Interfaces and data extraction
For the benefit of research and teaching, e-rara.ch provides various interfaces for the extraction and further use of data. This page describes the extraction of standardised metadata incl. links to digital copies (OAI-PMH), full texts, PDFs, RIS files and the possibilities relating to IIIF.
OAI interface
The OAI-PMH protocol contains six basic functions which are appended to the baseURL https://www.e-rara.ch/oai with “?verb=”:
Identify: Display general information about the OAI repository
ListSets: Information about all records available in the OAI repository
ListMetadataFormats: List of available data formats
GetRecord: Retrieve a single record using the identifier
Parameters:
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identifier: Identification number of the desired record
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metadataPrefix: Name of the data format in which the record is to be delivered. The values available for selection can be retrieved using the ListMetadataFormats command (see above).
ListRecords: Harvest records by specifying the time period (from/until) and/or record. The time is given in Coordinated Universal Time (UTC). This is the core function of OAI. It allows selective harvesting, which means that the harvester can limit their query to records that
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are from a specific catalogue and
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were created or modified in a specific time period
Parameters:
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from/until: Points in time that define the time period for selective harvesting. These can be accurate to the day (YYYY-MM-DD) or to the second (YYYY-MM-DDThh:mm:ss), depending on the OAI repository.
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set: The catalogue from which the records originate
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metadataPrefix: see above
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resumptionToken: For each query, the server returns packets each containing 10 records together with a token. This is required in each case to generate the next query.
ListIdentifiers: Returns identifiers
Parameters:
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from/until: Points in time that define the time period for selective harvesting. These can be accurate to the day (YYYY-MM-DD) or to the second (YYYY-MM-DDThh:mm:ss), depending on the OAI repository.
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set: The catalogue from which the records originate
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metadataPrefix: see above
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resumptionToken:* For each query, the server returns packets each containing 10 records together with a token. This is required in each case to generate the next query.
Examples:
Identify OAI interface
Return available sets
Return available metadata formats
Query records in oai_dc format
Query records using a token
Query a record using an identifier
Query identifiers within a specific time period
Note: There are some very extensive titles in e-rara.ch. If records of such titles are harvested in MetadataFormat=mets, the action may fail because the amount of data is simply too large and the transfer times out.
Full texts
On each title view, there is a link in the DOWNLOAD section where the full text can be downloaded if it is available. Currently, the full text is offered as plain text as well as ALTO XML.
The structure of the query is as follows:
https://www.e-rara.ch/[domain]/download/ftpack/[typ]/[VLID]
Whereby [domain] is the institution’s abbreviation (this information is not absolutely necessary). The parameter [typ] specifies whether the full text should be accessed as plain text or ALTO XML. The two possible values are “plain” or “alto”. Finally, the [VLID] of the title must be provided. This can be seen in the URL. For a machine download, it is advisable to harvest the VLIDs via OAI in a first step and read them from the records.
Examples:
www.e-rara.ch/zut/download/ftpack/plain/6341733
www.e-rara.ch/zut/download/ftpack/alto/6341733
Each title view contains a link in the DOWNLOAD section where the title can be downloaded as a PDF. If the title has been structured (this can be seen on the Content view tab), individual PDFs of the structure nodes are also available and can be downloaded under the Content view tab.
The structure of the query is as follows:
https://www.e-rara.ch/download/pdf/[VLID].pdf
The [VLID] of the title is visible in the URL in each case. For a machine download of the title PDF (not the structure node PDF), it is advisable to harvest the VLIDs via OAI in a first step and read them from the records.
RIS
Each title view contains a link in the DOWNLOAD section where the metadata can be downloaded in RIS (Research Information System) format.
The structure of the query is as follows:
https://www.e-rara.ch/[domain]/download/format/ris/[VLID]
Whereby [domain]is the institution’s abbreviation (this information is not absolutely necessary) and [VLID] is the identifier of the title. This is visible in the URL in each case. For a machine download, it is advisable to harvest the VLIDs via OAI in a first step and read them from the records.
IIIF
On each front page, in the “IIIF” section, there is a link to the IIIF manifesto. This manifest address can be used to load the title directly in an external IIIF viewer (Mirador or universal viewer).
Furthermore, it is also possible to control individual images directly via the IIIF server.
The structure of the query is as follows:
https://www.e-rara.ch/i3f/v21/[VLID]/full/0/0/default.jpg
The [VLID]is the identifier of the corresponding image and can be read from the URL when you are in the page view.
For more information on specific parameters, please refer to the documentation here: