The PMDL that describes Core Commerce promotions discount rules is relatively simple. The PMDL DTD is located in the DCS module at /atg/dtds/pmdl/pmdl_1.0.dtd. The DTD defines the following to use in your PCML rules:

The PMDL DTD contains the following elements:

Pricing-Model Element

The root tag for the PMDL.

Offer Element

Every pricing-model element requires one offer element. The offer includes one or more discount-structure elements, which contain detailed information about the discount and its target. The offer is evaluated by the evaluateTarget method.

You can include more than one discount-structure element in an offer; this allows you to wrap multiple discounts in a single promotion (note that this is not supported in Merchandising, but you can build a custom template with this functionality).

If you have multiple discount structures within a single item promotion, you can specify the filter-collection-name attribute of the offer; this ensures that once a given item has been marked to receive a discount, it cannot receive a discount from any other discount-structures. If filter-collection-name is not set, filtering does not take place, and a given commerce item can be the target for more than one discount. The filter-collection-name should match the iterator element’s collection-name attribute, which is normally set to items. Filtering is not required for single discount structures, or for non-item-based promotions.

Qualifier Element

Every pricing-model element requires one qualifier element. The element is the root tag for the condition part of the promotion.

Target Element

Your discount structure should not include a target element if the promotion is for orders or shipping; only item discounts include target as part of the discount-structure. The target specifies the rule for selecting the items to be discounted.

Discount-Structure Element

The discount-structure element has the following attributes:

A discount-structure element can also include discount-detail elements.

Discount-Detail Element

This element is optional, and is used for complex discount types. For example, in a tiered discount, each band is represented by a discount-detail element. In this case, a discount-detail element would include one or more attribute elements that describe the band. For example, the XML representation of a band where buying 5 or more items gives the customer 10% off might look like the following:

<attribute name="band" value="5"/>
<attribute name="adjuster" value="10"/>

Attribute Element

The attribute element allows you to add generic name/value pairs to parent tags, similar to the process used to extend a Core Commerce repository. During PMDL parsing, the attributes and their values are placed in an attribute Map.

Iterator Element

Iterators are evaluation beans that sort a collection of items, then evaluate each item against one or more sub-expressions. It returns those items that match the sub-expressions.

The iterator element allows you to create custom iterators. Your new iterator element must include a name attribute that is unique across the PMDL.

An iterator element can have the following attributes and sub-elements:

Quantifier Element

Quantifiers are evaluation beans that evaluate a collection of items against one or more sub-expressions. It returns true or false, depending on the quantity of items that match the sub-expressions.

The quantifier element allows you to create custom quantifiers. Your new quantifier element must include a name attribute that is unique across the PMDL.

A quantifier element can have the following attributes and sub-elements:

Operator Element

Operators are evaluation beans that return true or false based on the Boolean results from their sub-expressions.

The operator element allows you to create custom operators. Your new operator element must include a name attribute that is unique across the PMDL.

An operator element can specify any number of attribute sub-elements and operates on at least one comparator, operator or quantifier.

Comparator Element

Comparators are evaluation beans that return true or false depending on the values of their sub-expressions.

The comparator element allows you to create custom comparators. Your new comparator element must include a name attribute that is unique across the PMDL. A comparator element can specify any number of attribute sub-elements and must specify at least one value or array name.

Comparators evaluate using one or more sub-expressions. For example:

<comparator name="isoneof">
  <value>item.auxiliaryData.productId</value>
  <constant>
    <data-type>java.lang.String</data-type>
   <string-value>xprod2147</string-value>
    <string-value>xprod2163</string-value>
  </constant>
</comparator>

Comparators can also compare two value elements, and custom comparators could include any number of value or constant elements.

Value and String-Value Elements

The value element returns the value of a property of the commerce item being evaluated. For example:

<value>item.auxiliaryData.productId</value>

To represent strings, use a string-value element. For example:

<string-value>ManufacturerA</string-value>

To represent a comma-separated list of strings, use multiple string-value elements. For example, to represent “ManufacturerA, ManufacturerB” use the following:

<string-value>ManufacturerA</string-value>
<string-value>ManufacturerB</string-value>

Constant Element

The constant element returns a constant value against which other values can be compared. For example:

<constant>
  <data-type>java.lang.String</data-type>
  <string-value>xprod2147</string-value>
</constant>

Group-Iterator Element

The group-iterator element, which is similar to the iterator element, returns a group of items for discounts. It uses the every-group and up-to-and-including-group iterators.

When creating a new group-iterator element you must include a name attribute that is unique across the PMDL.

The following is an example of a group-iterator:

<group-iterator name="every-group">
  <anded-union>
    <iterator name="next" number="1" sort-by="priceInfo.listPrice"
        sort-order="descending">
      <collection-name>items</collection-name>
      <element-name>item</element-name>
      <aggregator name="quantity" operation="total"/>
      <equals><value>item.catalogRefId</value>
        <constant>
          <data-type>java.lang.String</data-type>
          <string-value>sku40105</string-value>
        </constant>
      </equals>
    </iterator>
    <iterator name="next" number="1" sort-by="priceInfo.listPrice"
        sort-order="descending">
      <collection-name>items</collection-name>
      <element-name>item</element-name>
      <aggregator name="quantity" operation="total"/>
      <equals><value>item.catalogRefId</value>
        <constant>
          <data-type>java.lang.String</data-type>
          <string-value>sku40109</string-value>
        </constant>
      </equals>
    </iterator>
  </anded-union>
</group-iterator>