mongodb-language-model

mongodb-language-model

Parses a MongoDB query and creates hierarchical Ampersand.js models for each of the language components, which can then be interacted with programmatically.

UML diagram

This is the hierarchical model that is created when a query is parsed:

Example

var Query = require('mongodb-language-model').Query;
var assert = require('assert');

// you need to specify `{parse: true}` if a raw javascript object is provided
var query = new Query(
    {"foo": 12345, "$and": [ {bar: false}, {baz: "hello"} ] }, 
    {parse: true}
);

// two top-level clauses
assert.equal(query.clauses.length, 2);

// access leaf clause
var leafClause = query.clauses.get('foo');
assert.equal(leafClause.className, 'LeafClause');

// LeafClause provides access to key and value objects. To access the their 
// native values, they need to be serialized.
assert.equal(leafClause.key.serialize(), 'foo');
assert.equal(leafClause.value.serialize(), 12345);

// access the $and expression tree
var exprTree = query.clauses.get('$and');
assert.equal(exprTree.className, 'ExpressionTree');

// get the list of clause keys
var keys = exprTree.expressions.map(function (expr) {
    return expr.clauses.at(0).key.serialize();
});
assert.deepEqual(keys, ['bar', 'baz']);

// get the list of clause values
var values = exprTree.expressions.map(function (expr) {
    return expr.clauses.at(0).value.serialize();
})
assert.deepEqual(values, [false, 'hello']);

Installation

// @todo
npm install --save mongodb-language-model

Testing

npm test

License

Apache 2.0