Axiell generic Media Server plugin

Generic Media Server plugin

From 3.4.1.1928, a new generic Media Server plugin has been implemented that is capable of passing through requests to different external media storage/retrieval services, using the mapping of the arguments passed to the getcontent command to a service URL. Assumptions for this to function:

• The external service URL supports the HEAD request which is used to determine the content type of the requested media.
• The requested media is returned by the external service as a byte stream.

Configuration of this new plugin is done like this:

<imageServerConfiguration name="generic">
    <servertype>FileSystem</servertype>
    <path>C:\Data\Projects\model5.0\images</path>
    <ImagePlugin type="Axiell.GenericService.Plugin.GenericPlugin, Axiell.GenericService.Plugin">
      <ServiceUrl>http://localhost/ImageServer/wwwopac.ashx?command=getcontent&server=generic&value=%value%</ServiceUrl>
      <AccessToken>9A722EF89-50A5-4045-B1115-A99B130D6092</AccessToken>
    </ImagePlugin>
  </imageServerConfiguration>

The ServiceUrl element holds the external service URL with the place holder elements between % characters. In the example above, the %value% place holder means that the incoming WebAPI getcontentrequest has a value= argument, and the value of that argument is placed in the ServiceUrl. All arguments passed in are accessible and can be used to form the new value of the ServiceUrl to be called, so from the following getcontent call:

https://server1.ourdomain.com/Azure/wwwopac.ashx?command=getcontent&server=azure&value=IMG_6936.JPG&height=200&width=200

the following placeholders can be used (also listed are the values referenced by the placeholders)

Placeholder - Value

%command% - getcontent

%server% - azure

%value% - IMG_6936.JPG

%height% - 200

%width% - 200

Any custom argument you add to the getcontent call can also be used. So something like:

https://server1.ourdomain.com/Azure/wwwopac.ashx?command=getcontent&server=azure&value=IMG_6936.JPG&source=Axiell

gives you the option to use a %source% placeholder in your ServiceUrl which will then be replaced with the value Axiell before calling the URL.

If an access token for the external service is needed you can specify that in the AccessToken node in the plugin configuration section and that will then be used as a Bearer token on the request to the external service.

Support for the HEAD request for the Axiell WebAPI has been added too. You can do a HEAD request with the getcontent call which will only return the header info with the content type and not the image itself: the body will be empty. With a normal GET request you will also get the media itself.

Support for default values

From 3.5.1.2277, the generic Media Server plugin offers support for default values. This comes in handy if sometimes a different value for a call parameter needs to be provided while most often a default value should be used if that different value is not available. A use case would be when you would gradually like to move your system from local storage of media files to a DAMS. The local storage would then be the default server while only if a certain value in a particular record field is present, the DAMS would have to be the server.

For this, an (optional) list of default parameters can now be specified underneath the <ImagePlugin> node. A default parameter and its value will be applied to the configured URL when either the parameter is missing from the configured URL of when the parameter is empty in the configured URL.

Below you can see an example configuration in which the server parameter in the configured ServiceUrl has custom placeholder called %altserver%. When the caller replaces it with an actual image server name in the query, then that image server will be used: if not, then the server=images argument will be applied and the images image server will be used:

<imageServerConfiguration name="generic">
    <servertype>FileSystem</servertype>
    <path>C:\Data\Projects\model5.0\images</path>
    <ImagePlugin type="Axiell.GenericService.Plugin.GenericPlugin, Axiell.GenericService.Plugin">
      <ServiceUrl>http://localhost/ImageServer/wwwopac.ashx?command=getcontent&server=%altserver%&value=%value%</ServiceUrl>
      <DefaultParameters>
         <DefaultParameter key="server" value="images" />
      </DefaultParameters>
      <AccessToken>9A722EF89-50A5-4045-B1115-A99B130D6092</AccessToken>
    </ImagePlugin>
  </imageServerConfiguration>

An example of a getcontent call using an image server called myaltserver would be the following:

https://server1.ourdomain.com/wwwopac.ashx?command=getcontent&server=generic&altserver=myaltserver&value=IMG_6936.JPG&height=200&width=200