als-json-filter

als-json-filter is a versatile utility for filtering JSON objects based on a variety of conditions, similar to querying databases but applicable in general JavaScript environments. This package allows users to apply complex query conditions to JSON data structures, making it ideal for data processing tasks in both frontend and backend applications.

Installation

Install the package via npm:

npm install als-json-filter

Usage

To use als-json-filter, import the function and define your filter criteria:

const createFilter = require('als-json-filter');

const filter = createFilter({
    age: { $gt: 18, $lt: 65 },
    name: { $regex: '^[a-zA-Z]+$' }
});

const data = [
    { name: 'Alice', age: 25 },
    { name: 'Bob', age: 17 },
    { name: 'Charlie', age: 70 }
];

const filteredData = data.filter(filter);
console.log(filteredData);

This will output:

[
    { name: 'Alice', age: 25 }
]

Examples of Filter Operators

Greater Than ($gt)

const filter = createFilter({ age: { $gt: 30 } });
console.log(filter({ age: 31 })); // true
console.log(filter({ age: 30 })); // false

Less Than or Equal To ($lte)

const filter = createFilter({ age: { $lte: 20 } });
console.log(filter({ age: 20 })); // true
console.log(filter({ age: 21 })); // false

Regex Match ($regex)

const filter = createFilter({ username: { $regex: '^[a-z0-9_-]{3,16}$' } });
console.log(filter({ username: 'user_123' })); // true
console.log(filter({ username: 'not_valid!' })); // false

Logical OR ($or)

const filter = createFilter({
    $or: [
        { age: { $lt: 20 } },
        { age: { $gt: 50 } }
    ]
});
console.log(filter({ age: 18 })); // true
console.log(filter({ age: 30 })); // false
console.log(filter({ age: 60 })); // true

Property Exists ($exists)

const filter = createFilter({ email: { $exists: true } });
console.log(filter({ email: '[e-mail]' })); // true
console.log(filter({ username: 'user123' })); // false

Type Matching ($type)

const filter = createFilter({ count: { $type: 'number' } });
console.log(filter({ count: 10 })); // true
console.log(filter({ count: 'ten' })); // false

Supported Filter Operators

als-json-filter supports a range of operators, similar to those found in MongoDB:

• $gt: Greater than
• $gte: Greater than or equal to
• $lt: Less than
• $lte: Less than or equal to
• $eq: Equal
• $ne: Not equal
• $in: Included in an array
• $nin: Not included in an array
• $regex: Matches regex
• $or: Logical OR
• $and: Logical AND
• $not: Logical NOT
• $nor: Logical NOR
• $exists: Property exists
• $type: Type of property matches

License

als-json-filter is MIT licensed.