com.avoka.tm.util.ObjectMapper

public class ObjectMapper extends Object

This class provides XML Document to Object mapping support.

Transact supports marshalling data between Form XML Documents and Groovy Value Objects using the ObjectMapper class. Where possible we recommend you use the ObjectMapper for mashalling data, rather the doing this by hand which is tedious and often error prone.

The ObjectMapper supports two use cases:

creating an Groovy object graph from an XML document
updating an XML document based on an Groovy object graph

ObjectMapper Configuration

The ObjectMapper has a number of default configurations, which can be changed with the appropriate setter methods:

strictMode - specified whether a missing Object field for a Document tag will throw an exception (default value true).
Note: Disabling strict mode may bring some unpredictable behavior especially with repeats when there is total mismatch of the object and XML structure. The result could be wrong mapping of XML tags and values to objects.
mappingStrategy - specifies XML tag name to object mapping strategy (default value CamelUpperCase). For example '<FirstName>' XML tag will map to Object's field 'firstName'.
dateFormat - the date time mashalling format (default value of 'yyyy-MM-dd').

The example below set mapping strategy to handle XML Document's tag of type 'lowerCamelCase', date format 'yyyy/dd/MM' and switch off the strict mapping mode (ignore unknown XML tag and not throw an exception).

 import com.avoka.tm.util.*
 import java.text.SimpleDateFormat

 new ObjectMapper()
    .setMappingStrategy(MappingStrategy.LOWER_CAMEL_CASE)
    .setDateFormat(new SimpleDateFormat("yyyy/dd/MM"))
    .setStrictMode(false)

Groovy Examples

Please find the ObjectMapper examples below using the following Groovy value object classes.

 package com.maguire.vo

 import java.util.*

 class Person {
     String firstName
     String lastName
     String email
     Address currentAddress
     List<Address> previousAddresses
 }

 class Address {
     String line1
     String city
     Integer postCode
     String country
 }

The corresponding XML elements for these classes are provided below

 <Person>
     <FirstName/>
     <LastName/>
     <Email/>
     <CurrentAddress>
         <Line1/>
         <City/>
         <PostCode/>
         <Country/>
     </CurrentAddress>
     <PreviousAddresses>
         <Address>
             <Line1/>
             <City/>
             <PostCode/>
             <Country/>
         </Address>
     </PreviousAddresses>
 </Person>

Creating an Object Graph

This Groovy example creates Person object from Document's xpath.

 import com.avoka.tm.util.*
 import com.maguire.vo.*

 Person person = new ObjectMapper()
    .setDoc(param.appDoc)
    .setFormXPath('/Person')
    .create(Person.class)

An example source XML document is provided below. In this example the XML repeating PreviousAddresses elements will be mapped into the Person classes List<Address> previousAddresses field.

 <?xml version="1.0"?>
 <AvokaSmartForm>
     <Person>
         <FirstName>John</FirstName>
         <LastName>Smith</LastName>
         <Email>jsmith@maguire.com</Email/>
         <CurrentAddress>
             <Line1>12 Peterson Avenue</Line1>
             <City>Hope Town</City>
             <PostCode>4275</PostCode>
             <Country/>
         </CurrentAddress>
         <PreviousAddresses>
             <Address>
                 <Line1>30 Peace Street</Line1>
                 <City>Hope Town</City>
                 <PostCode>4276</PostCode>
                 <Country/>
             </Address>
             <Address>
                 <Line1>Unit 3/65 Dunkley Avenue</Line1>
                 <City>Melville</City>
                 <PostCode>5621</PostCode>
                 <Country>Australia<Country>
             </Address>
         </PreviousAddresses>
     </Person>
 <AvokaSmartForm>

Repeats Support

This Groovy example shows how to map object's repeat field with XML tag.

In order to enable repeat support the repeat field (e.g. List<Address> previousAddresses) needs those two annotations:

JacksonXmlElementWrapper, which allows specifying XML element to use for wrapping, and
JacksonXmlProperty, which allows specifying XML local element name for a property

 package com.maguire.vo

 import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlElementWrapper;
 import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlProperty;

 import java.util.*

 class Person {
     String firstName
     String lastName
     String email
     Address currentAddress

     @JacksonXmlElementWrapper(localName = "PreviousAddresses")
     @JacksonXmlProperty(localName = "Address")
     List<Address> previousAddresses
 }

 class Address {
     String line1
     String city
     Integer postCode
     String country
 }

An example source XML document is provided below.

In this example, the XML repeating Address elements of the wrapper PreviousAddresses element will be mapped into the Person classes List<Address> previousAddresses field and each child node Address will create Address object and add to the List<Address> previousAddresses.

 <?xml version="1.0"?>
 <AvokaSmartForm>
     <Person>
         <FirstName>John</FirstName>
         <LastName>Smith</LastName>
         <Email>jsmith@maguire.com</Email/>
         <CurrentAddress>
             <Line1>12 Peterson Avenue</Line1>
             <City>Hope Town</City>
             <PostCode>4275</PostCode>
             <Country/>
         </CurrentAddress>
         <PreviousAddresses>
             <Address>
                 <Line1>30 Peace Street</Line1>
                 <City>Hope Town</City>
                 <PostCode>4276</PostCode>
                 <Country/>
             </Address>
             <Address>
                 <Line1>Unit 3/65 Dunkley Avenue</Line1>
                 <City>Melville</City>
                 <PostCode>5621</PostCode>
                 <Country>Australia<Country>
             </Address>
         </PreviousAddresses>
     </Person>
 <AvokaSmartForm>

Important remarks when working with repeats:

Root element must be a POJO but can not be a repeat
Refrain from disabling strict mode as it may bring some unpredictable behavior especially when there is total mismatch of the object and XML structure. The result could be wrong mapping of XML tags and values to objects.

Updating XML Document

This Groovy example stores Person object in the Document using the XPath '/Person'. Please note the ObjecMapper will automatically set the appropriate root XPath based on the type of document.

 import com.avoka.tm.util.*
 import com.maguire.vo.*

 Person person = new Person()
 person.firstName = 'Peter'

 new ObjectMapper()
    .setObject(person)
    .setFormXPath('/Person')
    .update(param.appDoc)

Object Map Field Support

Support is also provided for Object map fields. This feature is very useful for mapping adhoc XML elements into a class Object.

The example below has added Map customProps field.

 package com.maguire.vo

 import java.util.*

 class Person {
     String firstName
     String lastName
     String emailAddress
     Map<String, String> customProps
 }

XML of Primary Applicant's 'customProps' could be properties like account number, tax number, etc.

 <Person>
     <CustomProps>
         <accountNumber>12345</accountNumber>
         <taxNumber>67890</taxNumber>
     </CustomProps>
 </Person>

 import com.avoka.tm.util.*
 import com.maguire.vo.*

 Person person = new ObjectMapper()
    .setDoc(param.appDoc)
    .setFormXPath('/Person')
    .create(Person.class)

 String accountNumber = person.customProps.get('accountNumber')

 // May put new property value and use update...

Transact Function Example

The function example below is creating an new Applicant object graph from the application document (param.appDoc).

The example then updating the applicants address details, and then write the object graph back into the application document. Finally in the FormFuncResult result we turn on the option to return the form XML document back to the form. The JavaScript form application will then update its model with the new address details and display them to the user.

 package com.maguire.svc;

 import com.avoka.tm.func.*
 import com.avoka.tm.svc.*
 import com.avoka.tm.util.*
 import com.avoka.tm.vo.*
 import com.maguire.vo.*

 import javax.servlet.http.*

 public class Controller {

     // Injected at runtime
     public Logger logger

     FuncResult invoke(FuncParam param) {

         // Marshal formData into applicant object VO graph
         Person applicant = new ObjectMapper()
             .setDoc(param.appDoc)
             .setFormXPath("/Applicant")
             .create(Person.class)

         logger.info("Applicant: " + applicant)

         // Add applicant address information
         applicant.currentAddress = new Address()
         applicant.currentAddress.line1 = "61 Main Street"
         applicant.currentAddress.city = "Avalon"
         applicant.currentAddress.postCode = "2107"
         applicant.currentAddress.country = "Australia"

         // Update formData with updated application object
         new ObjectMapper()
             .setObject(applicant)
             .setFormXPath("/Applicant")
             .update(param.appDoc)

         FormFuncResult result = new FormFuncResult()

         // Specify formData to be returned to form
         result.includeFormData = true

         return result
      }
 }

The examples XML response document is provided below. Note in this example we have mapped the Person objects into the documents Applicant element.

 <?xml version="1.0"?>
 <AvokaSmartForm>
     <Applicant>
         <FirstName>John</FirstName>
         <LastName>Smith</LastName>
         <Email>jsmith@maguire.com</Email/>
         <CurrentAddress>
             <Line1>61 Main Street</Line1>
             <City>Avalon</City>
             <PostCode>2107</PostCode>
             <Country>Australia</Country>
         </CurrentAddress>
         <PreviousAddresses/>
     </Applicant>
 <AvokaSmartForm>

Since:: 17.10.0

Nested Class Summary

Nested Classes

Modifier and Type

Class

Description

static enum

ObjectMapper.MappingStrategy

Naming convention mapping strategy enumeration.
Constructor Summary

Constructors

Constructor

Description

ObjectMapper()
Method Summary

Modifier and Type

Method

Description

<T> T

create(Class<T> type)

Create object of the generic T type.

ObjectMapper

setDateFormat(DateFormat dateFormat)

Set date format.

ObjectMapper

setDoc(Document document)

Set document object to create object from.

ObjectMapper

setFormXPath(String xpath)

Set the Form XPath parameter.

ObjectMapper

setMappingStrategy(ObjectMapper.MappingStrategy mappingStrategy)

Set mapping strategy.

ObjectMapper

setObject(Object object)

Set object to update.

ObjectMapper

setStrictMode(boolean strict)

Set strict mapping mode.

ObjectMapper

setXPath(String xpath)

Set the explicit XPath parameter.

void

update(Document document)

Update object of the generic T type.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- ObjectMapper
  
  public ObjectMapper()

Method Details

setDateFormat

public ObjectMapper setDateFormat(DateFormat dateFormat)

Set date format. If not specified the default 'yyyy-MM-dd' date pattern will be used.

Parameters:

dateFormat - date format

Returns:

object mapper object
setDoc

public ObjectMapper setDoc(Document document)

Set document object to create object from.

Parameters:

document - document object to create object from

Returns:

object mapper object
setMappingStrategy

public ObjectMapper setMappingStrategy(ObjectMapper.MappingStrategy mappingStrategy)

Set mapping strategy.

Parameters:

mappingStrategy - mapping strategy

Returns:

object mapper object
setObject

public ObjectMapper setObject(Object object)

Set object to update.

Parameters:

object - object to update

Returns:

object mapper object
setStrictMode

public ObjectMapper setStrictMode(boolean strict)

Set strict mapping mode. If set to false, the mapper will ignore unknown XML/class properties. By default this flag is set to true.

Parameters:

strict - strict mapping flag

Returns:

object mapper object

setFormXPath

public ObjectMapper setFormXPath(String xpath)

Set the Form XPath parameter. Any relative XPath specified will be prepended to create an absolute path.

For documents with a <AvokaSmartForm> root node XPath expansion examples are provided below:

FormXPath	Expanded XPath
Applicant	/AvokaSmartForm/Applicant
/Applicant	/AvokaSmartForm/Applicant
AvokaSmartForm/Applicant	/AvokaSmartForm/Applicant
/AvokaSmartForm/Applicant	/AvokaSmartForm/Applicant

For documents with a <Root> root node XPath expansion examples are provided below:

FormXPath	Expanded XPath
Applicant	/Root/AvokaSmartForm/Applicant
/Applicant	/Root/AvokaSmartForm/Applicant
AvokaSmartForm/Applicant	/Root/AvokaSmartForm/Applicant
/AvokaSmartForm/Applicant	/Root/AvokaSmartForm/Applicant

Please note you cannot specify a // search XPath as this becomes ambiguous when setting object values back into the document.

Parameters:: xpath - xpath parameter
Returns:: object mapper object

setXPath

public ObjectMapper setXPath(String xpath)

Set the explicit XPath parameter.

Please note you cannot specify a // search XPath as this becomes ambiguous when setting object values back into the document.

Parameters:

xpath - xpath parameter

Returns:

object mapper object
create

public <T> T create(Class<T> type)

Create object of the generic T type.

Type Parameters:

T - object type that will be created

Parameters:

type - object class type to create

Returns:

object of the generic T type
update

public void update(Document document)

Update object of the generic T type.

Parameters:

document - XML document object

Class ObjectMapper

ObjectMapper Configuration

Groovy Examples

Creating an Object Graph

Repeats Support

Updating XML Document

Object Map Field Support

Transact Function Example

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Details

ObjectMapper

Method Details

setDateFormat

setDoc

setMappingStrategy

setObject

setStrictMode

setFormXPath

setXPath

create

update