### Struct

# Json Node

since: 1.0

#### Description [src]

    struct JsonNode {
      /* No available fields */
    }

A generic container of JSON data types.

`JsonNode` can contain fundamental types (integers, booleans, floating point numbers, strings) and complex types (arrays and objects).

When parsing a JSON data stream you extract the root node and walk the node tree by retrieving the type of data contained inside the node with the `JSON_NODE_TYPE` macro. If the node contains a fundamental type you can retrieve a copy of the `GValue` holding it with the `json_node_get_value()` function, and then use the `GValue` API to extract the data; if the node contains a complex type you can retrieve the `JsonObject` or the `JsonArray` using `json_node_get_object()` or `json_node_get_array()` respectively, and then retrieve the nodes they contain.

A `JsonNode` may be marked as immutable using `json_node_seal()`. This marks the node and all its descendents as read-only, and means that subsequent calls to setter functions (such as `json_node_set_array()`) on them will abort as a programmer error. By marking a node tree as immutable, it may be referenced in multiple places and its hash value cached for fast lookups, without the possibility of a value deep within the tree changing and affecting hash values. Immutable nodes may be passed to functions which retain a reference to them without needing to take a copy.

A `JsonNode` supports two types of memory management: `malloc`/`free` semantics, and reference counting semantics. The two may be mixed to a limited extent: nodes may be allocated (which gives them a reference count of 1), referenced one or more times, unreferenced exactly that number of times (using `json_node_unref()`), then either unreferenced exactly once more or freed (using `json_node_free()`) to destroy them. The `json_node_free()` function must not be used when a node might have a reference count not equal to 1. To this end, JSON-GLib uses `json_node_copy()` and `json_node_unref()` internally.

Available since: 1.0

#### Constructors

###### json_node_alloc

Allocates a new, uninitialized node.

since: 0.16

###### json_node_new

Creates a new node holding the given `type`.

since: 1.0

#### Instance methods

###### json_node_copy

Copies `node`.

since: 1.0

###### json_node_dup_array

Retrieves the JSON array inside `node`.

since: 1.0

###### json_node_dup_object

Retrieves the object inside `node`.

since: 1.0

###### json_node_dup_string

Gets a copy of the string value stored inside a node.

since: 1.0

###### json_node_equal

Check whether `a` and `b` are equal node, meaning they have the same type and same values (checked recursively).

since: 1.2

###### json_node_free

Frees the resources allocated by the node.

since: 1.0

###### json_node_get_array

Retrieves the JSON array stored inside a node.

since: 1.0

###### json_node_get_boolean

Gets the boolean value stored inside a node.

since: 1.0

###### json_node_get_double

Gets the double value stored inside a node.

since: 1.0

###### json_node_get_int

Gets the integer value stored inside a node.

since: 1.0

###### json_node_get_node_type

Retrieves the type of a `node`.

since: 0.8

###### json_node_get_object

Retrieves the object stored inside a node.

since: 1.0

###### json_node_get_parent

Retrieves the parent node of the given `node`.

since: 1.0

###### json_node_get_string

Gets the string value stored inside a node.

since: 1.0

###### json_node_get_value

Retrieves a value from a node and copies into `value`.

since: 1.0

###### json_node_get_value_type

Returns the `GType` of the payload of the node.

since: 0.4

###### json_node_hash

Calculate a hash value for the given `key`.

since: 1.2

###### json_node_init

Initializes a `node` to a specific `type`.

since: 0.16

###### json_node_init_array

Initializes `node` to `JSON_NODE_ARRAY` and sets `array` into it.

since: 0.16

###### json_node_init_boolean

Initializes `node` to `JSON_NODE_VALUE` and sets `value` into it.

since: 0.16

###### json_node_init_double

Initializes `node` to `JSON_NODE_VALUE` and sets `value` into it.

since: 0.16

###### json_node_init_int

Initializes `node` to `JSON_NODE_VALUE` and sets `value` into it.

since: 0.16

###### json_node_init_null

Initializes `node` to `JSON_NODE_NULL`.

since: 0.16

###### json_node_init_object

Initializes `node` to `JSON_NODE_OBJECT` and sets `object` into it.

since: 0.16

###### json_node_init_string

Initializes `node` to `JSON_NODE_VALUE` and sets `value` into it.

since: 0.16

###### json_node_is_immutable

Check whether the given `node` has been marked as immutable by calling `json_node_seal()` on it.

since: 1.2

###### json_node_is_null

Checks whether `node` is a `JSON_NODE_NULL`.

since: 0.8

###### json_node_ref

Increments the reference count of `node`.

since: 1.2

###### json_node_seal

Seals the given node, making it immutable to further changes.

since: 1.2

###### json_node_set_array

Sets `array` inside `node`.

since: 1.0

###### json_node_set_boolean

Sets `value` as the boolean content of the `node`, replacing any existing content.

since: 1.0

###### json_node_set_double

Sets `value` as the double content of the `node`, replacing any existing content.

since: 1.0

###### json_node_set_int

Sets `value` as the integer content of the `node`, replacing any existing content.

since: 1.0

###### json_node_set_object

Sets `objects` inside `node`.

since: 1.0

###### json_node_set_parent

Sets the parent node for the given `node`.

since: 0.8

###### json_node_set_string

Sets `value` as the string content of the `node`, replacing any existing content.

since: 1.0

###### json_node_set_value

Sets a scalar value inside the given node.

since: 1.0

###### json_node_take_array

Sets `array` inside `node`.

since: 1.0

###### json_node_take_object

Sets `object` inside `node`.

since: 1.0

###### json_node_type_name

Retrieves the user readable name of the data type contained by `node`.

since: 1.0

###### json_node_unref

Decrements the reference count of `node`.

since: 1.2