The mediaContent item type has a mediaType property that indicates the type of binary file that the item’s url property points to. The mediaType property is an enumerated property that accepts the following values:

The mediaType property is set automatically by the /atg/content/service/MimeCategoryTyper component, which is of class atg.servlet.MimeCategoryTyper. This component uses the /atg/dynamo/servlet/pipeline/MimeTyper component to examine the filename extension of the mediaContent item’s url property and determine the corresponding MIME type. For example, if the extension is mpeg, MimeTyper returns video/mpeg as the MIME type.

Important: When a URL is created by uploading content in the Business Control Center, it does not contain the full path, but only the path that works on the server where the content was uploaded. When loading the URL values to a production server, you must modify the URL path so that it contains the full path. For information on creating media content, refer to the Merchandising Guide for Business Users.

MimeCategoryTyper then examines the MIME type returned by MimeTyper and returns one of the MIME categories listed above. For example, if the MIME type is image/jpeg or image/gif (or any other image type), MimeCategoryTyper returns Image.

MimeCategoryTyper has properties for specifying strings that it attempts to match with the MIME type to determine the MIME category:

Each of these properties is a Map in which the keys are strings used for comparison with MIME types, and the values are MIME categories. To return the appropriate MIME category, MimeCategoryTyper uses the following logic:

The MimeCategoryTyper component’s properties file includes the following:

mimeTyper=/atg/dynamo/servlet/pipeline/MimeTyper
startsWithCategories=\
        image=Image, \
        video=Video, \
        audio=Audio
endsWithCategories=\
        pdf=PDF
defaultCategory=Other

So, for example, if the MIME type is video/mpeg, the MIME category is Video; if the MIME type is application/pdf, the MIME category is PDF; and if the MIME type is application/rtf, the MIME category is Other.

Detecting Changes to the url Property

The /atg/content/service/MimeTypeCategoryListener component is responsible for determining when the url property of a mediaContent item has been set or changed, and then invoking MimeCategoryTyper to determine the new value of the item’s mediaType property. To do this, MimeTypeCategoryListener registers an atg.repository.PropertiesChangedListener on the mediaContent item descriptor.

The MimeTypeCategoryListener component’s properties file specifies the item descriptor to set the listener on, the names of the url and mediaType properties, and the MimeCategoryTyper component responsible for setting the mediaType value:

mimeCategoryTyper=/atg/content/service/MimeCategoryTyper
itemDescriptorName=mediaContent
repository=/atg/content/ContentManagementRepository
urlPropertyName=url
mimeTypeCategoryPropertyName=mediaType

When MimeTypeCategoryListener detects that the url property of a mediaContent item has changed, it invokes MimeCategoryTyper to determine the new value of the mediaType property of the item, as described above. The MimeTypeCategoryListener component is registered in the initialServices property of the /Initial component, so that it starts up automatically when the Oracle Commerce Core Platform starts up.