objectHasMetaData (metaDataKey)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

..	list-table:: objectHasMetaData (metaDataKey)
	:widths: 20 80
	:header-rows: 0
	:class: tight-table

	*	-	Category
		-	metadata functions
	*	-	Signature
		-	objectHasMetaData(String metadataKey) : boolean
	*	-	Description
		-	check if an object has a certain metadata key
	*	-	Arguments
		-	metaDataKey: key of metadata to check for existence
	*	-	Returns
		-	- true if the model object in the context has the metadata key
			- false if the model object in the context does not have the metadata key
	*	-	Exceptions
		- .. error::
			This function raises a *No model object in context* exception when the context does not contain a model object
	*	-	Example
		-	The following example shows parts of a code instruction that generates a Java class for each object
			that has metadata *createSimpleService*.
			
			Given the input shown in the input section below CodeComposer will generate this class for object *ExampleObject1*, *ExampleObject2* and *ExampleObject3* as shown in the output section below.

			.. note::
				CodeComposer will generate the class for ExampleObject2 even though the createSimpleService metadata value is false in the model. 
			
			
			**Input**
			
			.. code-block:: xml
				:caption: src/codeinstruction/examples/example-code-instruction-simple-service-object-has-meta-data.xml
				:name: ObjectHasMetaData_CodeInstruction
				:linenos:
				:emphasize-lines: 10
				
				<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="${pattern.property.java.package.base}.services.simple"
				              path="${pattern.property.java.main.directory}"
				              package="domain_model"
				>
				  <class  name="${createSimpleServiceClassName(${object.name})}" 
				          foreach="object"
				          condition="${objectHasMetaData(createSimpleService)}">
				  </class>
				</java_package>
			
			.. code-block:: xml
				:caption: src/model/model.xml
				:name: ObjectHasMetaData_Model
				:linenos:
				:emphasize-lines: 6, 11, 16
				
				<?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="ExampleObject1">
					  <metadata>
							<createSimpleService></createSimpleService>
					  </metadata>
					</object>
					<object name="ExampleObject2">
					  <metadata>
							<createSimpleService>false</createSimpleService>
					  </metadata>
					</object>
					<object name="ExampleObject3">
					  <metadata>
							<createSimpleService>true</createSimpleService>
					  </metadata>
					</object>
				</model>
			
			**Output**

			.. code-block:: java
				:caption: src/main/java/io/metafactory/codecomposer_reference/services/simple/ExampleObject1SimpleService.java
				:name: ObjectHasMetaData_Output1
				:linenos:
				:emphasize-lines: 3
				
				package io.metafactory.codecomposer_reference.services.simple;

				public class ExampleObject1SimpleService {
				
				}
				
			.. code-block:: java
				:caption: src/main/java/io/metafactory/codecomposer_reference/services/simple/ExampleObject2SimpleService.java
				:name: ObjectHasMetaData_Output2
				:linenos:
				:emphasize-lines: 3

				package io.metafactory.codecomposer_reference.services.simple;
				
				public class ExampleObject2SimpleService {
				
				}
				
			.. code-block:: java
				:caption: src/main/java/io/metafactory/codecomposer_reference/services/simple/ExampleObject3SimpleService.java
				:name: ObjectHasMetaData_Output3
				:linenos:
				:emphasize-lines: 3

				package io.metafactory.codecomposer_reference.services.simple;
				
				public class ExampleObject3SimpleService {
				
				}