.directory}"
				              package="domain_model">
				  <class  name="${createSimpleEntityClassName(${object.name})}"
				          foreach="object">
				    <field	name="${reference.name}"
				            access="rw"
				            foreach="reference"
				            condition="${referenceHasMetaData(bar,baz)}"
				    >
				      <apicommentline>${fmsnippet.examples.exampleCommentForReferenceThatHasMetaDataBarWithValueBaz}</apicommentline>
				    </field>
				  </class>
				</java_package>

			.. code-block::
				:caption: src/snippet/examples/exampleCommentForReferenceThatHasMetaDataBarWithValueBaz.ftl
				:name: ReferenceHasMetaDataWithValue_Snippet1
				:linenos:
				:emphasize-lines: 3

				<#if !(modelReference)??>  <#stop "modelReference not found in context" ></#if>

				This is an example comment for a reference with meta data bar with value baz: ${modelReference.type} ${modelReference.name}. 
							
			.. code-block:: xml
				:caption: src/model/model.xml
				:name: ReferenceHasMetaDataWithValue_Model
				:linenos:
				:emphasize-lines: 20
				
				<?xml version="1.0" encoding="UTF-8"?>
				<model xmlns="https://metafactory.io/xsd/v1/model" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="https://metafactory.io/xsd/v1/model https://metafactory.io/xsd/v1/model.xsd">
					<package name="domain_model">
						<object name="ExampleObject4">
							<metadata>
								<name.plural>ExampleObjects4</name.plural>
								<serialVersionUID>0</serialVersionUID>
							</metadata>
							<reference name="exampleObject1" type="ExampleObject1" multiplicity="1..1" notnull="true">
								<metadata>
								</metadata>
							</reference>
							<reference name="exampleObject2" type="ExampleObject2" multiplicity="1..1" notnull="true">
								<metadata>
									<bar></bar>
								</metadata>
							</reference>
							<reference name="exampleObject3" type="ExampleObject3" multiplicity="1..1" notnull="true">
								<metadata>
									<bar>baz</bar>
								</metadata>
							</reference>
						</object>
					</package>
				</model>

			**Output**

			.. code-block:: java
				:caption: src/main/java/io/metafactory/codecomposer_reference/entities/simple/ExampleObject4SimpleEntity.java
				:name: ReferenceHasMetaDataWithValue_Output1
				:linenos:
				:emphasize-lines: 22
	
				package io.metafactory.codecomposer_reference.entities.simple;

				/**
				 * This is an example comment for a reference with any multiplicity: ExampleObject1 exampleObject1.
				 * This is an example comment for a reference with multiplicity 0..1 or 1..1: ExampleObject1 exampleObject1.
				 */
				private ExampleObject1SimpleEntity exampleObject1;
		
		
				/**
				 * This is an example comment for a reference with any multiplicity: ExampleObject2 exampleObject2.
				 * This is an example comment for a reference with multiplicity 0..1 or 1..1: ExampleObject2 exampleObject2.
				 * This is an example comment for a reference with meta data bar: ExampleObject2 exampleObject2.
				 */
				private ExampleObject2SimpleEntity exampleObject2;
		
		
				/**
				 * This is an example comment for a reference with any multiplicity: ExampleObject3 exampleObject3.
				 * This is an example comment for a reference with multiplicity 0..1 or 1..1: ExampleObject3 exampleObject3.
				 * This is an example comment for a reference with meta data bar: ExampleObject3 exampleObject3.
				 * This is an example comment for a reference with meta data bar with value baz: ExampleObject3 exampleObject3.
				 */
				private ExampleObject3SimpleEntity exampleObject3;