Monger

Monger is an idiomatic Clojure wrapper around MongoDB Java driver. It offers powerful expressive query DSL, strives to support every MongoDB 2.0+ feature and is well maintained.

Project Goals

There is one MongoDB client for Clojure that has been around since 2009. So, why create another one? Monger authors wanted a client that will

• Support most of MongoDB 2.0+ features but only those that really matter. Grouping the way it is done today, for example, does not (it is easier to just use Map/Reduce directly).
• Be well documented.
• Be well tested.
• Be maintained, not carry technical debt from 2009 forever.
• Integrate with libraries like clojure.data.json and Joda Time.
• Integrate usage of JavaScript files and ClojureScript (as soon as the compiler gets artifact it is possible to depend on for easy embedding).
• Learn from other clients like the Java and Ruby ones.
• Target Clojure 1.3.0 and later from the ground up.

Usage

We are working on documentation guides & examples site for the 1.0 release. In the meantime, please refer to the test suite for code examples.

Powerful Query DSL

Every application that works with data stores has to query them. As a consequence, having an expressive powerful query DSL is a must for client libraries like Monger.

Here is what monger.query DSL feels like:

(with-collection "docs"
  (find { :inception_year { $lt 2000 $gte 2011 } })
  (fields { :inception_year 1 :name 1 })
  (skip 10)
  (limit 20)
  (batch-size 50)
  (hint "my-index-name")
  (snapshot))

It is easy to add new DSL elements, for example, adding pagination took literally less than 10 lines of Clojure code. Here is what it looks like:

(with-collection coll
                  (find {})
                  (paginate :page 1 :per-page 3)
                  (sort { :title 1 })
                  (read-preference ReadPreference/PRIMARY))

Query DSL supports composition, too:

(let
    [top3               (partial-query (limit 3))
     by-population-desc (partial-query (sort { :population -1 }))
     result             (with-collection coll
                          (find {})
                          (merge top3)
                          (merge by-population-desc))]
  ;; ...
  )

More code examples can be found in our test suite.

This is a Work In Progress

Core Monger APIs are stabilized but it is still a work in progress. Keep that in mind. 1.0 will be released in late 2011.

Artifacts

Snapshot artifacts are released to Clojars every 24 hours.

With Leiningen:

[com.novemberain/monger "1.0.0-SNAPSHOT"]

With Maven:

<dependency>
  <groupId>com.novemberain</groupId>
  <artifactId>monger</artifactId>
  <version>1.0.0-SNAPSHOT</version>
</dependency>

Continuous Integration

CI is hosted by travis-ci.org.

Supported Clojure versions

Monger is built from the ground up for Clojure 1.3 and up.

License

Copyright (C) 2011 Michael S. Klishin

Distributed under the Eclipse Public License, the same as Clojure.