====== Adding a CANNOT rule ======

Let’s go back to our example and add a //CANNOT// rule to the Build To Order product, to manage the conflict between two available selections. The rule that we need to define consists of not allowing customers to select a //Booklet// style for their brochure if they select a //Horizontal// orientation(1).

To create this simple rule, we will do the following:

  * From the //If customers select//… drop-down, we will pick //Horizontal//
  * We will leave the … //they must select// area empty.
  * In the … //they cannot select// area, we will choose //Booklet//.
  * We will then click on the //Add Rule(s)// button to save this new rule.

ProductCart will save the rule to the database and show a confirmation message. Click on //View Summary// next to the confirmation message to view a summary of the rules that you have applied to the Build To Order product. In our example, the summary shows the only rule that we have created so far.

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{{adding_cannot_rule.gif|}}

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You can click on //Edit// to change the rule’s settings at any time. Check the checkbox on the left side and click on //Delete Selected// if you wish to remove an existing rule. Be careful because this action cannot be undone and recreating a rule can be time consuming. Press the //Add New Rules// button to add new rules to the product.

Let’s go to the storefront and see how this rule is applied on the product configuration page. Click on //Preview configuration page// and the product configuration page will open in a new browser window. If we try to select //Horizontal// from the //Orientation// category, and then //Booklet// from the //Style// category, ProductCart shows a message alerting us that the two options cannot be selected at the same time.

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{{conflict_alert.gif|}}

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(1)This example assumes that a number of categories and items had been previously added to the Build To Order product using the product configuration page in the Control Panel. Among others //Orientation// and //Style// categories were added to the product, each containing a number of Build To Order Only items (“Horizontal” and “Vertical” for the //Orientation// category and //Spec Sheet, Bookfold, Booklet, and Tri-Fold// for the //Style// category).

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