json_pointer v0.0.1 → Overview → JSONPointer

JSONPointer

Summary
Types
Functions

Implementation of RFC 6901 which defines a string syntax for identifying a specific value within a JSON document.

Usage

Preleminary note: the actual parsing of the JSON document is outside of the scope of this library, feel free to select on the several libraries available.

The resolve/2 and resolve!/2 functions expect to receive documents in the form of nested maps and lists, as produced by most JSON parsers.

iex> document = %{
...>   "key" => "value",
...>   "list" => [1, 2, 3],
...>   "deeply" => %{"nested" => %{"values" => [%{"x" => 1}, %{"x" => 2}]}}
...> }
iex> JSONPointer.resolve(document, "/key")
{:ok, "value"}
iex> JSONPointer.resolve(document, "/list/1")
{:ok, 2}
iex> JSONPointer.resolve(document, "/deeply/nested/values/0")
{:ok, %{"x" => 1}}
iex> JSONPointer.resolve(document, "/deeply/nested/values/1/x")
{:ok, 2}      
iex> JSONPointer.resolve(document, "/list/4")
{:error, "index 4 out of bounds in [1, 2, 3]"}

Source

Summary↑

escape(string)	Escapes a string in order to be usable as reference token
resolve!(document, expr)	Resolves a JSON Pointer `expr` against the given `document` and returns the referenced value
resolve(document, arg2)	Resolves a JSON Pointer `expr` against the given `document` and returns `{:ok, value}` on success and `{:error, message}` otherwise

Types ↑

json_object :: %{}

Functions

escape(string)

(function) # ↑

Specs:

escape(String.t) :: String.t

Escapes a string in order to be usable as reference token.

iex> JSONPointer.escape("/esc~aped")
"~1esc~0aped"

Source

resolve(document, arg2)

(function) # ↑

Specs:

resolve(json_object, String.t) :: {:ok, json_value} | {:error, String.t}

Resolves a JSON Pointer expr against the given document and returns {:ok, value} on success and {:error, message} otherwise.

iex> JSONPointer.resolve(%{"key" => "value"}, "/key")
{:ok, "value"}
iex> JSONPointer.resolve(%{"key" => "value"}, "/bogus")
{:error, "reference token not found: \"bogus\""}

Source

resolve!(document, expr)

(function) # ↑

Specs:

resolve!(json_object, String.t) :: json_value | no_return

Resolves a JSON Pointer expr against the given document and returns the referenced value.

Raises an ArgumentError exception if an error occurs

iex> JSONPointer.resolve!(%{"key" => "value"}, "/key")
"value"
iex> JSONPointer.resolve!(%{"key" => "value"}, "/bogus")
** (ArgumentError) reference token not found: "bogus"

Source