https://github.com/mongodb-js/mongodb-language-model

Parses MongoDB query language and creates hierarchical Ampersand.js models to interact with the query tree
https://github.com/mongodb-js/mongodb-language-model

ampersand compass-tools mongodb mongodb-query parser

Last synced: 8 days ago
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Parses MongoDB query language and creates hierarchical Ampersand.js models to interact with the query tree

• Host: GitHub
• URL: https://github.com/mongodb-js/mongodb-language-model
• Owner: mongodb-js
• License: apache-2.0
• Archived: true
• Created: 2015-06-15T04:56:22.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2021-05-09T22:51:37.000Z (over 3 years ago)
• Last Synced: 2024-08-01T19:45:19.949Z (4 months ago)
• Topics: ampersand, compass-tools, mongodb, mongodb-query, parser
• Language: JavaScript
• Size: 1.04 MB
• Stars: 34
• Watchers: 18
• Forks: 10
• Open Issues: 5
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# mongodb-language-model

[![build status](https://secure.travis-ci.org/mongodb-js/mongodb-language-model.png)](http://travis-ci.org/mongodb-js/mongodb-language-model)

Parses a MongoDB query and creates an abstract syntax tree (AST) with part of speech

tagging. Currently, only [strict extended json][docs-extended-json] syntax is

supported (which means keys have to be surrounded by double quotes and values

have to match the strict syntax of the extended-json format.);

## Usage

The main module exposes two functions: `accepts(queryStr)` and `parse(queryStr)`.

#### `accepts(queryStr)`

The `accepts(queryStr)` function takes a query string and returns `true` if the

string is a valid MongoDB query, `false` otherwise.

Example:

```javascript

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

var assert = require('assert');

assert.ok(accepts('{"foo": 1}'));

assert.ok(accepts('{"age": {"$gt": 35}}'));

assert.ok(accepts('{"$or": [{"email": {"$exists": true}}, {"phone": {"$exists": true}}]}'));

assert.equal(accepts('{"$invalid": "key"}'), false);

```

#### `parse(queryStr)`

The `parse(queryStr)` function takes a query string and returns an abstract

syntax tree (AST) as a javascript object, if the query is valid. If the

query is not valid, the function throws a `pegjs.SyntaxError` with a message

explaining the failure.

Example:

```javascript

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

var assert = require('assert');

var pegjs = require('pegjs');

var ast = parse('{"foo": "bar"}');

assert.deepEqual(ast, {

  'pos': 'expression',

  'clauses': [

    {

      'pos': 'leaf-clause',

      'key': 'foo',

      'value': {

        'pos': 'leaf-value',

        'value': 'bar'

      }

    }

  ]

});

```

## UML diagram

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

![](./docs/query_language_uml.png)

## Installation

```

npm install --save mongodb-language-model

```

## Testing

```

npm test

```

## License

Apache 2.0

[docs-extended-json]: https://docs.mongodb.com/manual/reference/mongodb-extended-json/