godot/doc/classes/JSON.xml
Rémi Verschelde 81064cc239
Doctool: Remove version attribute from XML header
We don't use that info for anything, and it generates unnecessary diffs
every time we bump the minor version (and CI failures if we forget to
sync some files from opt-in modules (mono, text_server_fb).
2023-07-06 10:08:21 +02:00

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XML

<?xml version="1.0" encoding="UTF-8" ?>
<class name="JSON" inherits="Resource" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
<brief_description>
Helper class for creating and parsing JSON data.
</brief_description>
<description>
The [JSON] enables all data types to be converted to and from a JSON string. This useful for serializing data to save to a file or send over the network.
[method stringify] is used to convert any data type into a JSON string.
[method parse] is used to convert any existing JSON data into a [Variant] that can be used within Godot. If successfully parsed, use [member data] to retrieve the [Variant], and use [code]typeof[/code] to check if the Variant's type is what you expect. JSON Objects are converted into a [Dictionary], but JSON data can be used to store [Array]s, numbers, [String]s and even just a boolean.
[b]Example[/b]
[codeblock]
var data_to_send = ["a", "b", "c"]
var json_string = JSON.stringify(data_to_send)
# Save data
# ...
# Retrieve data
var json = JSON.new()
var error = json.parse(json_string)
if error == OK:
var data_received = json.data
if typeof(data_received) == TYPE_ARRAY:
print(data_received) # Prints array
else:
print("Unexpected data")
else:
print("JSON Parse Error: ", json.get_error_message(), " in ", json_string, " at line ", json.get_error_line())
[/codeblock]
Alternatively, you can parse string using the static [method parse_string] method, but it doesn't allow to handle errors.
[codeblock]
var data = JSON.parse_string(json_string) # Returns null if parsing failed.
[/codeblock]
[b]Note:[/b] Both parse methods do not fully comply with the JSON specification:
- Trailing commas in arrays or objects are ignored, instead of causing a parser error.
- New line and tab characters are accepted in string literals, and are treated like their corresponding escape sequences [code]\n[/code] and [code]\t[/code].
- Numbers are parsed using [method String.to_float] which is generally more lax than the JSON specification.
- Certain errors, such as invalid Unicode sequences, do not cause a parser error. Instead, the string is cleansed and an error is logged to the console.
</description>
<tutorials>
</tutorials>
<methods>
<method name="get_error_line" qualifiers="const">
<return type="int" />
<description>
Returns [code]0[/code] if the last call to [method parse] was successful, or the line number where the parse failed.
</description>
</method>
<method name="get_error_message" qualifiers="const">
<return type="String" />
<description>
Returns an empty string if the last call to [method parse] was successful, or the error message if it failed.
</description>
</method>
<method name="get_parsed_text" qualifiers="const">
<return type="String" />
<description>
Return the text parsed by [method parse] as long as the function is instructed to keep it.
</description>
</method>
<method name="parse">
<return type="int" enum="Error" />
<param index="0" name="json_text" type="String" />
<param index="1" name="keep_text" type="bool" default="false" />
<description>
Attempts to parse the [param json_text] provided.
Returns an [enum Error]. If the parse was successful, it returns [constant OK] and the result can be retrieved using [member data]. If unsuccessful, use [method get_error_line] and [method get_error_message] for identifying the source of the failure.
Non-static variant of [method parse_string], if you want custom error handling.
The optional [param keep_text] argument instructs the parser to keep a copy of the original text. This text can be obtained later by using the [method get_parsed_text] function and is used when saving the resource (instead of generating new text from [member data]).
</description>
</method>
<method name="parse_string" qualifiers="static">
<return type="Variant" />
<param index="0" name="json_string" type="String" />
<description>
Attempts to parse the [param json_string] provided and returns the parsed data. Returns [code]null[/code] if parse failed.
</description>
</method>
<method name="stringify" qualifiers="static">
<return type="String" />
<param index="0" name="data" type="Variant" />
<param index="1" name="indent" type="String" default="&quot;&quot;" />
<param index="2" name="sort_keys" type="bool" default="true" />
<param index="3" name="full_precision" type="bool" default="false" />
<description>
Converts a [Variant] var to JSON text and returns the result. Useful for serializing data to store or send over the network.
[b]Note:[/b] The JSON specification does not define integer or float types, but only a [i]number[/i] type. Therefore, converting a Variant to JSON text will convert all numerical values to [float] types.
[b]Note:[/b] If [param full_precision] is [code]true[/code], when stringifying floats, the unreliable digits are stringified in addition to the reliable digits to guarantee exact decoding.
The [param indent] parameter controls if and how something is indented, the string used for this parameter will be used where there should be an indent in the output, even spaces like [code]" "[/code] will work. [code]\t[/code] and [code]\n[/code] can also be used for a tab indent, or to make a newline for each indent respectively.
[b]Example output:[/b]
[codeblock]
## JSON.stringify(my_dictionary)
{"name":"my_dictionary","version":"1.0.0","entities":[{"name":"entity_0","value":"value_0"},{"name":"entity_1","value":"value_1"}]}
## JSON.stringify(my_dictionary, "\t")
{
"name": "my_dictionary",
"version": "1.0.0",
"entities": [
{
"name": "entity_0",
"value": "value_0"
},
{
"name": "entity_1",
"value": "value_1"
}
]
}
## JSON.stringify(my_dictionary, "...")
{
..."name": "my_dictionary",
..."version": "1.0.0",
..."entities": [
......{
........."name": "entity_0",
........."value": "value_0"
......},
......{
........."name": "entity_1",
........."value": "value_1"
......}
...]
}
[/codeblock]
</description>
</method>
</methods>
<members>
<member name="data" type="Variant" setter="set_data" getter="get_data" default="null">
Contains the parsed JSON data in [Variant] form.
</member>
</members>
</class>