Jason.Formatter (jason v1.3.0) View Source

Pretty-printing and minimizing functions for JSON-encoded data.

Input is required to be in an 8-bit-wide encoding such as UTF-8 or Latin-1 in iodata/0 format. Input must have valid JSON, invalid JSON may produce unexpected results or errors.

Link to this section Summary

Functions

minimize(input, opts \\ [])

Minimizes JSON-encoded input.

minimize_to_iodata(input, opts)

Minimizes JSON-encoded input and returns iodata.

pretty_print(input, opts \\ [])

Pretty-prints JSON-encoded input.

pretty_print_to_iodata(input, opts \\ [])

Pretty-prints JSON-encoded input and returns iodata.

Link to this section Types

opts()

Specs

opts() :: [
  indent: iodata(),
  line_separator: iodata(),
  record_separator: iodata(),
  after_colon: iodata()
]

Link to this section Functions

minimize(input, opts \\ [])

Specs

minimize(iodata(), opts()) :: binary()

Minimizes JSON-encoded input.

input may contain multiple JSON objects or arrays, optionally separated by whitespace (e.g., one object per line). Minimized output will contain one object per line. No trailing newline is emitted.

Options

:record_separator - controls the string used as newline (default: "\n").

Examples

iex> Jason.Formatter.minimize(~s|{ "a" : "b" , "c": \n\n 2}|)
~s|{"a":"b","c":2}|

minimize_to_iodata(input, opts)

Specs

minimize_to_iodata(iodata(), opts()) :: iodata()

Minimizes JSON-encoded input and returns iodata.

This function should be preferred to minimize/2, if the minimized JSON will be handed over to one of the IO functions or sent over the socket. The Erlang runtime is able to leverage vectorised writes and avoid allocating a continuous buffer for the whole resulting string, lowering memory use and increasing performance.

pretty_print(input, opts \\ [])

Specs

pretty_print(iodata(), opts()) :: binary()

Pretty-prints JSON-encoded input.

input may contain multiple JSON objects or arrays, optionally separated by whitespace (e.g., one object per line). Objects in output will be separated by newlines. No trailing newline is emitted.

Options

:indent - used for nested objects and arrays (default: two spaces - " ");
:line_separator - used in nested objects (default: "\n");
:record_separator - separates root-level objects and arrays (default is the value for :line_separator option);
:after_colon - printed after a colon inside objects (default: one space - " ").

Examples

iex> Jason.Formatter.pretty_print(~s|{"a":{"b": [1, 2]}}|)
~s|{
  "a": {
    "b": [
      1,
      2
    ]
  }
}|

pretty_print_to_iodata(input, opts \\ [])

Specs

pretty_print_to_iodata(iodata(), opts()) :: iodata()

Pretty-prints JSON-encoded input and returns iodata.

This function should be preferred to pretty_print/2, if the pretty-printed JSON will be handed over to one of the IO functions or sent over the socket. The Erlang runtime is able to leverage vectorised writes and avoid allocating a continuous buffer for the whole resulting string, lowering memory use and increasing performance.