Template

What are Templates?

Templates or Export Transformations format data type records into data going outside Velosimo.
They are located in the Transforms-Templates section of the platform.

Source data-type defines the type of record to be formatted. If no source data-type is defined then the Transformation will be able to format records of any data type.

Bulk source: Depending on the Transformation having the option bulk source, the variable source or sources is available representing a single record or an enumeration of records to be formatted.

A simple non bulkable JSON exporter can be defined by the following transformation:

source.to_json

If the Transformation is bulkable a little more transformation code is needed to format all the source records into a single JSON data:

if (jsons = sources.collect { |source| source.to_json[0] 
else 
"[#{jsons.join(',')}]"
end

The result of the translation execution is the value of the latest evaluated expression.

There are a set of predefined methods available on record objects that can be used for basic formats:

to_(json|xml|edi)

Every formatter method can receive options, for example:

source.to_json(pretty: true) 
source.to_xml(with_blanks: true) 
source.to_edi(field_separator: ‘+’)

In the template/exporters the variable source_data_type is a reference to the Transformation source data type.

A transformation for bulkable XML exporter can be written as
following:

if sources.count == 1 
 sources.first.to_xml 
else 
 sources.to_xml_array(root: source_data_type.slug) 
end

A transformation for bulkable JSON exporter can be written as following:

sources.first.to_json

Ruby templates

The simplest way to configure a Ruby template is by invoking the built-in format methods (to_hash, to_json, share_hash, to_xml, to_edi) on the local variable source , which represent the source record the template is being applied to. For example, for a JSON template just the following code:

source.to_json

There are some options that can be used for the build-in methods, perhaps the template should be pretty JSON formatted, or some properties must be excluded:

source.to_json(pretty: true, ignore: 'id')

For the previous example where a data type is supposed to have the properties name and items where items is an association the above code will generate a JSON like this:

{ 
	"name": "A", 
	"record": [ 
		{ 
		"name": "A1", 
		"record": 1.0 
		}, 
		{ 
		"name": "A2", 
		"record": 2.0 
		}, 
		{ 
		"name": "A3", 
		"record": 3.0 
		} 
	] 
}

The built-in format methods use the data type structure to generate the template, by default all properties are included. Of course a JSON template with completely different entries can be configured by typing the appropriated ruby code. For example:

{ 
 name: source.name, 
 count: source.items.count, 
 price: source.items.inject(0) { |s, item| s + item.pr
}

will produce the following JSON:

{ 
"name": "A", 
"count": 3, 
"price": 6.0 
}