Use the Ne parameter to expose refinement dimension values.

Refinement dimension values are only returned with a valid navigation query. Therefore the N (Navigation) parameter is required for any request that will render navigation refinements. The other parameter required in most cases to render navigation refinements is the Ne (Exposed Refinements) parameter.

The Ne parameter specifies which dimension, out of all valid dimensions returned with a Navigation query, should return actual refinement dimension values. Note that only the top-level refinement dimension values are returned. If a dimension value is a parent, you can also use the Ne parameter with that dimension value and return its child dimension values (again, only the top-level child dimension values are returned).

Keep in mind that the Ne parameter is an optional query parameter. The default query (where Ne is not used) is intended to improve computational performance of the MDEX Engine, as well as reduce the resulting object and final rendered page sizes.

For example, in a simple dataset, the query:

N=0

will return three dimensions (Wine Type, Year, and Score) but no refinement dimension values. This is faster for the MDEX Engine to compute, and returns only three root dimension values.

However, the query:

N=0&Ne=6

(where 6 is the root dimension value ID for the Wine Type dimension) will return all three dimensions, as well as the top-level refinement dimension values for the Wine Type dimension (such as Red, White, and Other). This is slightly more expensive for the MDEX Engine to compute, and returns the three root dimension values (Wine Type, Year, and Score) as well as the top-level refinement dimension values for Wine Type, but is necessary for selecting a valid refinement.

A more advanced query option does not require the Ne parameter and returns all the top-level dimension value refinements for all dimensions (instead of a single dimension). This option involves the use of the ENEQuery.setNavAllRefinements() method (Java) or the ENEQuery.NavAllRefinements property (.NET). If an application sets this call to true, the query:

N=0

will return three dimensions (Wine Type, Year, and Score) as well as all valid top-level refinement dimension values for each of these dimensions (Red, White, Other for Wine Type; 1999, 2001, 2003 for Year; and 70-80, 80-90, 90-100 for Score).

This is the equivalent of the query:

N=0&Ne=6+2+9

(where 6, 2, and 9 are the root dimension value IDs for the three dimensions). This is the most expensive type of query for the MDEX Engine to compute, and returns three root dimension values as well as the nine top-level refinement dimension values, creating a larger network and page size strain. This method, however, is effective for creating custom navigation solutions that require all possible refinement dimension values to be displayed at all times.