js-jsonq

js-jsonq is a simple, elegant Javascript package to Query over any type of JSON Data. It'll make your life easier by giving the flavour of an ORM-like query on your JSON.

This package is inspired from the awesome jsonq package.

Installation

npm install js-jsonq

or

yarn add js-jsonq

Usage

Just import/require the package before start using it.

As a Node.js Package:

const jsonQ = require('js-jsonq');

As a ES6 Module:

import jsonQ from 'js-jsonq';

You can start using this package right away by importing your Json data from a file:

new jsonQ('data.json');

Or from a Json String:

new jsonQ('{"id": 1, "name": "shaon"}');

Or from a Json Object:

new jsonQ({ id: 1, name: 'shaon' });

You can start Query your data using the various query methods such as find, where, orWhere, whereIn, whereStartsWith, whereEndsWith, whereContains and so on. Also you can aggregate your data after query using sum, count, groupBy, max, min etc.

Let's see a quick example:

// sample Json data
const JsonObject = {
    products: [
        {
            id: 1,
            city: 'bsl',
            name: 'iPhone',
            cat: 1,
            price: 80000.5
        },
        {
            id: 2,
            city: null,
            name: 'macbook pro',
            cat: 1,
            price: 150000
        },
        {
            id: 3,
            city: 'dhk',
            name: 'Redmi 3S Prime',
            cat: 2,
            price: 12000
        },
        {
            id: 4,
            city: 'bsl',
            name: 'macbook air',
            cat: 2,
            price: 110000
        }
    ]
};

const Q = new jsonQ(JsonObject);
const res = Q.from('products')
    .where('cat', '=', 2)
    .fetch();
console.log(res);

//This will print
/*
[
    {
        id: 3,
        city: 'dhk',
        name: 'Redmi 3S Prime',
        cat: 2,
        price: 12000
    },
    {
        id: 4,
        city: 'bsl',
        name: 'macbook air',
        cat: 2,
        price: 110000
    }
]
*/

Let's say we want to get the Summation of price of the Queried result. We can do it easily by calling the sum() method instead of fetch():

const res = Q.from('products')
    .where('cat', '=', 2)
    .sum('price');
console.log(res);
//It will print:
/*
122000
*/

Pretty neat, huh?

Let's explore the full API to see what else magic this library can do for you. Shall we?

API

Following API examples are shown based on the sample JSON data given here. To get a better idea of the examples see that JSON data first. Also detailed examples of each API can be found here.

List of API:

• fetch
• find
• at
• from
• where
• orWhere
• whereIn
• whereNotIn
• whereNull
• whereNotNull
• whereStartsWith
• whereEndsWith
• whereContains
• sum
• count
• size
• max
• min
• avg
• first
• last
• nth
• exists
• groupBy
• sort
• sortBy
• reset
• copy

fetch()

This method will execute queries and will return the resulted data. You need to call it finally after using some query methods. Details can be found in other API examples.

find(path)

• path -- the path hierarchy of the data you want to find.

You don't need to call fetch() method after this. Because this method will fetch and return the data by itself.

caveat: You can't chain further query methods after it. If you need that, you should use at() or from() method.

example:

Let's say you want to get the value of 'cities' property of your Json Data. You can do it like this:

const Q = new jsonQ(JsonObject).find('cities');

If you want to traverse to more deep in hierarchy, you can do it like:

const Q = new jsonQ(JsonObject).find('cities.1.name');

See a detail example here.

at(path)

• path (optional) -- the path hierarchy of the data you want to start query from.

By default, query would be started from the root of the JSON Data you've given. If you want to first move to a nested path hierarchy of the data from where you want to start your query, you would use this method. Skipping the path parameter or giving '.' as parameter will also start query from the root Data.

Difference between this method and find() is that, find() method will return the data from the given path hierarchy. On the other hand, this method will return the Object instance, so that you can further chain query methods after it.

example:

Let's say you want to start query over the values of 'users' property of your Json Data. You can do it like this:

const Q = new jsonQ(JsonObject).at('users').where('id', '=', 1).fetch();

If you want to traverse to more deep in hierarchy, you can do it like:

const Q = new jsonQ(JsonObject).at('users.5.visits').where('year', '=', 2011).fetch();

See a detail example here.

from(path)

This is an alias method of at() and will behave exactly like that. See example here.

where(key, op, val)

• key -- the property name of the data. Or you can pass a Function here to group multiple query inside it. See details in example

• val -- value to be matched with. It can be a int, string, bool or even Function - depending on the op.

• op -- operand to be used for matching. The following operands are available to use:

  • = : For weak equality matching
  • eq : Same as =
  • != : For weak not equality matching
  • neq : Same as !=
  • == : For strict equality matching
  • seq : Same as ==
  • !== : For strict not equality matching
  • sneq : Same as !==
  • > : Check if value of given key in data is Greater than val
  • gt : Same as >
  • < : Check if value of given key in data is Less than val
  • lt : Same as <
  • >= : Check if value of given key in data is Greater than or Equal of val
  • gte : Same as >=
  • <= : Check if value of given key in data is Less than or Equal of val
  • lte : Same as <=
  • null : Check if the value of given key in data is null (val parameter in where() can be omitted for this op)
  • notnull : Check if the value of given key in data is not null (val parameter in where() can be omitted for this op)
  • in : Check if the value of given key in data is exists in given val. val should be a plain Array.
  • notin : Check if the value of given key in data is not exists in given val. val should be a plain Array.
  • startswith : Check if the value of given key in data starts with (has a prefix of) the given val. This would only works for String type data.
  • endswith : Check if the value of given key in data ends with (has a suffix of) the given val. This would only works for String type data.
  • contains : Check if the value of given key in data has a substring of given val. This would only works for String type data.
  • match : Check if the value of given key in data has a Regular Expression match with the given val. The val parameter should be a RegExp for this op.
  • macro : It would try to match the value of given key in data executing the given val. The val parameter should be a Function for this op. This function should have a matching logic inside it and return true or false based on that.

example:

Let's say you want to find the 'users' who has id of 1. You can do it like this:

const Q = new jsonQ(JsonObject).from('users').where('id', '=', 1).fetch();

You can add multiple where conditions. It'll give the result by AND-ing between these multiple where conditions.

const Q = new jsonQ(JsonObject).from('users').where('id', '=', 1).where('location', '=', 'Sylhet').fetch();

See a detail example here.

orWhere(key, op, val)

Parameters of orWhere() are the same as where(). The only difference between where() and orWhere() is: condition given by the orWhere() method will OR-ed the result with other conditions.

For example, if you want to find the users with id of 1 or 2, you can do it like this:

const Q = new jsonQ(JsonObject).from('users').where('id', '=', 1).orWhere('id', '=', 2).fetch();

See detail example here.

whereIn(key, val)

• key -- the property name of the data
• val -- it should be an Array

This method will behave like where(key, 'in', val) method call.

whereNotIn(key, val)

• key -- the property name of the data
• val -- it should be an Array

This method will behave like where(key, 'notin', val) method call.

whereNull(key)

• key -- the property name of the data

This method will behave like where(key, 'null') or where(key, '=', null) method call.

whereNotNull(key)

• key -- the property name of the data

This method will behave like where(key, 'notnull') or where(key, '!=', null) method call.

whereStartsWith(key, val)

• key -- the property name of the data
• val -- it should be a String

This method will behave like where(key, 'startswith', val) method call.

whereEndsWith(key, val)

• key -- the property name of the data
• val -- it should be a String

This method will behave like where(key, 'endswith', val) method call.

whereContains(key, val)

• key -- the property name of the data
• val -- it should be a String

This method will behave like where(key, 'contains', val) method call.

sum(property)

• property -- the property name of the data

example:

Let's say you want to find the sum of the 'price' of the 'products'. You can do it like this:

const Q = new jsonQ(JsonObject).from('products').sum('price').fetch();

If the data you are aggregating is plain array, you don't need to pass the 'property' parameter. See detail example here

count()

It will return the number of elements in the collection.

example:

Let's say you want to find how many elements are in the 'products' property. You can do it like:

const Q = new jsonQ(JsonObject).from('products').count();

See detail example here.

size()

This is an alias method of count().

max(property)

• property -- the property name of the data

example:

Let's say you want to find the maximum of the 'price' of the 'products'. You can do it like this:

const Q = new jsonQ(JsonObject).from('products').max('price').fetch();

If the data you are querying is plain array, you don't need to pass the 'property' parameter. See detail example here

min(property)

• property -- the property name of the data

example:

Let's say you want to find the minimum of the 'price' of the 'products'. You can do it like this:

const Q = new jsonQ(JsonObject).from('products').min('price').fetch();

If the data you are querying is plain array, you don't need to pass the 'property' parameter. See detail example here

avg(property)

• property -- the property name of the data

example:

Let's say you want to find the average of the 'price' of the 'products'. You can do it like this:

const Q = new jsonQ(JsonObject).from('products').avg('price').fetch();

If the data you are querying is plain array, you don't need to pass the 'property' parameter. See detail example here

first()

It will return the first element of the collection.

example:

const Q = new jsonQ(JsonObject).from('products').first();

See detail example here.

last()

It will return the last element of the collection.

example:

const Q = new jsonQ(JsonObject).from('products').last();

See detail example here.

nth(index)

• index -- index of the element to be returned.

It will return the nth element of the collection. If the given index is a positive value, it will return the nth element from the beginning. If the given index is a negative value, it will return the nth element from the end.

example:

const Q = new jsonQ(JsonObject).from('products').nth(2);

See detail example here.

exists()

It will return true if the element is not empty or not null or not an empty array or not an empty object.

example:

Let's say you want to find how many elements are in the 'products' property. You can do it like:

const Q = new jsonQ(JsonObject).from('products').count();

See detail example here.

groupBy(property)

• property -- The property by which you want to group the collection.

example:

Let's say you want to group the 'users' data based on the 'location' property. You can do it like:

const Q = new jsonQ(JsonObject).from('users').groupBy('location').fetch();

See detail example here.

sort(order)

• order -- If you skip the 'order' property the data will be by default ordered as ascending. You need to pass 'desc' as the 'order' parameter to sort the data in descending order. Also, you can pass a compare function in 'order' parameter to define your own logic to order the data.

Note: This method should be used for plain Array. If you want to sort an Array of Objects you should use the sortBy() method described later.

example:

Let's say you want to sort the 'arr' data. You can do it like:

const Q = new jsonQ(JsonObject).from('arr').sort().fetch();

See detail example here.

sortBy(property, order)

• property -- You need to pass the property name on which the sorting will be done.
• order -- If you skip the 'order' property the data will be by default ordered as ascending. You need to pass 'desc' as the 'order' parameter to sort the data in descending order. Also, you can pass a compare function in 'order' parameter to define your own logic to order the data.

Note: This method should be used for Array of Objects. If you want to sort a plain Array you should use the sort() method described earlier.

example:

Let's say you want to sort the 'price' data of 'products'. You can do it like:

const Q = new jsonQ(JsonObject).from('products').sortBy('price').fetch();

See detail example here.

reset(data)

• data -- can be a JSON file path, or a JSON string or a JSON Object. If no data passed in the data parameter, the jsonQ Object instance will be reset to previously initialized data.

At any point, you might want to reset the Object instance to a completely different set of data and then query over it. You can use this method in that case.

See a detail example here.

copy()

It will return a complete clone of the Object instance.

See a detail example here.

Bugs and Issues

If you encounter any bugs or issues, feel free to open an issue at github.

Also, you can shoot me an email to mailto:[email protected] for hugs or bugs.

Credit

Speical thanks to Nahid Bin Azhar for the inspiration and guidance for the package.