https://github.com/blmoore/rjsonpath

JSONPath for R
https://github.com/blmoore/rjsonpath

json jsonpath r rstats

Last synced: 9 months ago
JSON representation

JSONPath for R

• Host: GitHub
• URL: https://github.com/blmoore/rjsonpath
• Owner: blmoore
• License: mit
• Created: 2017-05-16T06:24:08.000Z (almost 9 years ago)
• Default Branch: master
• Last Pushed: 2017-06-03T22:35:33.000Z (almost 9 years ago)
• Last Synced: 2025-03-30T14:11:37.228Z (12 months ago)
• Topics: json, jsonpath, r, rstats
• Language: R
• Homepage: http://blm.io/rjsonpath
• Size: 48.8 KB
• Stars: 12
• Watchers: 1
• Forks: 1
• Open Issues: 3
• Metadata Files:
  • Readme: README.Rmd
  • License: LICENSE

Awesome Lists containing this project

README

          
---

output: github_document

---

```{r, echo = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "README-"

)

```

# rjsonpath

[![travis_status](https://travis-ci.org/blmoore/rjsonpath.svg?branch=master)](https://travis-ci.org/blmoore/rjsonpath)

[![codecov](https://codecov.io/gh/blmoore/rjsonpath/branch/master/graph/badge.svg)](https://codecov.io/gh/blmoore/rjsonpath)

[![docs_badge](https://img.shields.io/badge/docs-latest-blue.svg)](http://blm.io/rjsonpath)

[![CRAN_badge](http://www.r-pkg.org/badges/version/rjsonpath)](https://cran.r-project.org/package=rjsonpath)

Reading JSON into R usually leaves you with some deeply-nested

list objects which are a pain to munge and navigate — applying path

expressions is one way to make this easier. `rjsonpath` implements

[JSONPath](http://goessner.net/articles/JsonPath/), a 

selector / querying language for JSON, similar to XPath for 

XML.

## Install

Install from github with:

```{r eval=FALSE}

devtools::install_github("blmoore/rjsonpath")

```

## Usage

As an example, take this simple JSON:

```{javascript}

{"menu": {

  "id": "file",

  "value": "File",

  "popup": {

    "menuitem": [

      {"value": "New", "onclick": "CreateNewDoc()"},

      {"value": "Open", "onclick": "OpenDoc()"},

      {"value": "Close", "onclick": "CloseDoc()"}

    ]

  }

}}

```

```{r write_json_object, echo = FALSE}

json <- '{"menu": {

  "id": "file",

  "value": "File",

  "popup": {

    "menuitem": [

      {"value": "New", "onclick": "CreateNewDoc()"},

      {"value": "Open", "onclick": "OpenDoc()"},

      {"value": "Close", "onclick": "CloseDoc()"}

    ]

  }

}}'

json <- RJSONIO::fromJSON(json)

library(rjsonpath)

```

Via `read_json` this can be read into R as:

```{r}

json

```

Pretty horrible right? To gather all the `onclick` methods 

into a vector with base R you might write:

```{r}

sapply(json$menu$popup$menuitem, `[[`, "onclick")

```

Using `rjsonpath` this could instead be:

```{r, message=FALSE}

json_path(json, "$.menu.popup.menuitem[*].onclick")

```

Or even just:

```{r, message=FALSE}

json_path(json, "$..onclick")

```

For more more complex examples, see [below](#Advanced expressions).

## Advanced expressions