# Method Parser.XML.Validating()->get_external_entity()

Method get_external_entity

  ``string` get_external_entity(`string` `sysid`, `string`|`void` `pubid`, `mapping`|`__deprecated__`(`int`)|`void` `info`, `mixed` ... `extra`)`

Description

  Get an external entity.

  Called when a `<!DOCTYPE>` with a `SYSTEM` identifier is encountered, or when an entity reference needs expanding.

Parameter `sysid`

  The `SYSTEM` identifier.

Parameter `pubid`

  The `PUBLIC` identifier (if any).

Parameter `info`

  The callbackinfo mapping containing the current parser state.

Parameter `extra`

  The `extra` arguments as passed to parse() or parse_dtd().

Returns

  Returns a string with a DTD fragment on success. Returns `0` (zero) on failure.

Note

  Returning zero will cause the validator to report an error.

Note

  In Pike 7.7 and earlier `info` had the value `0` (zero).

Note

  The default implementation always returns `0` (zero). Override this function to provide other behaviour.

See also

  parse(), parse_dtd()