Value Mapping Functoid

The Value Mapping functoid returns the value of its second parameter if its first parameter is true. A common use of the functoid is to change the attributes of a field into the attributes of a record. To flatten a portion of an input message by converting multiple records into a single record, use the Value Mapping (Flattening) Functoid.

The following figure shows a map with the Value Mapping functoid used to change the attributes of a field into the attributes of a record.

Value Mapping Functoid Map

The following code shows an input instance message in which pairs of names and values are assigned to Name and Value attributes.

<ns0:Root xmlns:ns0="http://ValueMapping.WeatherIn">  
    <Record>  
        <Field Name="WindSpeed" Value="5"/>   
        <Field Name="Temperature" Value="20" />  
    </Record>  
    <Record>  
        <Field Name="WindSpeed" Value="15" />  
        <Field Name="Temperature" Value="18" />  
    </Record>  
</ns0:Root>  

The preceding map can convert this message into one in which the values are assigned to attributes with the corresponding names in separate records.

<ns0:Root xmlns:ns0="http://ValueMapping.WeatherOut">  
    <Record WindSpeed="5"/>  
    <Record Temperature="20"/>  
    <Record WindSpeed="15"/>  
    <Record Temperature="18"/>  
</ns0:Root>  

The Equal functoids test the values of the Name attribute. The first Equal functoid tests for the value of Name being "WindSpeed." When the Name is "WindSpeed," the first Equal functoid returns True. This, in turn, allows the Value Mapping functoid to set the value of the WindSpeed attribute in the output instance message.

Suppressing the Creation of Empty Tags

To suppress empty tags, use the Value Mapping functoid to control if a tag gets created or not. If the value is evaluated to true, the destination field will be created; otherwise the destination field will not be created. In a looping scenario, use a logical functoid and connect it to the destination record or field. If the condition is evaluated to false, the tag will not be created. For an example, see Conditional Looping.

Forcing the Creation of Empty Tags

To force empty tags to be created, you can add a value in the Value property of the destination field or link a Concatenate functoid to the destination field. In BizTalk Server, it is possible to force the generation of empty tags by selecting the "<empty>" value in the Value property of the destination field. In this case the field will be created with the empty value.

See Also

Value Mapping (Flattening) Functoid
How to Add Value Mapping Functoids to a Map
Advanced Functoids