node-jq is a wrapper for jq - a lightweight and flexible command-line JSON processor.
npm install node-jq --saveUsually in your CLI with jq you would run:
jq ".abilities[].moves" bulbasaur.jsonand you would get
{
"name": "heartgold-soulsilver",
"power": "10"
}
{
"name": "platinum",
"power": "50"
}
{
"name": "diamond-pearl",
"power": "99"
}With node-jq you could run it programmatically and interact with the output as a JavaScript Object:
constjq=require('node-jq')constfilter='.abilities[].moves'constjsonPath='/path/to/bulbasaur.json'constoptions={}jq.run(filter,jsonPath,options).then((output)=>{console.log(output)/* { "name": "heartgold-soulsilver", "power": "10" }, { "name": "platinum", "power": "50" }, { "name": "diamond-pearl", "power": "99" } */}).catch((err)=>{console.error(err)// Something went wrong...})| Description | Type | Values | Default |
|---|---|---|---|
| Type of input | string | 'file', 'json', 'string' | 'file' |
Run the jq query against a JSON file.
jq.run('.','/path/to/file.json').then(console.log)// {// "foo": "bar"// }Run jq query against multiple JSON files.
jq.run('.',['/path/to/file.json','path/to/other_file.json']).then(console.log)// {// "foo": "bar"// }// {// "otherFoo": "andBar"// }Run the jq query against an Object.
jq.run('.',{foo: 'bar'},{input: 'json'}).then(console.log)// {// "foo": "bar"// }Run the jq query against a String.
jq.run('.','{ foo: "bar" }',{input: 'string'}).then(console.log)// {// "foo": "bar"// }| Description | Values | Default |
|---|---|---|
| Type of output | 'pretty', 'json', 'compact', 'string' | 'pretty' |
Return the output as a String.
jq.run('.','/path/to/file.json',{output: 'string'}).then(console.log)// {// "foo": "bar"// }Return the output as an Object.
jq.run('.','/path/to/file.json',{output: 'json'}).then(console.log)// { foo: 'bar' }Return the output as a String.
jq.run('.','/path/to/file.json',{output: 'compact'}).then(console.log)// {"foo":"bar"}jq.run('.','/path/to/file.json',{output: 'string'}).then(console.log)// {"foo":"bar"}| Description | Values | Default |
|---|---|---|
| Read input stream into array | true, false | false |
Read input stream into array.
jq.run('.',['/path/to/file.json','/path/to/other_file.json'],{output: 'json',slurp: true}).then(console.log)// [// {// "foo": "bar"// },// {// "otherFoo": "andBar"// }// ]| Description | Values | Default |
|---|---|---|
| Sort object keys in alphabetical order | true, false | false |
Sorts object keys alphabetically.
jq.run('.',['/path/to/file.json'],{output: 'json',sort: true}).then(console.log)// {// "a": 2,// "b": 1// },- atom-jq: an Atom package for manipulating JSON
- json-splora: an Electron implementation for manipulating JSON
Why would you want to manipulate JavaScript Objects with jq syntax in a node app, when there are tools like lodash?
The idea was to port jq in node to be able to run it as-is. node-jq doesn't try to replace Object filters, maps, or transformations.
Our primary goal was to make jq syntax available in Atom with atom-jq.
Other than that, jq is an interesting CLI tool to quickly parse the response of an API, such as:
curl 'https://jsonplaceholder.typicode.com/comments'| jq '.[].postId'There are also people dealing with complex responses:
- ilya-sher.org/2016/05/11/most-jq-you-will-ever-need
- cloudadvantage.com.au/new-aws-command-line-tool-and-jq
Seems hard to learn, but it really isn't.
jq is like sed for JSON. Slice, filter, map and transform structured data in a simple and powerful way.
Take a look at this great introduction or a jq lesson.
You can check out the official manual and fiddle around in the online playground jqplay.org.