Here are some technical essentials to start using the API
The base URL for the API is cloud.europeana.eu/api
To use the API one needs a user. Obtain one from the Europeana Cloud team.
The part of the Tutorial below gives examples and demonstrates the API calls using the popular command line utility cURL for submitting HTTP requests. One can use other tools to submit HTTP requests if desired.
In the future we'll also provide convenient client-side libraries in popular languages, such as Java.
In the examples below user credentials are provided using the --user parameter
Data Providers
Each piece of data uploaded to Europeana Cloud has to be owned by a data provider. You can manage the data providers - create or update them - using the API. Let's start with creating one. This is done using the /data-providers method.
Creation
In order to create a data provider you need to use this request. You need to provide a unique identifier for the provider in the providerId parameter. You can specify additional properties and send them as JSON in data block:
curl -X POST -H "Content-Type: application/json" --user user:password -d '{
"organisationWebsiteURL": "http://www.man.poznan.pl",
"organisationWebsite": "Poznańskie Centrum Superkomputerowo - Sieciowe Afiliowane przy Instytucie Chemii Bioorganicznej PAN",
"officialAddress" : "ul. Jana Pawła II 10, Poznań",
"digitalLibraryURL" : "http://lib.psnc.pl/dlibra",
"digitalLibraryWebsite": "Repozytorium Instytucjonalne",
"organisationName": "Poznańskie Centrum Superkomputerowo - Sieciowe Afiliowane przy Instytucie Chemii Bioorganicznej PAN",
"remarks": "Integracja i rozwój infrastruktury informatycznej nauki",
"contactPerson": "office@man.poznan.pl"
}' -i https://cloud.europeana.eu/api/data-providers?providerId=PSNC
If the provider was created successfully you will get a response with HTTP code 200. You can use the GET method on the same endpoint to make sure that the system returns information about the data provider, when queried by its id:
curl -X GET -H "Accept: application/json" --user user:password -i https://cloud.europeana.eu/api/data-providers/PSNC
The response should look like this:
{
"active":true,
"id":"PSNC",
"partitionKey":2465528,
"properties":{
"contactPerson":"office@man.poznan.pl",
"digitalLibraryURL":"http://lib.psnc.pl/dlibra",
"digitalLibraryWebsite":"Repozytorium Instytucjonalne",
"officialAddress":"ul. Jana Pawła II 10, Poznań",
"organisationName":"Poznańskie Centrum Superkomputerowo - Sieciowe Afiliowane przy Instytucie Chemii Bioorganicznej PAN",
"organisationWebsite":"Poznańskie Centrum Superkomputerowo - Sieciowe Afiliowane przy Instytucie Chemii Bioorganicznej PAN",
"organisationWebsiteURL":"http://www.man.poznan.pl",
"remarks":"Integracja i rozwój infrastruktury informatycznej nauki"
}
}
Identifiers
Creation
Every record has a unique identifier in Europeana Cloud. We call these identifiers "global". A record can also have an identifier in its original system; these identifiers are referred to as “local”.
Prior to uploading data to a record, the system needs to generate its global identifier and map it to the local one. You can do this by making this request.
curl -X POST --user user:password -i https://cloud.europeana.eu/api/cloudIds?providerId=PSNC\&recordId=exampleLocalRecord
The response will contain the mapping between the local record and the newly created identifier X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ:
<?xml version="1.0" encoding="UTF-8"?>
<cloudId>
<id>X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ</id>
<localId>
<providerId>PSNC</providerId>
<recordId>exampleLocalRecord</recordId>
</localId>
</cloudId>
curl -X POST --user user:password https://cloud.europeana.eu/api/cloudIds?providerId=exampleProvider
The newly created global identifier and a local one can be found in the response:
<?xml version="1.0" encoding="UTF-8"?>
<cloudId>
<id>745XTNGBTQBVVFFZ7XF5QETU7ECIUGHKUXBJ3DNRIN3WCKRPOVVQ</id>
<localId>
<providerId>PSNC</providerId>
<recordId>4TIRTYXNTQ2LNDWWVDKMK6TJJMJJM3I6WO4IBIDB6ORYXQB5TZIQ</recordId>
</localId>
</cloudId>
Listing
You can browse all the global ids associated with a specific data provider using the /cloudIds REST endpoint:
curl -X GET -H "Accept: application/json" --user user:password -i https://cloud.europeana.eu/api/data-providers/PSNC/cloudIds
In the response we should get a list of all cloud identifiers assigned to our provider.
{
"results":[
{
"type":"cloudId",
"id":"745XTNGBTQBVVFFZ7XF5QETU7ECIUGHKUXBJ3DNRIN3WCKRPOVVQ",
"localId":{
"providerId":"PSNC",
"recordId":"4TIRTYXNTQ2LNDWWVDKMK6TJJMJJM3I6WO4IBIDB6ORYXQB5TZIQ"
}
},
{
"type":"cloudId",
"id":"X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ",
"localId":{
"providerId":"PSNC",
"recordId":"exampleLocalRecord"
}
}
]
}
Now you are ready to fill Europeana Cloud with some data.
Records, Representations and Files
A record is the central entity of the storage system. It has a global identifier and and consists of several representations.
Representations
Lets get back to our example in the Data Model section. Say that you want to create a record out of the three files you have. Each one will be stored in a different representation. Creating new representations is done using the /records REST endpoint:
curl -X POST -H "Accept: application/json" --user user:password -H "Content-Type: application/x-www-form-urlencoded" -d 'providerId=PSNC' -i https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/TIFF curl -X POST -H "Accept: application/json" --user user:password -H "Content-Type: application/x-www-form-urlencoded" -d 'providerId=PSNC' -i https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/thumbnail curl -X POST -H "Accept: application/json" --user user:password -H "Content-Type: application/x-www-form-urlencoded" -d 'providerId=PSNC' -i https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/EDM
When successful, the response will have HTTP status code 201 (Created). Note that when a new representation is created, it is automatically assigned a new version. This new version can be reached directly using a URL which is returned in the location field of the response header. The URL will be of the following format:
https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/thumbnail/versions/cd9f0050-3dea-11e6-b03d-fa163e8d4ae3
Subsequent versions of a representation can be created further in the future, for example to reflect ongoing work on a file.
Files and Versions
You just created metadata entries for your data representations. Now it’s time to attach real data to them. For this the /versions REST endpoint is used. For example, to add a thumbnail file to a previously created representation thumbnail:
curl -X POST --user user:password -H "Content-Type: multipart/form-data" -F "mimeType=application/png" -F "data=@thumbnail.png" https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/thumbnail/versions/cd9f0050-3dea-11e6-b03d-fa163e8d4ae3/files
URI of the newly added file will be returned in the location field of the response header:
https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/thumbnail/versions/cd9f0050-3dea-11e6-b03d-fa163e8d4ae3/files/1df7a491-8d8a-4180-9eb0-cd18c52a4b81
You can add many files to a version.
The newly created version is a temporary one, which means it can be removed. To make a version persistent, you can use the /persist call:
curl -X POST --user user:password -i https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/thumbnail/versions/cd9f0050-3dea-11e6-b03d-fa163e8d4ae3/persist
A successful call will return 201 HTTP Code.
Deletion
Versions can be deleted using the DELETE call as follows:
curl -X DELETE --user user:password https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/thumbnail/versions/cd9f0050-3dea-11e6-b03d-fa163e8d4ae3/
You can only delete a temporary version of a representation. If you will try to remove a persistent version you will get HTTP status code 405 (Not Allowed).
Datasets
Datasets in Europeana Cloud are a way to group records for thematic or operational reasons. One record can belong to many datasets.
Creation
To create a new dataset, use the /dataset call where you specify the name of the dataset.
curl -X POST --user user:password -H "Content-Type: application/x-www-form-urlencoded" -d 'dataSetId=exampleDataSet' -i https://cloud.europeana.eu/api/data-providers/PSNC/data-sets
Modification
Having created one, you can assign your representation versions to this dataset. To do this use the /assignments call providing the global id, the representation name and the version identifier. If you don't provide the version identifier parameter, the latest persistent version will be assigned to data set.
curl -X POST --user user:password -H "Content-Type: application/x-www-form-urlencoded" -d 'cloudId=X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ&representationName=thumbnail&version=cd9f0050-3dea-11e6-b03d-fa163e8d4ae3' -i https://cloud.europeana.eu/api/data-providers/PSNC/data-sets/exampleDataSet/assignments
To remove a representation version from a dataset, use the /assignments DELETE method when you specify the dataset and representation:
curl -X DELETE --user user:password -H "Content-Type: application/x-www-form-urlencoded" -i https://cloud.europeana.eu/api/data-providers/PSNC/data-sets/exampleDataSet/assignments?cloudId=X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ\&representationName=thumbnail
Listing
To view the content of a dataset, use the /data-sets REST endpoint when providing the data provider id and the dataset id.
curl -X GET -H "Accept: application/xml" --user user:password -i https://cloud.europeana.eu/api/data-providers/PSNC/data-sets/exampleDataSet/
Deletion
To delete the dataset use the /data-sets REST endpoint when providing the data provider id and the dataset id.
curl -X DELETE -H "Accept: application/json" --user user:password -i https://cloud.europeana.eu/api/data-providers/PSNC/data-sets/exampleDataSet/
Permissions
Permission Granularity
In Europeana Cloud access to data entities is governed by permissions assigned to these entities. The way these permissions represent our policies on access and rights will be based on the general principles listed in the Europeana Cloud Access Framework.
In the current version access is managed on the level of files. That means that data owners can grant or revoke access to files owned by them. In future versions we will consider extending permission management also to higher levels: representations, records or datasets.
Using Permissions
Taking our example, assume that you want to make your thumbnail files publicly available. For this use the /permit REST call to to change permissions for thumbnail representations of your records.
curl -X POST --user user:password -i https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/thumbnail/versions/cd9f0050-3dea-11e6-b03d-fa163e8d4ae3/permit
If you want to give permissions to another user user:
curl -X POST --user user:password https://cloud.europeana.eu/api/records/X67WPA7NGCZUKLACPWU3BORRGQUWTKSZNZDICEGZS6IXTRMINOIQ/representations/thumbnail/versions/cd9f0050-3dea-11e6-b03d-fa163e8d4ae3/permissions/permission/users/anotherUser
In the URL above you should replace 'permission' with one of the values: read, write, delete, administration, all. 'anotherUser' should be replaced with a username.
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 TIFF representation 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.
Just remember that a file will not be accessible until you make its representation persistent.
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.
Future Work and Contact
Europeana Cloud is now in its alpha phase. During the remainder of the project we’ll improve the platform and the API based on the feedback from the community.
We welcome your feedback. Please write to pavel.kats at europeana.eu.