class JSON::Builder
Overview
A JSON builder generates valid JSON.
A JSON::Error is raised if attempting to generate an invalid JSON (for example, if invoking #end_array without a matching #start_array, or trying to use a non-string value as an object's field name).
Defined in:
json/builder.crConstructors
- .new(io : IO)
Creates a
JSON::Builderthat will write to the givenIO.
Instance Method Summary
- #array(&)
Writes the start of an array, invokes the block, and the writes the end of it.
- #bool(value : Bool) : Nil
Writes a boolean value.
- #document(&)
- #end_array : Nil
Writes the end of an array.
- #end_document : Nil
Signals the end of a JSON document.
- #end_object : Nil
Writes the end of an object.
- #field(name, value)
Writes an object's field and value.
- #field(name, &)
Writes an object's field and then invokes the block.
- #flush
Flushes the underlying
IO. - #indent=(string : String)
Sets the indent string.
- #indent=(level : Int)
Sets the indent level (number of spaces).
- #max_nesting : Int32
By default the maximum nesting of arrays/objects is 99.
- #max_nesting=(max_nesting)
By default the maximum nesting of arrays/objects is 99.
- #next_is_object_key? : Bool
Returns
trueif the next thing that must pushed into this builder is an object key (so a string) or the end of an object. - #null : Nil
Writes a
#nullvalue. - #number(number : Int) : Nil
Writes an integer.
- #number(number : Float) : Nil
Writes a float.
- #object(&)
Writes the start of an object, invokes the block, and the writes the end of it.
- #raw(string : String) : Nil
Writes a raw value, considered a scalar, directly into the IO without processing.
- #scalar(value : Nil)
Writes a scalar value.
- #scalar(value : Bool)
Writes a scalar value.
- #scalar(value : Int | Float) : Nil
Writes a scalar value.
- #scalar(value : String) : Nil
Writes a scalar value.
- #start_array : Nil
Writes the start of an array.
- #start_document : Nil
Starts a document.
- #start_object : Nil
Writes the start of an object.
- #string(value) : Nil
Writes a string.
Instance methods inherited from class Reference
==(other : self)==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference) : Bool
same?(other : Nil) same?, to_s(io : IO) : Nil to_s
Constructor methods inherited from class Reference
new new Instance methods inherited from class Object
! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)===(other : YAML::Any)
===(other) ===, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash hash, in?(collection : Object) : Bool
in?(*values : Object) : Bool in?, inspect(io : IO) : Nil
inspect : String inspect, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) tap, to_json(io : IO) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String to_yaml, try(&) try, unsafe_as(type : T.class) forall T unsafe_as
Class methods inherited from class Object
from_json(string_or_io, root : String)from_json(string_or_io) from_json, from_yaml(string_or_io : String | IO) from_yaml
Constructor Detail
def self.new(io : IO)Source
Creates a JSON::Builder that will write to the given IO.
Instance Method Detail
def array(&)Source
Writes the start of an array, invokes the block, and the writes the end of it.
def document(&)Source
def field(name, value)Source
Writes an object's field and value. The field's name is first converted to a String by invoking to_s on it.
def field(name, &)Source
Writes an object's field and then invokes the block. This is equivalent of invoking #string(value) and then invoking the block.
def max_nesting : Int32Source
By default the maximum nesting of arrays/objects is 99. Nesting more than this will result in a JSON::Error. Changing the value of this property allows more/less nesting.
def max_nesting=(max_nesting)Source
By default the maximum nesting of arrays/objects is 99. Nesting more than this will result in a JSON::Error. Changing the value of this property allows more/less nesting.
def next_is_object_key? : BoolSource
Returns true if the next thing that must pushed into this builder is an object key (so a string) or the end of an object.
def object(&)Source
Writes the start of an object, invokes the block, and the writes the end of it.
def raw(string : String) : NilSource
Writes a raw value, considered a scalar, directly into the IO without processing. This is the only method that might lead to invalid JSON being generated, so you must be sure that string contains a valid JSON string.
def string(value) : NilSource
Writes a string. The given value is first converted to a String by invoking to_s on it.
This method can also be used to write the name of an object field.
© 2012–2021 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/1.2.1/JSON/Builder.html