View source for Print Template Classes

===About Print Template Classes===
Using a method defined in a [[Class]], you can manipulate the data that a Print Template processes. Here's how it works:
 
:* When a [[Print Template]] is processed, it gets its data from the [{{DOCHOST}}/javadocs/com/platform/api/TemplateContext.html TemplateContext]

:* The TemplateContext contains a HashMap for each record sent to the Print Template, indexed by an Object name (a string). The HashMap contains name/value pairs for each field in that record.

:* To a Print Template, then, a data object is simply a HashMap that is present in the  TemplateContext.

:* That object is passed to a method you define. By manipulating the HashMaps it contains, you change the data that the Print Template processes. You can even add new "objects", by adding additional HashMaps, and new "related objects", by adding ArrayLists of HashMaps.

===Coding a Method in a Print Template Class===
In a Print Template, a data reference has the form <tt>$''objectName''.''fieldname''</tt>. To access, create, or modify data in your code, you will do one or more of the following operations:
:*;Retrieve an object's HashMap from the TemplateContext: <tt>TemplateContext.get("''objectName''");</tt>

:*;Add or update a data HashMap: <tt>TemplateContext.put("''objectName''", HashMap);</tt>

:*;Get a field from data HashMap: <tt>HashMap.get("''fieldName''");</tt>
:*;Add or update a field in a data HashMap: <tt>HashMap.put("''fieldName''",''value'');</tt><br>where <tt>''value''</tt> is typically a string or a nested HashMap.

:*;Retrieve an ArrayList of related-object HashMaps from the TemplateContext: <tt>TemplateContext.get("''RelatedObjectName''");</tt>

===Configuring a Print Template to use a Specified Class and Method===
To designate the class and method to use, when creating or editing a [[Print Template]]:
# Under '''Custom Data Source''', click '''Enabled'''.
# In '''Select a Class''', choose the class that has the method you want.
# In '''Select Method''' choose the method that does the processing you want.

The methods available to choose are public methods that have the following signature:
:<syntaxhighlight lang="java" enclose="div">
doSomething(TemplateContext context, String objName, String recordId)
</syntaxhighlight>
:where:
:; [{{DOCHOST}}/javadocs/com/platform/api/TemplateContext.html <tt>com.platform.api.TemplateContext</tt>]: Is the container that the print template gets its data from.
:; <tt>String (objName)</tt>: Has the name of the object the print template was invoked on. 
:; <tt>String (recordID)</tt>: Has the ID of the record on which it was invoked.

;Considerations:
:* A class can contain multiple processing methods, so you can do all related-work in a single class.
:* Such methods generally return <tt>void</tt>, but they don't have to. Any method that takes the appropriate arguments will be listed, regardless of its return value.

===Accessing Lookup Target Records===
Data from lookup-target records is stored as a nested map. For example, to get data for the template variable <tt>$Order.customer.name</tt>:

:1. '''<tt>HashMap orderMap = TemplateContext.get("Order")</tt>'''
::  Gets the Order HashMap from the context. 

:2. '''<tt>HashMap customerMap = orderMap.get("customer")</tt>'''
::  Gets the lookup-target record for the customer field.

:3. '''<tt>String name = customerMap.get("name")</tt>''' 
::  Gets the customer's name.

===Accessing Data in Related Records===
A Print Template is always invoked on a specific record. Related-object records that look up to that record are contained in an ArrayList of HashMaps, indexed by object name. The code for obtaining and processing that kind of list looks like this:

:<syntaxhighlight lang="java" enclose="div">
public void chgData(TemplateContext context, String obj, String record)
{
    ArrayList<HashMap<String,Object>> listOfRecords =
        (ArrayList)context.get("SomeObject");
    if (listOfRecords == null) { listOfRecords = new ArrayList(); }
    for (HashMap<String,Object> currRecord : listOfRecords )
    {
	// Process the records in this for-each loop
    }		
}
</syntaxhighlight>

To create an entirely new breed of related "records", create an ArrayList of the appropriate type and add it to the TemplateContext.

===Examples===

====Changing Field Data====
This example substitutes the name of the state for its abbreviation, when processing a Customer record:
:<syntaxhighlight lang="java" enclose="div">
public void chgData(TemplateContext context, String obj, String record)
{
    HashMap customerMap = (HashMap)context.get("Customer");
    String state = customerMap.get("state").toString();
    if ( "CA".equals(state) ) { 
        customerMap.put("state","California"); 
    }
}
</syntaxhighlight>

====Example: Adding a New Field====
This example adds a new "Good Customer" field to the record. 
:<syntaxhighlight lang="java" enclose="div">
public void addData(TemplateContext context, String obj, String record)
{
    HashMap customerMap = (HashMap)context.get("Customer");
    customerMap.put("rating", "Good Customer"); }
}
</syntaxhighlight>

After that method has run, the Print Template can use the variable <tt>$Customer.rating</tt>, just as though that field was defined in the platform object.

====Example: Adding a New Object====
This code creates a new ProductSupplier "object" (as far as the Print Template is concerned), and adds it to the TenantContext (<tt>context</tt>).
:<syntaxhighlight lang="java" enclose="div">
public void addObj(TemplateContext context, String obj, String record)
{
    HashMap<String, Object> productSupplierMap = 
        new HashMap<String, Object>();
    productSupplierMap.put("supplierName", "Stuff R' Us");
    productSupplierMap.put("phone", "408-555-0987");
    context.put("ProductSupplier", productSupplierMap);
}
</syntaxhighlight>

After that method has run, the Print Template can use the variable <tt>$ProductSupplier.phone</tt>, just as though the data had originated in the platform.