Validate an XML metadata file and retrieve a list of validation errors or a successful validation message.

This tool uses the same logic as the SDC metadata harvester to check for metadata issues. Failure of any check will result in the file being rejected by the SDC when harvested from one of the USGS repositories.

Validation checks

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xml_valid

The file can be parsed, specifically by Python's standard library xml.etree.ElementTree.fromstring() function.

Issues that can cause XML parsing to fail include a newline at the beginning of the file or mismatched tags.

NOTE: A failure at this point will automatically result in all other checks showing as failed.

Error message: The file's XML is invalid.

---

title_present

The file contains a non-empty title element in the following location:

FGDC: idinfo/citation/citeinfo/title ISO: gmd:identificationInfo/gmd:MD_Data Identification/gmd:citation/gmd:CI_Citation/gmd:title/gco:CharacterString

Error message: The file is missing a title.

---

email_contact_present

The file contains a properly formatted email contact in the following location:

FGDC: metainfo/metc/cntinfo/cntemail ISO: gmd:contact/gmd:CI_ResponsibleParty/gmd:contactInfo/gmd:CI_Contact/gmd:address/gmd:CI_Address/gmd:electronicMailAddress/gco:CharacterString

We are using python-email-validator.

Error message: The file is missing a valid email contact.

---

mdate_present

The file contains a metadata date in the following location and formats:

FGDC: metainfo/metd - 20210307, 202103, 2021 ISO: gmd:dateStamp/gco:Date - 2021-03-07, 20210307, 202103, 2021

Error message: The file is missing an mdate.

---

pid_in_file

The file contains an identifier in the following location:

FGDC: idinfo/keywords/theme/themekt/themekey NOTE: themekt must have the value 'USGS Metadata Identifier' ISO: gmd:fileIdentifier/gco:CharacterString

Error message: The file is missing a PID.

---

pid_in_pir_db

The file's identifier was found in the PIR (Persistent Identifier Registry).

Error message: The PID found in the file is not registered in the PIR database.

---

doi_present

The file contains a properly formatted DOI URL. The sources are checked in the following order:

FGDC:

• 'onlink': idinfo/citation/citeinfo/onlink
• 'lworkcit': idinfo/citation/citeinfo/lworkcit/citeinfo/onlink
• 'networkr': distinfo/stdorder/digform/digtopt/onlinopt/computer/networka/networkr

ISO:

• 'onlink': gmd:identificationInfo/gmd:MD_DataIdentification/gmd:citation/gmd:CI_Citation/gmd:identifier/gmd:MD_Identifier/gmd:code/gco:CharacterString
• 'networkr': gmd:distributionInfo/gmd:MD_Distribution/gmd:distributor/gmd:MD_Distributor/gmd:distributorTransferOptions/gmd:MD_DigitalTransferOptions/gmd:onLine/gmd:CI_OnlineResource/gmd:linkage/gmd:URL

For 'onlinks', URLs are prioritized according to the following rules:

• USGS DOIs (those containing 10.5066, such as doi.org/10.5066/ and doi.org/doi:10.5066
• non-USGS DOIs (those containing doi.org/, doi.org/doi:, doi:)
• a URL with usgs.gov/

For 'lworkcit', only a USGS DOI will be saved.

For 'networkr', a USGS DOI will be stored if present. Otherwise, any valid URL will be saved.

We are using Pydantic's AnyUrl class to validate URLs.

Error message: The file is missing a DOI.

---

Response

For a file with no validation errors, the API will return a response like the following:

{
  "Success": "The file passed all validation checks."
}

A file with validation errors will have a response body like:

{
  "Errors": [
    "The file is missing a PID.",
    "The PID found in the file is not registered in the PIR database."
  ]
}