View Source JSONPathEx (JSONPathEx v0.1.0)

Main interface for the JSONPathEx library.

JSONPathEx provides tools to parse and evaluate JSONPath expressions against JSON data. This module serves as the main entry point, combining parsing and evaluation into a single, convenient function.

Features

  • Parse JSONPath expressions into Abstract Syntax Trees (ASTs).
  • Evaluate JSONPath expressions or ASTs against JSON data.
  • Supports filters, recursive descent, array slicing, and built-in functions.

Examples 

iex> json_data = %{
...>   "store" => %{
...>     "book" => [
...>       %{
...>         "category" => "reference",
...>         "author" => "Nigel Rees",
...>         "title" => "Sayings of the Century",
...>         "price" => 8.95
...>       }
...>     ]
...>   }
...> }
iex> JSONPathEx.evaluate("$.store.book[*].title", json_data)
{:ok, ["Sayings of the Century"]}

Summary

Functions

evaluate(expression, json_data)

Parses and evaluates a JSONPath expression against the provided JSON data.

parse(expression)

Parses a JSONPath expression into an Abstract Syntax Tree (AST).

Functions

evaluate(expression, json_data)

Parses and evaluates a JSONPath expression against the provided JSON data.

Combines parsing and evaluation into a single step. Returns the result of the evaluation or an error tuple if parsing or evaluation fails.

Parameters

  • expression (String): A valid JSONPath expression.
  • json_data (Map or List): The JSON data to query.

Examples 

iex> json_data = %{
...>   "store" => %{
...>     "book" => [
...>       %{"title" => "Elixir in Action"},
...>       %{"title" => "Programming Elixir"}
...>     ]
...>   }
...> }
iex> JSONPathEx.evaluate("$.store.book[*].title", json_data)
{:ok, ["Elixir in Action", "Programming Elixir"]}

Errors 

iex> JSONPathEx.evaluate("$.invalid[", %{})
{:error, "Invalid JSONPath expression"}

Notes

  • This function ensures that both parsing and evaluation are performed in sequence.
  • For debugging purposes, consider using JsonpathEx.Parser and JsonpathEx.Evaluator separately.

parse(expression)

Parses a JSONPath expression into an Abstract Syntax Tree (AST).

This function is useful for debugging or when you want to inspect the structure of a JSONPath expression without evaluating it.

Parameters

  • expression (String): A valid JSONPath expression.

Examples 

iex> JSONPathEx.parse("$.store.book[*].title")
{:ok, [root: "$", dot_child: ["store"], dot_child: ["book"], array: [array_wildcard: {:wildcard, "*"}], dot_child: ["title"]]}