D Programming Language
Report a bug If you spot a problem with this page, click here to create a Bugzilla issue. Improve this page Quickly fork, edit online, and submit a pull request for this page. Requires a signed-in GitHub account. This works well for small changes. If you'd like to make larger changes you may want to consider using local clone.

# std.json

JavaScript Object Notation

Synopsis:

        //parse a file or string of json into a usable structure
        string s = "{ \"language\": \"D\", \"rating\": 3.14, \"code\": \"42\" }";
        JSONValue j = parseJSON(s);
        writeln("Language: ", j["language"].str(),
                " Rating: ", j["rating"].floating()
        );

        // j and j["language"] return JSONValue,
        // j["language"].str returns a string

        //check a type
        long x;
        if (j["code"].type() == JSON_TYPE.INTEGER)
        {
            x = j["code"].integer;
        }
        else
        {
            x = to!int(j["code"].str);
        }

        // create a json struct
        JSONValue jj = [ "language": "D" ];
        // rating doesnt exist yet, so use .object to assign
        jj.object["rating"] = JSONValue(3.14);
        // create an array to assign to list
        jj.object["list"] = JSONValue( ["a", "b", "c"] );
        // list already exists, so .object optional
        jj["list"].array ~= JSONValue("D");

        s = j.toString();
        writeln(s);

License:
Boost License 1.0.
Authors:
Jeremie Pelletier, David Herberth

References: http://json.org/

Source: std/json.d

enum JSONFloatLiteral: string;
  String literals used to represent special float values within JSON strings.
  nan
    string representation of floating-point NaN
  inf
    string representation of floating-point Infinity
  negativeInf
    string representation of floating-point negative Infinity
enum JSONOptions: int;
  Flags that control how json is encoded and parsed.
  none
    standard parsing
  specialFloatLiterals
    encode NaN and Inf float values as strings
enum JSON_TYPE: byte;
  JSON type enumeration
  NULL
  STRING
  INTEGER
  UINTEGER
  FLOAT
  OBJECT
  ARRAY
  TRUE
  FALSE
    Indicates the type of a JSONValue.
struct JSONValue;
  JSON value node
  const pure nothrow @nogc @property @safe JSON_TYPE type();
    Returns the JSON_TYPE of the value stored in this structure.
    Examples:

        string s = "{ \"language\": \"D\" }";
        JSONValue j = parseJSON(s);
        assert(j.type == JSON_TYPE.OBJECT);
        assert(j["language"].type == JSON_TYPE.STRING);

  deprecated @property JSON_TYPE type(JSON_TYPE newType);
    Deprecated. Instead, please assign the value with the adequate type to JSONValue directly. This will be removed in June 2015.
    Sets the type of this JSONValue. Previous content is cleared.
  inout pure @property inout(string) str();
  pure nothrow @nogc @property string str(string v);
    Value getter/setter for JSON_TYPE.STRING.
    Throws JSONException for read access if type is not JSON_TYPE.STRING.
    Examples:

        JSONValue j = [ "language": "D" ];

        // get value
        assert(j["language"].str == "D");

        // change existing key to new string
        j["language"].str = "Perl";
        assert(j["language"].str == "Perl");

  inout pure @property @safe inout(long) integer();
  pure nothrow @nogc @property @safe long integer(long v);
    Value getter/setter for JSON_TYPE.INTEGER.
    Throws JSONException for read access if type is not JSON_TYPE.INTEGER.
  inout pure @property @safe inout(ulong) uinteger();
  pure nothrow @nogc @property @safe ulong uinteger(ulong v);
    Value getter/setter for JSON_TYPE.UINTEGER.
    Throws JSONException for read access if type is not JSON_TYPE.UINTEGER.
  inout pure @property @safe inout(double) floating();
  pure nothrow @nogc @property @safe double floating(double v);
    Value getter/setter for JSON_TYPE.FLOAT.
    Throws JSONException for read access if type is not JSON_TYPE.FLOAT.
  inout pure @property ref inout(JSONValue[string]) object();
  pure nothrow @nogc @property JSONValue[string] object(JSONValue[string] v);
    Value getter/setter for JSON_TYPE.OBJECT.
    Throws JSONException for read access if type is not JSON_TYPE.OBJECT.
  inout pure @property ref inout(JSONValue[]) array();
  pure nothrow @nogc @property JSONValue[] array(JSONValue[] v);
    Value getter/setter for JSON_TYPE.ARRAY.
    Throws JSONException for read access if type is not JSON_TYPE.ARRAY.
  const pure nothrow @nogc @property @safe bool isNull();
    Test whether the type is JSON_TYPE.NULL
  this(T)(T arg) if (!isStaticArray!T);
  this(T)(ref T arg) if (isStaticArray!T);
  inout this(T : JSONValue)(inout T arg);
    Constructor for JSONValue. If arg is a JSONValue its value and type will be copied to the new JSONValue. Note that this is a shallow copy: if type is JSON_TYPE.OBJECT or JSON_TYPE.ARRAY then only the reference to the data will be copied. Otherwise, arg must be implicitly convertible to one of the following types: typeof(null), string, ulong, long, double, an associative array V[K] for any V and K i.e. a JSON object, any array or bool. The type will be set accordingly.
    Examples:

        JSONValue j = JSONValue( "a string" );
        j = JSONValue(42);

        j = JSONValue( [1, 2, 3] );
        assert(j.type == JSON_TYPE.ARRAY);

        j = JSONValue( ["language": "D"] );
        assert(j.type == JSON_TYPE.OBJECT);

  inout pure ref inout(JSONValue) opIndex(size_t i);
    Array syntax for json arrays.
    Throws JSONException if type is not JSON_TYPE.ARRAY.
    Examples:

        JSONValue j = JSONValue( [42, 43, 44] );
        assert( j[0].integer == 42 );
        assert( j[1].integer == 43 );

  inout pure ref inout(JSONValue) opIndex(string k);
    Hash syntax for json objects.
    Throws JSONException if type is not JSON_TYPE.OBJECT.
    Examples:

        JSONValue j = JSONValue( ["language": "D"] );
        assert( j["language"].str == "D" );

  pure void opIndexAssign(T)(auto ref T value, string key);
    Operator sets value for element of JSON object by key
    If JSON value is null, then operator initializes it with object and then

    sets value for it.

    Throws JSONException if type is not JSON_TYPE.OBJECT

    or JSON_TYPE.NULL.
    Examples:

        JSONValue j = JSONValue( ["language": "D"] );
        j["language"].str = "Perl";
        assert( j["language"].str == "Perl" );

  int opApply(int delegate(size_t index, ref JSONValue) dg);
    Implements the foreach opApply interface for json arrays.
  int opApply(int delegate(string key, ref JSONValue) dg);
    Implements the foreach opApply interface for json objects.
  const string toString(in JSONOptions options = JSONOptions.none);
    Implicitly calls toJSON on this JSONValue.
    options can be used to tweak the conversion behavior.
  const string toPrettyString(in JSONOptions options = JSONOptions.none);
    Implicitly calls toJSON on this JSONValue, like toString, but
    also passes true as pretty argument.

    options can be used to tweak the conversion behavior
JSONValue parseJSON(T)(T json, int maxDepth = -1, JSONOptions options = JSONOptions.none) if (isInputRange!T);
  Parses a serialized string and returns a tree of JSON values. Throws a std.json.JSONException if the depth exceeds the max depth.
  Parameters:

  T json | json-formatted string to parse
  int maxDepth | maximum depth of nesting allowed, -1 disables depth checking
  JSONOptions options | enable decoding string representations of NaN/Inf as float values

JSONValue parseJSON(T)(T json, JSONOptions options) if (isInputRange!T);
  Parses a serialized string and returns a tree of JSON values. Throws a std.json.JSONException if the depth exceeds the max depth.
  Parameters:

  T json | json-formatted string to parse
  JSONOptions options | enable decoding string representations of NaN/Inf as float values

string toJSON(in JSONValue* root, in bool pretty = false, in JSONOptions options = JSONOptions.none);
  Takes a tree of JSON values and returns the serialized string.
  Any Object types will be serialized in a key-sorted order.

  If pretty is false no whitespaces are generated. If pretty is true serialized string is formatted to be human-readable. Set the flag is set in options to encode NaN/Infinity as strings.
class JSONException: object.Exception;
  Exception thrown on JSON errors

Copyright Jeremie Pelletier 2008 - 2009. | Page generated by Ddoc on Thu Dec 3 01:39:46 2015