Awesome
jq-web
This is a WebAssembly build of jq, the command-line JSON processor.
It runs in the browser.
Installation and use
npm install jq-web
var jq = require('jq-web');
jq.then( jq => jq.json({
a: {
big: {
json: [
'full',
'of',
'important',
'things'
]
}
}
}, '.a.big.json | ["empty", .[1], "useless", .[3]] | join(" ")')
The code above returns the string "empty of useless things"
.
You could do the same using the promised API with jq.promised.json({...}).then(result => {})
. That is useful if you're loading a .mem
or .wasm
file, as the library won't return the correct results until these files are asynchronously fetched by the Emscripten runtime.
Webpack issues
fs
The Emscripten runtime will try to require
the fs
module, and if it fails it will resort to an in-memory filesystem (almost no use of that is made of the library, but it is needed somehow). In Browserify there's a default {}
that corresponds to the fs
module, but in Webpack you must declare it as an empty module.
404 error when loading .wasm
files
By default projects compiled with Emscripten look for .wasm
files in the same directory that the .js
file is run from. This causes issues when using webpack because name of the .wasm
file is altered with a hash and can be placed in a different directory. To fix this problem you can use the copy-webpack-plugin to copy the jq.wasm
file to the same directory that the webpack bundle is placed.
Reference
jq-web
exports a promise that resolves to an object with json
and raw
methods.
jq.json(<object>, <filter>) <object>
will take a Javascript object, or scalar, whatever, and dump it to JSON, then it will return whatever your filter outputs and try to convert that into a JS object.
jq.raw(<json-string>, <filter>, <flags>) <raw-output>
will take a string that will be passed as it is to jq (like if you were doing echo '<json-string>' | jq <filter>
on the command line) then return a string with the raw STDOUT response.
Build
- Install Emscripten. There have been several API changes over time; version 3.1.31 is known to work.
- Clone this repository, and
cd
into it. make
- This may take a while if you have never run Emscripten before.
Test
A handful of tests exist in test.js
. These are a good place to start when verifying a build.
To run them, do make test
.
You can test browser functionality by running:
./node_modules/live-server/live-server.js --open="index.html"
.