json2.js

json2.js

// original-ish implementation https://en.wikipedia.org/wiki/Douglas_Crockford
(function() {
  "use strict";

  var rx_one = /^[\],:{}\s]*$/;
  var rx_two = /\\(?:["\\\/bfnrt]|u[0-9a-fA-F]{4})/g;
  var rx_three = /"[^"\\\n\r]*"|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g;
  var rx_four = /(?:^|:|,)(?:\s*\[)+/g;
  var rx_escapable = /[\\"\u0000-\u001f\u007f-\u009f\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g;
  var rx_dangerous = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g;

  function f(n) {
    return (n < 10) ?
      "0" + n :
      n;
  }

  function this_value() {
    return this.valueOf();
  }

  if (typeof Date.prototype.toJSON !== "function") {

    Date.prototype.toJSON = function() {

      return isFinite(this.valueOf()) ?
        (
          this.getUTCFullYear() +
          "-" +
          f(this.getUTCMonth() + 1) +
          "-" +
          f(this.getUTCDate()) +
          "T" +
          f(this.getUTCHours()) +
          ":" +
          f(this.getUTCMinutes()) +
          ":" +
          f(this.getUTCSeconds()) +
          "Z"
        ) :
        null;
    };

    Boolean.prototype.toJSON = this_value;
    Number.prototype.toJSON = this_value;
    String.prototype.toJSON = this_value;
  }

  var gap;
  var indent;
  var meta;
  var rep;

  function quote(string) {

    rx_escapable.lastIndex = 0;
    return rx_escapable.test(string) ?
      "\"" + string.replace(rx_escapable, function(a) {
        var c = meta[a];
        return typeof c === "string" ?
          c :
          "\\u" + ("0000" + a.charCodeAt(0).toString(16)).slice(-4);
      }) + "\"" :
      "\"" + string + "\"";
  }

  function str(key, holder) {

    var i;
    var k;
    var v;
    var length;
    var mind = gap;
    var partial;
    var value = holder[key];

    if (
      value &&
      typeof value === "object" &&
      typeof value.toJSON === "function"
    ) {
      value = value.toJSON(key);
    }

    if (typeof rep === "function") {
      value = rep.call(holder, key, value);
    }

    switch (typeof value) {
      case "string":
        return quote(value);

      case "number":

        return (isFinite(value)) ?
          String(value) :
          "null";

      case "boolean":
      case "null":

        return String(value);

      case "object":

        if (!value) {
          return "null";
        }

        gap += indent;
        partial = [];

        if (Object.prototype.toString.apply(value) === "[object Array]") {

          length = value.length;
          for (i = 0; i < length; i += 1) {
            partial[i] = str(i, value) || "null";
          }

          v = partial.length === 0 ?
            "[]" :
            gap ?
            (
              "[\n" +
              gap +
              partial.join(",\n" + gap) +
              "\n" +
              mind +
              "]"
            ) :
            "[" + partial.join(",") + "]";
          gap = mind;
          return v;
        }

        if (rep && typeof rep === "object") {
          length = rep.length;
          for (i = 0; i < length; i += 1) {
            if (typeof rep[i] === "string") {
              k = rep[i];
              v = str(k, value);
              if (v) {
                partial.push(quote(k) + (
                  (gap) ?
                  ": " :
                  ":"
                ) + v);
              }
            }
          }
        } else {

          for (k in value) {
            if (Object.prototype.hasOwnProperty.call(value, k)) {
              v = str(k, value);
              if (v) {
                partial.push(quote(k) + (
                  (gap) ?
                  ": " :
                  ":"
                ) + v);
              }
            }
          }
        }

        v = partial.length === 0 ?
          "{}" :
          gap ?
          "{\n" + gap + partial.join(",\n" + gap) + "\n" + mind + "}" :
          "{" + partial.join(",") + "}";
        gap = mind;
        return v;
    }
  }

  if (typeof JSON.stringify !== "function") {
    meta = {
      "\b": "\\b",
      "\t": "\\t",
      "\n": "\\n",
      "\f": "\\f",
      "\r": "\\r",
      "\"": "\\\"",
      "\\": "\\\\"
    };
    JSON.stringify = function(value, replacer, space) {

      var i;
      gap = "";
      indent = "";

      if (typeof space === "number") {
        for (i = 0; i < space; i += 1) {
          indent += " ";
        }

      } else if (typeof space === "string") {
        indent = space;
      }

      rep = replacer;
      if (replacer && typeof replacer !== "function" && (
          typeof replacer !== "object" ||
          typeof replacer.length !== "number"
        )) {
        throw new Error("JSON.stringify");
      }

      return str("", {
        "": value
      });
    };
  }

  if (typeof JSON.parse !== "function") {
    JSON.parse = function(text, reviver) {

      var j;

      function walk(holder, key) {

        var k;
        var v;
        var value = holder[key];
        if (value && typeof value === "object") {
          for (k in value) {
            if (Object.prototype.hasOwnProperty.call(value, k)) {
              v = walk(value, k);
              if (v !== undefined) {
                value[k] = v;
              } else {
                delete value[k];
              }
            }
          }
        }
        return reviver.call(holder, key, value);
      }

      text = String(text);
      rx_dangerous.lastIndex = 0;
      if (rx_dangerous.test(text)) {
        text = text.replace(rx_dangerous, function(a) {
          return (
            "\\u" +
            ("0000" + a.charCodeAt(0).toString(16)).slice(-4)
          );
        });
      }

      if (
        rx_one.test(
          text
          .replace(rx_two, "@")
          .replace(rx_three, "]")
          .replace(rx_four, "")
        )
      ) {

        j = eval("(" + text + ")");

        return (typeof reviver === "function") ?
          walk({
            "": j
          }, "") :
          j;
      }

      throw new SyntaxError("JSON.parse");
    };
  }
}());