gson-query

Json Query

Install

npm i gson-query

and use with

const query = require("gson-query")

At first, json-query acts like a normal json-pointer where its match is passed to the given callback function:

	const query = require("gson-query");
	const data = {
		"parent": {
			"child": {"id": "child-1"}
		}
	};
	query.run(data, "#/parent/child/id", (value, key, object, jsonPointer) => {
		// value = "child-1"
		// key = "id"
		// object = {"id": "child-1"}
		// jsonPointer = "#/parent/child/id"
	});
	// or get the result in an array
	var match = query.get(data, "#/parent/child/id");
	// [ ["child-1", "id", {"id":"child-1"}, "#/parent/child/id"] ]

But query also supports glob-patterns with *:

	const query = require("gson-query");
	const data = {
		"parent": {
			"child": {"id": "child-1"}
		},
		"neighbour": {
			"child": {"id": "child-2"}
		}
	};
	query.run(data, "#/*/child/id", function (value, key, object, jsonPointer) {
		// will be called with value: "child-1" and "child-2"
	});
	// or get the result in an array
	var match = query.get(data, "#/parent/child/id");
	// [ ["child-1", ...], ["child-2", ...] ]

and glob-patterns with **:

	var query = require("gson-query");
	var data = {
		"parent": {
			"child": {"id": "child-1"}
		},
		"neighbour": {
			"child": {"id": "child-2"}
		}
	};
	query.run(data, "#/**/id", function (value, key, object, jsonPointer) {
		// will be called with value: "parent" "child-1" and "child-2"
	});

or simply call query.run(data, "#/**", callback) to run callback on each object,array and value.

To filter the matched objects, an object-query string may be appended on each single step:

	var query = require("gson-query");
	var data = {
		"parent": {
			"valid": true,
			"child": {"id": "child-1"}
		},
		"neighbour": {
			"valid": false,
			"child": {"id": "child-2"}
		},
		"dungeons": {
			"child": {"id": "child-3"}
		}
	};
	query.run(data, "#/**?valid:true&&ignore:undefined/child", function (value, key, object, jsonPointer) {
		// will be called with value: {"id": "child-1"} only
	});
	// same result with
	query.run(data, "#/**?valid:!false/child", function (value, key, object, jsonPointer) { // ...

or match all objects that have a defined property valid like query.run(data, "#/**?valid", callback).

regular expression must be wrapped with {.*}:

	var query = require("gson-query");
	var data = {
		"albert": {valid: true},
		"alfred": {valid: false},
		"alfons": {valid: true}
	};
	query.run(data, "#/{al[^b]}?valid:true", function (value, key, object, jsonPointer) {
		// will be executed with value: alfons
	});

queryGet

If you only require values or pointers, use queryGet to receive an Array or Object as result:

	var queryGet = require("gson-query").get;

	// default: queryGet.VALUES
	var arrayOfValues = queryGet(data, "#/**/id", queryGet.VALUE);
	// ["#/..", "#/..", ...]
	var arrayOfJsonPointers = queryGet(data, "#/**/id", queryGet.POINTER);
	// [arguments, arguments], where arguments = 0:value 1:object 2:key 3:jsonPointer
	var arrayOfAllFourArguments = queryGet(data, "#/**/id", queryGet.ALL);
	// {"#/..": value, "#/..": value}
	var mapOfPointersAndData = queryGet(data, "#/**/id", queryGet.MAP);

queryDelete

Multiple items on objects or in arrays may also be delete with query.delete:

	var queryDelete = require("gson-query").delete;

	queryDelete(data, "#/**/*/data");

Examples

• query.run(data, "#/**/*", callback); will iterate over each value of the data object
• query.run(data, "#/**?valid:true", callback); will select all objects having its property "valid" set to true

for further examples refer to the unit tests

• query.delete
• query.get
• query.query