NAME
PICA::Schema - Validate PICA based formats with Avram Schemas
SYNOPSIS
$schema = PICA::Schema->new({ ... });
@errors = $schema->check($record);DESCRIPTION
A PICA Schema defines a set of PICA+ fields and subfields to validate PICA::Data records. Schemas are given as hash reference in Avram Schema language, for instance:
{
  fields => {
    '021A' => { },      # field without additional information
    '003@' => {         # field with additional constraints
      label => 'Pica-Produktionsnummer',
      repeatable => 0,
      required => 1,
      subfields => {
        '0' => { repeatable => 0, required => 1 }
      }
    }
  }
}See PICA::Schema::Builder to automatically construct schemas from PICA sample records.
Schema information can also be used for documentation of records with PICA::Writer::XML.
METHODS
check( $record [, %options ] )
Check whether a given PICA::Data record confirms to the schema and return a list of PICA::Error. Possible options include:
- ignore_unknown_fields
- 
Don't report fields not included in the schema. 
- ignore_unknown_subfields
- 
Don't report subfields not included in the schema. 
- ignore_unknown
- 
Don't report fields and subfields not included in the schema. 
- allow_deprecated_fields
- 
Don't report deprecated fields. 
- allow_deprecated_subfields
- 
Don't report deprecated subfields. 
- allow_deprecated_codes
- 
Don't report deprecated codes. 
- allow_deprecated
- 
Don't report deprecated fields, subfields, and codes. 
- allow_empty_subfields
- 
Don't report subfields with empty string values. 
- ignore_subfield_order
- 
Don't report errors resulting on wrong subfield order. 
- ignore_subfields
- 
Don't check subfields at all. 
- check_annotation
- 
Require or forbid annotated fields if set to true or false. Otherwise just check whether given annotation is a valid character. 
check_field( $field [, %options ] )
Check whether a PICA field confirms to the schema. Use same options as method check. Returns a PICA::Error on schema violation.
abbreviated
Return an abbreviated data structure of the schema without inferable and calculated fields such as tag, occurrence, code, total and records.
FUNCTIONS
clean_pica( $record[, %options] )
Syntactically check a PICA record and return it as array of arrays on success. Syntactic check is performed on schema validation before checking the record against a schema and before writing a record.
Options include:
- error
- 
Error handler, prints instances of PICA::Error to STDERR by default. Use undefto ignore all errors.
- ignore_empty_records
- 
Don't emit an error if the record has no fields. 
- ignore_subfields
- 
Don't check subfields. 
field_identifier( [$schema, ] $field )
Return the field identifier of a given PICA field. The identifier consists of field tag and optional occurrence. If this function is used as method of a schema, the field_identifier may contain an occurrence ranges instead of the plain occurrence.
check_value( $value, $schedule [, %options ] )
Check a subfield value against a subfield schedule. On malformed values returns a subfield error without message key.
check_pattern( $value, $pattern )
Check a value against a pattern and return an error on failure.
LIMITATIONS
Fields types and deprecated (sub)fields in Avram Schemas are not fully supported yet.