When the isAutoGen property of a JSON attribute is set to true ("isAutoGen" : true), the name of the attribute becomes the name of an the automatically generated dimension. This rule applies only to attributes with the parameter "ecr:type" : "dimension".

Dimension values for flat dimensions, however, are not named explicitly in the JSON documents that configure the dimensions. Instead, the "sourcePropertyNames" attribute parameter specifies the names of one or more source record properties, each of whose values will be used as a dimension value in the flat dimension.

For example, the following JSON attribute specifies that the value of every property in your source records named video_capability will become a dimension value of a flat dimension named camera.video_capability:

"camera.video_capability" : {
  "displayOrder" : 7,
  "ecr:type" : "dimension",
  "isAutogen" : true,
  "sourcePropertyNames" : [ "video_capability" ]
  },

Thus, if three different source records each have a property named video_capability, set to Slow, Regular, and Fast respectively, the flat dimension named camera.video_capability will contain dimension values named Slow, Regular, and Fast.

Also note that a source record can have different properties, each of which matches the sourcePropertyNames value in a different dimension. Thus, a single Endeca record might be tagged to the dimension value green in the dimension Color, to Camera in the dimension category, and to $150 - $200 in the dimension Prices.