README.md

JSONPath Extraction

JSONPath Extract is a Visual Studio Code extension that allows you to extract parts of a JSON document using a JSONPath query.

Features

Currently there are three commands, all can be accessed via Ctrl + Shift + P (Cmd + Alt + P on Mac) typing JPE.

JPE: Run jsonpath query - plaintext

This command asks for a JSONPath query, runs it on the currently opened document and then pastes the results to a new file, each result on a separate line.

JPE: Run jsonpath query - json

This command works just like JPE: Run jsonpath query - plaintext, except that results are pasted as a JSON array to a new file.

JPE: Run saved jsonpath query

If you find yourself typing the same query over and over, you can use this command to run prepared queries from a configuration. You need to define your queries in either your user or workspace configuration. If you want to run $.store.book[?(@.category == "fiction")].title to get titles of all fiction books and extract them to JSON array, you can create the following configuration.

{
    "jsonPathExtract.savedQueries": [
        {
            "output": "json",
            "query": "$.store.book[?(@.category == \"fiction\")].title",
            "title": "Titles of all fictional books"
        }
    ]
}

JSONPath basics

JSONPath was originally introduced by Stefan Goessner in 2007.

JSONPath	Description
$	The outer level object / array
@	The current object / element
.name or ["name"]	The child member operator (access value of key "name")
..	Recursive descent
*	Wildcard matching all objects / elements regardless of their names.
.*~	Wildcard matching all keys
[name1, name2, ...]	Subscript operator for multiple names or array indices as a set
[start : end : step]	Slice operator
?()	Applies a filter (script) expression via static evaluation
()	Script expression via static evaluation

Let's explore the JSONPath expressions on example JSON file representing a bookstore.

{
  "store": {
      "book": [
          {
              "category": "reference",
              "author": "Nigel Rees",
              "title": "Sayings of the Century",
              "price": 8.95
          },
          {
              "category": "fiction",
              "author": "Evelyn Waugh",
              "title": "Sword of Honour",
              "price": 12.99
          },
          {
              "category": "fiction",
              "author": "Herman Melville",
              "title": "Moby Dick",
              "isbn": "0-553-21311-3",
              "price": 8.99
          },
          {
              "category": "fiction",
              "author": "J. R. R. Tolkien",
              "title": "The Lord of the Rings",
              "isbn": "0-395-19395-8",
              "price": 22.99
          }
      ],
      "bicycle": {
          "color": "red",
          "price": 19.95
      }
  }
}

JSONPath	Result
$.store.book[*].author	The authors of all books in the store
$..author	All authors
$.store.*	All things in the store (books and a bicycle)
$..book[?(@.price<10)]	All books cheaper than 10
$..book[:2]	The first two books
$..book[(@.length-1)]	The last book
$.store.*~	The names of categories in the store

Credits

This extension uses dchester/jsonpath library for processing JSONPath queries.