Friendly URLs

Sometimes it is hard for a client to get the global identifier of a record, generated version name of a representation and generated filename. On the other hand the client has got a local record identifier which is well known. The same may be in case of a filename. In order to access files without retrieving the hard to remember identifiers and names mechanism of friendly URLs was introduced. The idea behind it is to use in URLs well known values (identifiers, names, etc.) always in the same way. Here we will go through the tutorial steps using friendly URLs where it is possible.

Record

Normally when you know the cloud identifier of a record you can access it using URL like this:

https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ

If you remember from the beginning of this tutorial, this record was created for PSNC data provider together with local identifier which was exampleLocalRecord. So now we have only two values: name of the data provider (PSNC) and identifier used by this data provider (exampleLocalRecord). To get access to this record in Europeana Cloud using just these two values we can use friendly URL like this:

curl -X GET -H "Accept: application/json" --user user:password -i https://cloud.europeana.eu/api/data-providers/PSNC/records/exampleLocalRecord

Representation

Sometimes it is necessary to get access to a specific representation. Again, instead of retrieving the global identifier we can use well known values like data provider name, local record identifier and representation name. Let's display information about the TIFFrepresentation using the friendly URL:

curl -X GET -H "Accept: application/json" --user user:password -i https://cloud.europeana.eu/api/data-providers/PSNC/records/exampleLocalRecord/representations/TIFF

File

If you do not want to have files with names generated by the system there is possibility to specify the name in the insert request. We can add a file to TIFF representation and specify a name for it like this:

curl -X POST --user user:password -H "Content-Type: multipart/form-data" -F "mimeType=image/tiff" -F "data=@tiff.tiff" -F "fileName=abc" https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/TIFF/versions/27ae2a60-3ebf-11e6-b03d-fa163e8d4ae3/files

As you can see the specified filename is abc. Now we can use it to access this file in Europeana Cloud via friendly URL.

 curl -X GET -H "Accept: application/json" --user user:password -i https://cloud.europeana.eu/api/data-providers/PSNC/records/exampleLocalRecord/representations/TIFF/abc

Filename used instead of a generated one can be also much more complex. It can for example contain / characters like in the absolute path. We can take a look at the real example provided by Europeana Newspapers.

https://cloud.europeana.eu/api/data-providers/TheEuropeanLibrary/records/3000100349685/representations/presentation_images/node-2/image/NLE/???????????_??????????_?????????_=_Livländische_Gouvernements-Zeitung/1862/01/03/18620103_1-0001.jp2

As you can see the filename used here (node-2/image/NLE/???????????_??????????_?????????_=_Livländische_Gouvernements-Zeitung/1862/01/03/18620103_1-0001.jp2) is not only long with / characters but also contains unicode characters. We can also extract other well known values from this URL: data provider - TheEuropeanLibrary, local record identifier - 3000100349685, representation name - presentation_images.