using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Text; using System.Threading.Tasks; namespace Implab.JSON { public class JSONWriter { struct Context { public bool needComma; public JSONElementContext element; } Stack m_contextStack = new Stack(); Context m_context; TextWriter m_writer; readonly bool m_indent = true; readonly int m_indentSize = 4; static readonly char [] _escapeBKS, _escapeFWD, _escapeCR, _escapeNL, _escapeTAB, _escapeSLASH, _escapeBSLASH, _escapeQ; static JSONWriter() { _escapeBKS = "\\b".ToCharArray(); _escapeFWD = "\\f".ToCharArray(); _escapeCR = "\\r".ToCharArray(); _escapeNL = "\\n".ToCharArray(); _escapeTAB = "\\t".ToCharArray(); _escapeBSLASH = "\\\\".ToCharArray(); _escapeSLASH = "\\/".ToCharArray(); _escapeQ = "\\\"".ToCharArray(); } public JSONWriter(TextWriter writer) { Safe.ArgumentNotNull(writer, "writer"); m_writer = writer; } public JSONWriter(TextWriter writer, bool indent) { Safe.ArgumentNotNull(writer, "writer"); m_writer = writer; m_indent = indent; } void WriteIndent() { if (m_indent) { var indent = new char[m_contextStack.Count * m_indentSize + 1]; indent[0] = '\n'; for (int i = 1; i < indent.Length; i++) indent[i] = ' '; m_writer.Write(new String(indent)); } else { m_writer.Write(' '); } } void WriteMemberName(string name) { Safe.ArgumentNotEmpty(name, "name"); if (m_context.element != JSONElementContext.Object) OperationNotApplicable("WriteMember"); if (m_context.needComma) m_writer.Write(","); WriteIndent(); m_context.needComma = true; Write(name); m_writer.Write(" : "); } public void WriteValue(string name, string value) { WriteMemberName(name); Write(value); } public void WriteValue(string name, bool value) { WriteMemberName(name); Write(value); } public void WriteValue(string name, double value) { WriteMemberName(name); Write(value); } public void WriteValue(string value) { if (m_context.element != JSONElementContext.Array) OperationNotApplicable("WriteValue"); if (m_context.needComma) m_writer.Write(","); WriteIndent(); m_context.needComma = true; Write(value); } public void WriteValue(bool value) { if (m_context.element != JSONElementContext.Array) OperationNotApplicable("WriteValue"); if (m_context.needComma) m_writer.Write(","); m_context.needComma = true; WriteIndent(); Write(value); } public void WriteValue(double value) { if (m_context.element != JSONElementContext.Array) OperationNotApplicable("WriteValue"); if (m_context.needComma) m_writer.Write(","); m_context.needComma = true; WriteIndent(); Write(value); } public void BeginObject() { if (m_context.element != JSONElementContext.None && m_context.element != JSONElementContext.Array) OperationNotApplicable("BeginObject"); if (m_context.needComma) m_writer.Write(","); WriteIndent(); m_context.needComma = true; m_contextStack.Push(m_context); m_context = new Context { element = JSONElementContext.Object, needComma = false }; m_writer.Write("{"); } public void BeginObject(string name) { WriteMemberName(name); m_contextStack.Push(m_context); m_context = new Context { element = JSONElementContext.Object, needComma = false }; m_writer.Write("{"); } public void EndObject() { if (m_context.element != JSONElementContext.Object) OperationNotApplicable("EndArray"); m_context = m_contextStack.Pop(); WriteIndent(); m_writer.Write("}"); } public void BeginArray() { if (m_context.element != JSONElementContext.None && m_context.element != JSONElementContext.Array) throw new InvalidOperationException(); if (m_context.needComma) { m_writer.Write(","); } m_context.needComma = true; WriteIndent(); m_contextStack.Push(m_context); m_context = new Context { element = JSONElementContext.Array, needComma = false }; m_writer.Write("["); } public void BeginArray(string name) { WriteMemberName(name); m_contextStack.Push(m_context); m_context = new Context { element = JSONElementContext.Array, needComma = false }; m_writer.Write("["); } public void EndArray() { if (m_context.element != JSONElementContext.Array) OperationNotApplicable("EndArray"); m_context = m_contextStack.Pop(); WriteIndent(); m_writer.Write("]"); } void Write(bool value) { m_writer.Write(value ? "true" : "false"); } void Write(string value) { if (value == null) { m_writer.Write("null"); return; } var chars = value.ToCharArray(); m_writer.Write('"'); for (int i = 0; i < chars.Length; i++) { var ch = chars[i]; switch (ch) { case '\b': m_writer.Write(_escapeBKS); break; case '\f': m_writer.Write(_escapeFWD); break; case '\r': m_writer.Write(_escapeCR); break; case '\n': m_writer.Write(_escapeNL); break; case '\t': m_writer.Write(_escapeTAB); break; case '\\': m_writer.Write(_escapeBSLASH); break; case '/': m_writer.Write(_escapeSLASH); break; case '"': m_writer.Write(_escapeQ); break; default: if (ch < 0x20) { m_writer.Write("\\u00{0:x2}",(int)ch); } else { m_writer.Write(ch); } break; } } m_writer.Write('"'); } void Write(double value) { m_writer.Write(value); } void OperationNotApplicable(string opName) { throw new InvalidOperationException(String.Format("The operation '{0}' isn't applicable in the context of '{1}'", opName, m_context.element )); } } }