# Poco::XML

# class InputSource

Library: XML
Package: SAX
Header: Poco/SAX/InputSource.h

## Description

This class allows a SAX application to encapsulate information about an input source in a single object, which may include a public identifier, a system identifier, a byte stream (possibly with a specified encoding), and/or a character stream.

There are two places that the application can deliver an input source to the parser: as the argument to the Parser.parse method, or as the return value of the EntityResolver::resolveEntity() method.

The SAX parser will use the InputSource object to determine how to read XML input. If there is a character stream available, the parser will read that stream directly, disregarding any text encoding declaration found in that stream. If there is no character stream, but there is a byte stream, the parser will use that byte stream, using the encoding specified in the InputSource or else (if no encoding is specified) autodetecting the character encoding using an algorithm such as the one in the XML specification. If neither a character stream nor a byte stream is available, the parser will attempt to open a URI connection to the resource identified by the system identifier.

An InputSource object belongs to the application: the SAX parser shall never modify it in any way (it may modify a copy if necessary). However, standard processing of both byte and character streams is to close them on as part of end-of-parse cleanup, so applications should not attempt to re-use such streams after they have been handed to a parser.

## Member Summary

Member Functions: getByteStream, getCharacterStream, getEncoding, getPublicId, getSystemId, setByteStream, setCharacterStream, setEncoding, setPublicId, setSystemId

## Constructors

### InputSource

InputSource();

Zero-argument default constructor.

### InputSource

InputSource(
const XMLString & systemId
);

Creates a new input source with a system identifier. Applications may use setPublicId to include a public identifier as well, or setEncoding to specify the character encoding, if known.

If the system identifier is a URL, it must be fully resolved (it may not be a relative URL).

### InputSource

InputSource(
XMLByteInputStream & istr
);

Creates a new input source with a byte stream.

Application writers should use setSystemId() to provide a base for resolving relative URIs, may use setPublicId to include a public identifier, and may use setEncoding to specify the object's character encoding.

## Destructor

### ~InputSource

~InputSource();

Destroys the InputSource.

## Member Functions

### getByteStream

XMLByteInputStream * getByteStream() const;

Get the byte stream for this input source.

### getCharacterStream

XMLCharInputStream * getCharacterStream() const;

Get the character stream for this input source.

### getEncoding

const XMLString & getEncoding() const;

Get the character encoding for a byte stream or URI.

### getPublicId

const XMLString & getPublicId() const;

Get the public identifier for this input source.

### getSystemId

const XMLString & getSystemId() const;

Get the system identifier for this input source.

### setByteStream

void setByteStream(
XMLByteInputStream & istr
);

Set the byte stream for this input source. The SAX parser will ignore this if there is also a character stream specified, but it will use a byte stream in preference to opening a URI connection itself.

### setCharacterStream

void setCharacterStream(
XMLCharInputStream & istr
);

Set the character stream for this input source.

### setEncoding

void setEncoding(
const XMLString & encoding
);

Set the character encoding, if known. The encoding must be a string acceptable for an XML encoding declaration (see section 4.3.3 of the XML 1.0 recommendation).

### setPublicId

void setPublicId(
const XMLString & publicId
);

Set the public identifier for this input source.

The public identifier is always optional: if the application writer includes one, it will be provided as part of the location information.

### setSystemId

void setSystemId(
const XMLString & systemId
);

Set the system identifier for this input source.

The system identifier is optional if there is a byte stream or a character stream, but it is still useful to provide one, since the application can use it to resolve relative URIs and can include it in error messages and warnings (the parser will attempt to open a connection to the URI only if there is no byte stream or character stream specified).

If the application knows the character encoding of the object pointed to by the system identifier, it can register the encoding using the setEncoding method.

If the system identifier is a URL, it must be fully resolved (it may not be a relative URL).