Metadata Export

MetadataSerializer exports the study definition as ODM XML — the structural blueprint of the study (visit schedule, CRF forms, field definitions, and code lists) without any subject data.

A receiving system uses this file to understand the shape of the data before importing clinical records.

Usage

from edc_cdisc.serializers import MetadataSerializer

xml_bytes = MetadataSerializer(
    edc_module_name="meta_edc",
    visit_schedule=visit_schedule,
    protocol_oid="S.META",            # optional, defaults to S.<protocol>
    protocol_name="META Trial",       # optional
).to_xml()

Output structure

ODM
  Study  (OID="S.<protocol>")
    GlobalVariables
      StudyName / StudyDescription / ProtocolName
    MetaDataVersion  (OID="MDV.<fingerprint>")
      Protocol
        StudyEventRef ...        (scheduled / unscheduled / common)
      StudyEventDef ...          (one per scheduled visit, unscheduled
                                  collection, and common event)
        FormRef ...
        Alias  (Context="clinicedc.schedule")
      FormDef ...                (one per CRF / requisition / common model)
        ItemGroupRef ...
      ItemGroupDef ...           (one per admin fieldset section)
        ItemRef ...
      ItemDef ...                (one per field)
      CodeList ...               (choice fields)

Study events

Each Visit produces a StudyEventDef:

• Scheduled — OID="SE.<visit_code>", Type="Scheduled". Its FormRef entries are the visit’s CRFs (plus missed-visit and remaining PRN CRFs).

• Unscheduled — OID="UE.<visit_code>", Type="Unscheduled" (built only for visits that define unscheduled CRFs).

• Common — OID="CE.<model>", Type="Common" — the death_report_model and offstudy_model. An abstract / unregistered common model is silently skipped.

Every StudyEventDef carries an <Alias Context="clinicedc.schedule"> naming the schedule it belongs to, so multi-schedule (adaptive) studies keep their grouping even though ODM’s Protocol is a flat list.

Form / item definitions

Fields are read from the registered ModelAdmin’s fieldsets, which provide the authoritative ordering and grouping clinicians see during data entry. Each fieldset section becomes an ItemGroupDef; each field becomes an ItemDef (mapped to an ODM DataType — see ODM Mapping Reference). Choice fields produce CodeList elements.

The MetaDataVersion OID

MetaDataVersion/@OID is MDV.<fingerprint>, where the fingerprint is a SHA-256 over the canonicalized MetaDataVersion subtree. It is therefore stable across releases and changes only when the metadata itself changes. ClinicalDataSerializer computes the same fingerprint, so a data file’s MetaDataVersionOID always matches the metadata edition it conforms to.