JavaScript object query language, and a library to process and perform Jora queries on data.
STATUS: Jora is stable, but syntax may change in next releases. Still very much work in progress (ideas and thoughts).
Features:
- Tolerant to data stucture queries (e.g. just returns nothing for paths that not reachable)
- Compact syntax for common tasks
- Aggregate values across arrays and eliminate duplicates by default
- Stat collecting mode (powers suggestions)
- Tolerant parsing mode (useful to provide suggestions for query in an editor)
- Extensible DSL on query build by custom method list
Related projects:
- Discovery – Uses jora as core fuctionality to transform a data flow for views and query data for reports
- JsonDiscovery – a browser’s extension based on Discovery for viewing JSON documents, available for Chrome and Firefox (read more Changing a way we’re viewing JSON in a browser)
- jora-cli – Command line interface for transforming data using Jora
- Jora sandbox – A Web interface where you can play with jora syntax or transform some JSON with zero setup
Table of content:
Jora is a query language designed for JSON-like data structures. It extends JSON5 and shares many similarities with JavaScript.
See Docs & playground.
// single-line comment
/* multi-line
comment */
Jora expressions are the building blocks of Jora queries. Expressions can include comments, literals, operators, functions, and variables.
Jora supports literals, which include:
- Numbers:
42
,-3.14
,6.022e23
- Strings:
"hello"
,'world'
,`template${yes}`
,"\u{1F600}"
- Booleans:
true
,false
- Regular expressions:
/regexp/flags
- Object literals:
{ hello: 'world' }
(see Object literals) - Array literals:
[1, 2, 3]
(see Array literals) - Functions:
=> …
(see Functions) - Keywords:
NaN
,Infinity
,null
andundefined
See Literals
Jora supports most JavaScript operators, including:
- Arithmetic:
+
,-
,*
,/
,%
- Comparison:
=
,!=
,<
,<=
,>
,>=
,~=
- Logical:
and
,or
,not
(aliasno
),??
,is
,in
,not in
,has
,has no
- Ternary:
?:
- Grouing:
( )
- Pipeline:
|
See Operators
Jora provides notations for accessing properties and elements: dot, bracket and slice notations. Dot notation is similar to JavaScript's property access notation, using a period followed by the property name (e.g., $.propertyName
). Bracket notation encloses the property name or index within square brackets (e.g., $['propertyName']
or $[0]
), it's also possible to use functions to choose. Slice notation provides a concise syntax to slice elements with optional step (array[5:10:2]
selects each odd element from 5th to 10th indecies).
Jora provides a rich set of built-in methods for manipulating data, such as map()
, filter()
, group()
, sort()
, reduce()
, and many others. You can also define custom functions using the =>
arrow function syntax, and use them as a method.
- Functions
- Methods
- Built-in methods
- Grouping:
group()
method - Sorting:
sort()
method
Jora has a concise syntax for mapping and filtering. The map(fn)
method is equivalent to .(fn())
, while the filter(fn)
method is equivalent to .[fn()]
.
- Filtering:
.[…]
andfilter()
method - Mapping:
.(…)
andmap()
method - Recursive mapping:
..(…)
Variables in Jora are helpful for storing intermediate results or simplifying complex expressions. To define a variable, use the $variableName: expression;
syntax.
See Variables
Install with npm:
npm install jora
Basic usage:
// ESM
import jora from 'jora';
// CommonJS
const jora = require('jora');
Bundles are available for use in a browser:
dist/jora.js
– minified IIFE withjora
as global
<script src="node_modules/jora/dist/jora.js"></script>
<script>
jora('query')(data, context);
</script>
dist/jora.esm.js
– minified ES module
<script type="module">
import jora from 'node_modules/jora/dist/jora.esm.js'
// ...
</script>
By default (for short path) a ESM version is exposing. For IIFE version a full path to a bundle should be specified. One of CDN services like unpkg
or jsDelivr
can be used:
-
jsDeliver
<!-- ESM --> <script type="module"> import jora from 'https://cdn.jsdelivr.net/npm/jora'; </script>
<!-- IIFE with an export `jora` to global --> <script src="https://cdn.jsdelivr.net/npm/jora/dist/jora.js"></script>
-
unpkg
<!-- ESM --> <script type="module"> import jora from 'https://unpkg.com/jora'; </script>
<!-- IIFE with an export `jora` to global --> <script src="https://unpkg.com/jora/dist/jora.js"></script>
import jora from 'jora';
// create a query
const query = jora('foo.bar');
// perform a query
const result = query(data, context);
See the details in Jora library API
Get npm dependency paths (as a tree) that have packages with more than one version:
import jora from 'jora';
import { exec } from 'child_process';
function printTree() {
// see implementation in examples/npm-ls.js
}
exec('npm ls --all --json', (error, stdout) => {
if (error) {
return;
}
const npmTree = JSON.parse(stdout);
const depsPathsToMultipleVersionPackages = jora(`
$normalizedDeps: => dependencies.entries().({ name: key, ...value });
$multiVersionPackages:
..$normalizedDeps()
.group(=>name, =>version)
.({ name: key, versions: value.sort() })
.[versions.size() > 1];
$pathToMultiVersionPackages: => .($name; {
name,
version,
otherVersions: $multiVersionPackages[=>name=$name].versions - version,
dependencies: $normalizedDeps()
.$pathToMultiVersionPackages()
.[name in $multiVersionPackages.name or dependencies]
});
$pathToMultiVersionPackages()
`)(npmTree);
printTree(depsPathsToMultipleVersionPackages);
});
Example of output:
jora@1.0.0
├─ c8@7.11.0
│ ├─ istanbul-lib-report@3.0.0
│ │ └─ supports-color@7.2.0 [more versions: 8.1.1]
│ ├─ test-exclude@6.0.0
│ │ └─ minimatch@3.1.2 [more versions: 3.0.4]
│ ├─ v8-to-istanbul@8.1.1
│ │ └─ convert-source-map@1.8.0
│ │ └─ safe-buffer@5.1.2 [more versions: 5.2.1]
│ ├─ yargs-parser@20.2.9 [more versions: 20.2.4]
│ └─ yargs@16.2.0
│ └─ yargs-parser@20.2.9 [more versions: 20.2.4]
├─ eslint@8.10.0
│ ├─ @eslint/eslintrc@1.2.0
│ │ ├─ ignore@4.0.6 [more versions: 5.2.0]
│ │ └─ minimatch@3.1.2 [more versions: 3.0.4]
...
See more examples in Complex Jora query examples