Json::StreamWriterBuilder Class Reference

Build a StreamWriter implementation. More...

#include <json/writer.h>

Inherits Json::StreamWriter::Factory.

Public Member Functions
	StreamWriterBuilder ()
	~StreamWriterBuilder () override
StreamWriter *	newStreamWriter () const override
bool	validate (Json::Value *invalid) const
Value &	operator[] (const String &key)
	A simple way to update a specific setting. More...
Public Member Functions inherited from Json::StreamWriter::Factory
virtual	~Factory ()

Static Public Member Functions
static void	setDefaults (Json::Value *settings)
	Called by ctor, but you can use this to reset settings_. More...

Public Attributes
Json::Value	settings_
	Configuration of this builder. More...

Detailed Description

Build a StreamWriter implementation.

Usage:

using namespace Json;
Value value = ...;
StreamWriterBuilder builder;
builder["commentStyle"] = "None";
builder["indentation"] = "   ";  // or whatever you like
std::unique_ptr<Json::StreamWriter> writer(
   builder.newStreamWriter());
writer->write(value, &std::cout);
std::cout << std::endl;  // add lf and flush

Definition at line 89 of file writer.h.

Constructor & Destructor Documentation

StreamWriterBuilder()

Json::StreamWriterBuilder::StreamWriterBuilder

(

)

Definition at line 1156 of file json_writer.cpp.

References setDefaults(), and settings_.

~StreamWriterBuilder()

Json::StreamWriterBuilder::~StreamWriterBuilder ( )

overridedefault

Member Function Documentation

newStreamWriter()

StreamWriter * Json::StreamWriterBuilder::newStreamWriter ( ) const

overridevirtual

Exceptions

std::exception

if something goes wrong (e.g. invalid settings)

Implements Json::StreamWriter::Factory.

Definition at line 1158 of file json_writer.cpp.

References Json::Value::asBool(), Json::Value::asString(), Json::Value::asUInt(), Json::decimalPlaces, settings_, and Json::significantDigits.

Referenced by Json::operator<<().

operator[]()

Value & Json::StreamWriterBuilder::operator[]

(

const String &

key

)

A simple way to update a specific setting.

Definition at line 1228 of file json_writer.cpp.

References settings_.

setDefaults()

void Json::StreamWriterBuilder::setDefaults ( Json::Value *  settings )

static

Called by ctor, but you can use this to reset settings_.

Precondition

'settings' != NULL (but Json::null is fine)

Remarks

Defaults:

  (*settings)["commentStyle"] = "All";
  (*settings)["indentation"] = "\t";
  (*settings)["enableYAMLCompatibility"] = false;
  (*settings)["dropNullPlaceholders"] = false;
  (*settings)["useSpecialFloats"] = false;
  (*settings)["emitUTF8"] = false;
  (*settings)["precision"] = 17;
  (*settings)["precisionType"] = "significant";

[StreamWriterBuilderDefaults]

[StreamWriterBuilderDefaults]

Definition at line 1232 of file json_writer.cpp.

Referenced by StreamWriterBuilder().

validate()

bool Json::StreamWriterBuilder::validate

(

Json::Value *

invalid

)

const

Returns

true if 'settings' are legal and consistent; otherwise, indicate bad settings via 'invalid'.

Definition at line 1211 of file json_writer.cpp.

References Json::Value::empty(), Json::Value::getMemberNames(), Json::getValidWriterKeys(), and settings_.

Member Data Documentation

settings_

Json::Value Json::StreamWriterBuilder::settings_

Configuration of this builder.

Available settings (case-sensitive):

• "commentStyle": "None" or "All"
• "indentation": "<anything>".
• Setting this to an empty string also omits newline characters.
• "enableYAMLCompatibility": false or true
• slightly change the whitespace around colons
• "dropNullPlaceholders": false or true
• Drop the "null" string from the writer's output for nullValues. Strictly speaking, this is not valid JSON. But when the output is being fed to a browser's JavaScript, it makes for smaller output and the browser can handle the output just fine.
• "useSpecialFloats": false or true
• If true, outputs non-finite floating point values in the following way: NaN values as "NaN", positive infinity as "Infinity", and negative infinity as "-Infinity".
• "precision": int
• Number of precision digits for formatting of real values.
• "precisionType": "significant"(default) or "decimal"
• Type of precision for formatting of real values.

You can examine 'settings_` yourself to see the defaults. You can also write and read them just like any JSON Value.

See also

setDefaults()

Definition at line 119 of file writer.h.

Referenced by newStreamWriter(), operator[](), StreamWriterBuilder(), and validate().

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

• include/json/writer.h
• src/lib_json/json_writer.cpp