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::Builder
that 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 : Int32)
By default the maximum nesting of arrays/objects is 99.
-
#next_is_object_key? : Bool
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. -
#null : Nil
Writes a
#null
value. -
#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 with the content of
value
. -
#string(& : IO -> ) : Nil
Writes a string with the contents written to the yielded
IO
.
Instance methods inherited from class Reference
==(other : self)==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, initialize initialize, 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,
unsafe_construct(address : Pointer, *args, **opts) : self
unsafe_construct
Class methods inherited from class Reference
pre_initialize(address : Pointer)
pre_initialize
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!(message)
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
Instance Method Detail
Writes an object's field and value.
The field's name is first converted to a String
by invoking
to_s
on it.
Writes an object's field and then invokes the block.
This is equivalent of invoking #string(value)
and then
invoking the block.
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.
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.
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.
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.
Writes a string with the content of value
.
The payload is stringified via to_s(IO)
and escaped for JSON representation.
JSON.build do |builder|
builder.string("foo")
end # => %("foo")
JSON.build do |builder|
builder.string([1, 2])
end # => %("[1, 2]")
This method can also be used to write the name of an object field.
Writes a string with the contents written to the yielded IO
.
The payload gets escaped for JSON representation.
JSON.build do |builder|
builder.string do |io|
io << "foo"
io << [1, 2]
end # => %("foo[1, 2]")
end
This method can also be used to write the name of an object field.