Added StyledStreamWriter, which has no reason to derive from Writer, since its write() method does cannot return a string and must take a stream.

This commit is contained in:
Christopher Dunn 2007-06-13 15:55:50 +00:00
parent 8985cee674
commit 605cd7e902
2 changed files with 344 additions and 4 deletions

View File

@ -30,6 +30,7 @@ namespace Json {
{
public:
FastWriter();
virtual ~FastWriter(){}
void enableYAMLCompatibility();
@ -61,7 +62,7 @@ namespace Json {
*
* \sa Reader, Value, Value::setComment()
*/
class JSON_API StyledWriter
class JSON_API StyledWriter: public Writer
{
public:
StyledWriter();
@ -98,13 +99,71 @@ namespace Json {
bool addChildValues_;
};
/** \brief Writes a Value in <a HREF="http://www.json.org">JSON</a> format in a human friendly way,
to a stream rather than to a string.
*
* The rules for line break and indent are as follow:
* - Object value:
* - if empty then print {} without indent and line break
* - if not empty the print '{', line break & indent, print one value per line
* and then unindent and line break and print '}'.
* - Array value:
* - if empty then print [] without indent and line break
* - if the array contains no object value, empty array or some other value types,
* and all the values fit on one lines, then print the array on a single line.
* - otherwise, it the values do not fit on one line, or the array contains
* object or non empty array, then print one value per line.
*
* If the Value have comments then they are outputed according to their #CommentPlacement.
*
* \param indentation Each level will be indented by this amount extra.
* \sa Reader, Value, Value::setComment()
*/
class JSON_API StyledStreamWriter
{
public:
StyledStreamWriter( std::string indentation="\t" );
~StyledStreamWriter(){}
public:
/** \brief Serialize a Value in <a HREF="http://www.json.org">JSON</a> format.
* \param out Stream to write to. (Can be ostringstream, e.g.)
* \param root Value to serialize.
* \note There is no point in deriving from Writer, since write() should not return a value.
*/
void write( std::ostream &out, const Value &root );
private:
void writeValue( const Value &value );
void writeArrayValue( const Value &value );
bool isMultineArray( const Value &value );
void pushValue( const std::string &value );
void writeIndent();
void writeWithIndent( const std::string &value );
void indent();
void unindent();
void writeCommentBeforeValue( const Value &root );
void writeCommentAfterValueOnSameLine( const Value &root );
bool hasCommentForValue( const Value &value );
static std::string normalizeEOL( const std::string &text );
typedef std::vector<std::string> ChildValues;
ChildValues childValues_;
std::ostream* document_;
std::string indentString_;
int rightMargin_;
std::string indentation_;
bool addChildValues_;
};
std::string JSON_API valueToString( Value::Int value );
std::string JSON_API valueToString( Value::UInt value );
std::string JSON_API valueToString( double value );
std::string JSON_API valueToString( bool value );
std::string JSON_API valueToQuotedString( const char *value );
/// \brief Output using the StyledWriter.
/// \brief Output using the StyledStreamWriter.
/// \see Json::operator>>()
std::ostream& operator<<( std::ostream&, const Value &root );

View File

@ -476,10 +476,291 @@ StyledWriter::normalizeEOL( const std::string &text )
return normalized;
}
// Class StyledStreamWriter
// //////////////////////////////////////////////////////////////////
StyledStreamWriter::StyledStreamWriter( std::string indentation )
: document_(NULL)
, rightMargin_( 74 )
, indentation_( indentation )
{
}
void
StyledStreamWriter::write( std::ostream &out, const Value &root )
{
document_ = &out;
addChildValues_ = false;
indentString_ = "";
writeCommentBeforeValue( root );
writeValue( root );
writeCommentAfterValueOnSameLine( root );
*document_ << "\n";
document_ = NULL; // Forget the stream, for safety.
}
void
StyledStreamWriter::writeValue( const Value &value )
{
switch ( value.type() )
{
case nullValue:
pushValue( "null" );
break;
case intValue:
pushValue( valueToString( value.asInt() ) );
break;
case uintValue:
pushValue( valueToString( value.asUInt() ) );
break;
case realValue:
pushValue( valueToString( value.asDouble() ) );
break;
case stringValue:
pushValue( valueToQuotedString( value.asCString() ) );
break;
case booleanValue:
pushValue( valueToString( value.asBool() ) );
break;
case arrayValue:
writeArrayValue( value);
break;
case objectValue:
{
Value::Members members( value.getMemberNames() );
if ( members.empty() )
pushValue( "{}" );
else
{
writeWithIndent( "{" );
indent();
Value::Members::iterator it = members.begin();
while ( true )
{
const std::string &name = *it;
const Value &childValue = value[name];
writeCommentBeforeValue( childValue );
writeWithIndent( valueToQuotedString( name.c_str() ) );
*document_ << " : ";
writeValue( childValue );
if ( ++it == members.end() )
{
writeCommentAfterValueOnSameLine( childValue );
break;
}
*document_ << ",";
writeCommentAfterValueOnSameLine( childValue );
}
unindent();
writeWithIndent( "}" );
}
}
break;
}
}
void
StyledStreamWriter::writeArrayValue( const Value &value )
{
unsigned size = value.size();
if ( size == 0 )
pushValue( "[]" );
else
{
bool isArrayMultiLine = isMultineArray( value );
if ( isArrayMultiLine )
{
writeWithIndent( "[" );
indent();
bool hasChildValue = !childValues_.empty();
unsigned index =0;
while ( true )
{
const Value &childValue = value[index];
writeCommentBeforeValue( childValue );
if ( hasChildValue )
writeWithIndent( childValues_[index] );
else
{
writeIndent();
writeValue( childValue );
}
if ( ++index == size )
{
writeCommentAfterValueOnSameLine( childValue );
break;
}
*document_ << ",";
writeCommentAfterValueOnSameLine( childValue );
}
unindent();
writeWithIndent( "]" );
}
else // output on a single line
{
assert( childValues_.size() == size );
*document_ << "[ ";
for ( unsigned index =0; index < size; ++index )
{
if ( index > 0 )
*document_ << ", ";
*document_ << childValues_[index];
}
*document_ << " ]";
}
}
}
bool
StyledStreamWriter::isMultineArray( const Value &value )
{
int size = value.size();
bool isMultiLine = size*3 >= rightMargin_ ;
childValues_.clear();
for ( int index =0; index < size && !isMultiLine; ++index )
{
const Value &childValue = value[index];
isMultiLine = isMultiLine ||
( (childValue.isArray() || childValue.isObject()) &&
childValue.size() > 0 );
}
if ( !isMultiLine ) // check if line length > max line length
{
childValues_.reserve( size );
addChildValues_ = true;
int lineLength = 4 + (size-1)*2; // '[ ' + ', '*n + ' ]'
for ( int index =0; index < size && !isMultiLine; ++index )
{
writeValue( value[index] );
lineLength += int( childValues_[index].length() );
isMultiLine = isMultiLine && hasCommentForValue( value[index] );
}
addChildValues_ = false;
isMultiLine = isMultiLine || lineLength >= rightMargin_;
}
return isMultiLine;
}
void
StyledStreamWriter::pushValue( const std::string &value )
{
if ( addChildValues_ )
childValues_.push_back( value );
else
*document_ << value;
}
void
StyledStreamWriter::writeIndent()
{
/*
Some comments in this method would have been nice. ;-)
if ( !document_.empty() )
{
char last = document_[document_.length()-1];
if ( last == ' ' ) // already indented
return;
if ( last != '\n' ) // Comments may add new-line
*document_ << '\n';
}
*/
*document_ << indentString_;
}
void
StyledStreamWriter::writeWithIndent( const std::string &value )
{
writeIndent();
*document_ << value;
}
void
StyledStreamWriter::indent()
{
indentString_ += indentation_;
}
void
StyledStreamWriter::unindent()
{
assert( indentString_.size() >= indentation_.size() );
indentString_.resize( indentString_.size() - indentation_.size() );
}
void
StyledStreamWriter::writeCommentBeforeValue( const Value &root )
{
if ( !root.hasComment( commentBefore ) )
return;
*document_ << normalizeEOL( root.getComment( commentBefore ) );
*document_ << "\n";
}
void
StyledStreamWriter::writeCommentAfterValueOnSameLine( const Value &root )
{
if ( root.hasComment( commentAfterOnSameLine ) )
*document_ << " " + normalizeEOL( root.getComment( commentAfterOnSameLine ) );
if ( root.hasComment( commentAfter ) )
{
*document_ << "\n";
*document_ << normalizeEOL( root.getComment( commentAfter ) );
*document_ << "\n";
}
}
bool
StyledStreamWriter::hasCommentForValue( const Value &value )
{
return value.hasComment( commentBefore )
|| value.hasComment( commentAfterOnSameLine )
|| value.hasComment( commentAfter );
}
std::string
StyledStreamWriter::normalizeEOL( const std::string &text )
{
std::string normalized;
normalized.reserve( text.length() );
const char *begin = text.c_str();
const char *end = begin + text.length();
const char *current = begin;
while ( current != end )
{
char c = *current++;
if ( c == '\r' ) // mac or dos EOL
{
if ( *current == '\n' ) // convert dos EOL
++current;
normalized += '\n';
}
else // handle unix EOL & other char
normalized += c;
}
return normalized;
}
std::ostream& operator<<( std::ostream &sout, const Value &root )
{
Json::StyledWriter writer;
sout << writer.write(root);
Json::StyledStreamWriter writer;
writer.write(sout, root);
return sout;
}