plJSONReader Class Reference

This JSON reader will read an entire JSON document into a hierarchical structure of plVariants. More...

#include <JSONReader.h>

Inheritance diagram for plJSONReader:

Classes
struct	Element

Public Types
enum class	ElementType : plInt8 { None , Dictionary , Array }

Public Member Functions
plResult	Parse (plStreamReader &ref_input, plUInt32 uiFirstLineOffset=0)
	Reads the entire stream and creates the internal data structure that represents the JSON document. Returns PL_FAILURE if any parsing error occurred.
const plVariantDictionary &	GetTopLevelObject () const
	Returns the top-level object of the JSON document.
const plVariantArray &	GetTopLevelArray () const
	Returns the top-level array of the JSON document.
ElementType	GetTopLevelElementType () const
	Returns whether the top level element is an array or an object.
Public Member Functions inherited from plJSONParser
	plJSONParser ()
	Constructor.
void	SetLogInterface (plLogInterface *pLog)
	Allows to specify an plLogInterface through which errors and warnings are reported.

Protected Attributes
plHybridArray< Element, 32 >	m_Stack
bool	m_bParsingError = false
plString	m_sLastName
Protected Attributes inherited from plJSONParser
plLogInterface *	m_pLogInterface = nullptr

Private Member Functions
virtual bool	OnVariable (plStringView sVarName) override
	This function can be overridden to skip certain variables, however the overriding function must still call this.
virtual void	OnReadValue (plStringView sValue) override
	[internal] Do not override further.
virtual void	OnReadValue (double fValue) override
	[internal] Do not override further.
virtual void	OnReadValue (bool bValue) override
	[internal] Do not override further.
virtual void	OnReadValueNULL () override
	[internal] Do not override further.
virtual void	OnBeginObject () override
	[internal] Do not override further.
virtual void	OnEndObject () override
	[internal] Do not override further.
virtual void	OnBeginArray () override
	[internal] Do not override further.
virtual void	OnEndArray () override
	[internal] Do not override further.
virtual void	OnParsingError (plStringView sMessage, bool bFatal, plUInt32 uiLine, plUInt32 uiColumn) override
	Called when something unexpected is encountered in the JSON document.

Additional Inherited Members
Protected Member Functions inherited from plJSONParser
void	SetInputStream (plStreamReader &stream, plUInt32 uiFirstLineOffset=0)
	Resets the parser to the start state and configures it to read from the given stream.
bool	ContinueParsing ()
	Does one parsing step.
void	ParseAll ()
	Calls ContinueParsing() in a loop until that returns false.
void	SkipObject ()
	Skips the rest of the currently open object. No OnEndArray() and OnEndObject() calls will be done for this object, cleanup must be done manually.
void	SkipArray ()
	Skips the rest of the currently open array. No OnEndArray() and OnEndObject() calls will be done for this object, cleanup must be done manually.
void	ParsingError (plStringView sMessage, bool bFatal)
	Outputs that a parsing error was detected (via OnParsingError) and stops further parsing, if bFatal is set to true.

Detailed Description

This JSON reader will read an entire JSON document into a hierarchical structure of plVariants.

The reader will parse the entire document and create a data structure of plVariants, which can then be traversed easily. Note that this class is much less efficient at reading large JSON documents, as it will dynamically allocate and copy objects around quite a bit. For small to medium sized documents that might be good enough, for large files one should prefer to write a dedicated class derived from plJSONParser.

Member Enumeration Documentation

ElementType

enum class plJSONReader::ElementType : plInt8

strong

Enumerator
None	The JSON document is entirely empty (not even containing an empty object or array)
Dictionary	The top level element in the JSON document is an object.
Array	The top level element in the JSON document is an array.

Member Function Documentation

OnBeginArray()

void plJSONReader::OnBeginArray ( )

overrideprivatevirtual

[internal] Do not override further.

Implements plJSONParser.

OnBeginObject()

void plJSONReader::OnBeginObject ( )

overrideprivatevirtual

[internal] Do not override further.

Implements plJSONParser.

OnEndArray()

void plJSONReader::OnEndArray ( )

overrideprivatevirtual

[internal] Do not override further.

Implements plJSONParser.

OnEndObject()

void plJSONReader::OnEndObject ( )

overrideprivatevirtual

[internal] Do not override further.

Implements plJSONParser.

OnParsingError()

void plJSONReader::OnParsingError ( plStringView sMessage, bool bFatal, plUInt32 uiLine, plUInt32 uiColumn )

overrideprivatevirtual

Called when something unexpected is encountered in the JSON document.

The error message describes what was expected and what was encountered. If bFatal is true, the error has left the parser in an unrecoverable state and thus it not continue parsing. In that case client code will need to clean up it's open state, as no further OnEndObject() / OnEndArray() will be called. If bFatal is false, the document does not contain valid JSON, but the parser is able to continue still.

Reimplemented from plJSONParser.

OnReadValue() [1/3]

void plJSONReader::OnReadValue ( bool bValue )

overrideprivatevirtual

[internal] Do not override further.

Implements plJSONParser.

OnReadValue() [2/3]

void plJSONReader::OnReadValue ( double fValue )

overrideprivatevirtual

[internal] Do not override further.

Implements plJSONParser.

OnReadValue() [3/3]

void plJSONReader::OnReadValue ( plStringView sValue )

overrideprivatevirtual

[internal] Do not override further.

Implements plJSONParser.

OnReadValueNULL()

void plJSONReader::OnReadValueNULL ( )

overrideprivatevirtual

[internal] Do not override further.

Implements plJSONParser.

OnVariable()

bool plJSONReader::OnVariable ( plStringView sVarName )

overrideprivatevirtual

This function can be overridden to skip certain variables, however the overriding function must still call this.

Implements plJSONParser.

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The documentation for this class was generated from the following files:

• Code/Engine/Foundation/IO/JSONReader.h
• Code/Engine/Foundation/IO/Implementation/JSONReader.cpp