Skip to content


Subversion checkout URL

You can clone with
Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

513 lines (314 sloc) 17.8 KB

Changes between 1.0.0 and 1.1.0-alpha1

Alternative, Clojure reader-based Ring session store implementation

Monger 1.1 will have an alternative Ring session store uses Clojure reader serialization

This way libraries like Friend, that use namespaced keywords (like ::identity) and other Clojure-specific data structures will work well with Monger.

Current store will strip off namespace information from namespaced keywords because clojure.core/name work that way. For example:

(name ::identity)

Reported by Julio Barros.

Changes between 1.0.0-rc2 and 1.0.0

Extended support for BSON serialization for Joda Time types

monger.joda-time previously only extended BSON (DBObjects) conversion protocol for org.joda.time.DateTime. While DateTime is the most commonly used type in JodaTime, plenty of other types are also used and may need to be stored in MongoDB documents.

Now Monger handles serialization for all JodaTime types that inherit from org.joda.time.base.AbstractInstant, for example, org.joda.time.DateTime and org.joda.time.DateMidnight.

Changes between 1.0.0-rc1 and 1.0.0-rc2

Ragtime integration

Monger now provides an adapter for Ragtime, a generic Clojure library for data migrations (evolutions).

It is in the monger.ragtime namespace. To use Ragtime with Monger, you need to add dependencies on both Ragtime core and Monger to your project. An example with Leiningen:

:dependencies [[org.clojure/clojure       "1.4.0"]
               [com.novemberain/monger    "1.0.0-rc2"]
               [ragtime/ragtime.core      "0.2.0"]]

Then require monger.ragtime and use Ragtime as usual, passing it a database instance you get via monger.core/get-db.

Monger will persist information about migrations using the FSYNC_SAFE write concern.

Query DSL no longer seq()s the cursor

Query DSL will no longer apply clojure.core/seq to the underlying cursor, thus guaranteeing to return an empty sequence when there are no results. This gives developers better control over what do they want to get back: an empty sequence or nil. In the latter case, they will just manually apply clojure.core/seq to the result.

More flexible monger.collection/ensure-index and monger.collection/create-index

monger.collection/ensure-index and monger.collection/ensure-index now accept fields to index as a collection (e.g. a vector) as well as a map. It is convenient when creating multiple single-field indexes at once.

Changes between 1.0.0-beta8 and 1.0.0-rc1

Documentation improvements

Documentation guides have been greatly improved and now include several new guides:


monger.core/current-db returns the currently used database.


monger.core/use-db! composes monger.core/set-db! and monger.core/get-db:

(ns my.service
  (:use [monger.core :only [set-db! use-db! get-db]]))

;; equivalent
(use-db! "my_product")
(set-db! (get-db "my_product"))

monger.result/ok? now works on Clojure maps

monger.result/ok? has been implemented for Clojure maps.

Changes between 1.0.0-beta7 and 1.0.0-beta8

GridFS support improvements

Monger finally has a higher-level DSL for storing files on GridFS

(ns my.service
  (:use [monger.gridfs :only [store-file make-input-file filename content-type metadata]]))

;; store a file from a local FS path with the given filename, content type and metadata
(store-file (make-input-file "/path/to/a/local/file.png")
  (filename "image.png")
  (metadata {:format "png"})
  (content-type "image/png"))

There are also querying improvements: monger.gridfs/find-maps and monger.gridfs/find-one-as-map are new functions that were added. They serve the same purposes as monger.collection/find-maps and monger.collection/find-one-as-map, making it easy to work with Clojure data structures all the time.

monger.gridfs/files-as-maps works the same way as monger.gridfs/all-files but returns results as Clojure maps. It is to monger.gridfs/all-files what monger.collection/find-maps is to monger.collection/find.

MongoDB 2.1/2.2 Aggregation Framework support

monger.collection/aggregate provides a convenient way to run aggregation queries.

(ns my.service
  (:require [monger.collection :as mc])
  (:use monger.operators))

;; single stage pipeline
(mc/aggregate "docs" [{$project {:subtotal {$multiply ["$quantity", "$price"]}
                                                       :_id     "$state"}}])

;; two stage pipeline
(mc/aggregate "docs" [{$project {:subtotal {$multiply ["$quantity", "$price"]}
                                                       :_id      1
                                                       :state   1}}
                                            {$group   {:_id   "$state"
                                                       :total {$sum "$subtotal"}}}])

The following couple of tests demonstrates aggregation queries with some sample data:

(deftest ^{:edge-features true} test-basic-projection-with-multiplication
  (let [collection "docs"
        batch      [{ :state "CA" :quantity 1 :price 199.00 }
                    { :state "NY" :quantity 2 :price 199.00 }
                    { :state "NY" :quantity 1 :price 299.00 }
                    { :state "IL" :quantity 2 :price 11.50  }
                    { :state "CA" :quantity 2 :price 2.95   }
                    { :state "IL" :quantity 3 :price 5.50   }]
        expected    [{:_id "NY" :subtotal 398.0}
                     {:_id "NY" :subtotal 299.0}
                     {:_id "IL" :subtotal 23.0}
                     {:_id "CA" :subtotal 5.9}
                     {:_id "IL" :subtotal 16.5}
                     {:_id "CA" :subtotal 199.0}]]
    (mc/insert-batch collection batch)
    (let [result (vec (mc/aggregate "docs" [{$project {:subtotal {$multiply ["$quantity", "$price"]}
                                                       :_id     "$state"}}]))]
      (is (= expected result)))))

(deftest ^{:edge-features true} test-basic-total-aggregation
  (let [collection "docs"
        batch      [{ :state "CA" :quantity 1 :price 199.00 }
                    { :state "NY" :quantity 2 :price 199.00 }
                    { :state "NY" :quantity 1 :price 299.00 }
                    { :state "IL" :quantity 2 :price 11.50  }
                    { :state "CA" :quantity 2 :price 2.95   }
                    { :state "IL" :quantity 3 :price 5.50   }]
        expected    [{:_id "CA", :total 204.9} {:_id "IL", :total 39.5} {:_id "NY", :total 697.0}]]
    (mc/insert-batch collection batch)
    (let [result (vec (mc/aggregate "docs" [{$project {:subtotal {$multiply ["$quantity", "$price"]}
                                                       :_id      1
                                                       :state   1}}
                                            {$group   {:_id   "$state"
                                                       :total {$sum "$subtotal"}}}]))]
      (is (= expected result)))))

The aggregation framework is an edge feature that will be available in MongoDB 2.2.

More Operators

Two new operator macros: $regex, $options and those used by the upcoming MongoDB 2.2 Aggregation framework.

Changes between 1.0.0-beta6 and 1.0.0-beta7

Replica sets support

Monger can now connect to replica sets using one or more seeds when calling monger.core/connect with a collection of server addresses instead of just a single one:

(ns my.service
  (:use monger.core))

;; Connect to a single MongoDB instance
(connect (server-address "" 27017) (mongo-options))

;; Connect to a replica set
(connect [(server-address "" 27017) (server-address "" 27018)]

monger.core/connect! works exactly the same way.

Contributed by Baishampayan Ghose. implementation

Monger now features a Ring session store implementation. To use it, require monger.ring.session-store and use monger.ring.session-store/monger-store function like so:

(ns my.service
  (:use monger.ring.session-store))

(let [store (monger-store "web_sessions")]

Changes between 1.0.0-beta5 and 1.0.0-beta6

find-and-modify support

monger.collection/find-and-modify function implements atomic Find and Modify command. It is similar to the "regular" update operations but atomically modifies a document (at most one) and returns it.

An example:

(mgcol/find-and-modify "scoreboard" {:name "Sophie Bangs"} {$inc {:level 1}} :return-new true)

Contributed by Baishampayan Ghose.

monger.js is deprecated

monger.js namespace is kept for backwards compatibility but is deprecated in favor of ClojureWerkz Support that now has exactly the same function in To add Support to your project with Leiningen, use

[clojurewerkz/support "0.3.0"]

Validateur 1.1.0

Validateur dependency has been upgraded to 1.1.0.

Changes between 1.0.0-beta4 and 1.0.0-beta5

More Operators

Several new operator macros: $size, $exists, $mod, $type, $not.

Clojure sets now can be serialized

Monger now supports serialization for all classes that implement java.util.Set, including Clojure sets.

Capped collection support

monger.collection/create provides a way to create collections with fine-tuned attributes (for example, capped collections) without having to use Java driver API.

clojure.core.cache integration

monger.cache is a new namespace for various cache implementations that adhere to the clojure.core.cache CacheProtocol protocol and sit on top of MongoDB

Clojure symbols now can be serialized

Monger now supports serialization for all classes that implement clojure.lang.Named, not just keywords.

Improved serialization performance

Thanks to faster paths for serialization of strings and dates (java.util.Date), mean time to insert 100,000 documents went down from about 1.7 seconds to about 0.5 seconds.

Changes between 1.0.0-beta3 and 1.0.0-beta4

Support for URI connections (and thus PaaS provides like Heroku)

monger.core/connect-via-uri! is a new function that combines monger.core/connect!, monger.core/set-db! and monger.core/authenticate and works with string URIs like mongodb://

It can be used to connect with or without authentication, for example:

;; connect without authentication
(monger.core/connect-via-uri! "mongodb://")

;; connect with authentication
(monger.core/connect-via-uri! "mongodb://clojurewerkz/monger!:monger!@")

;; connect using connection URI stored in an env variable, in this case, MONGOHQ_URL
(monger.core/connect-via-uri! (System/genenv "MONGOHQ_URL"))

It is also possible to pass connection options as query parameters:

(monger.core/connect-via-uri! "mongodb://localhost/test?maxPoolSize=128&waitQueueMultiple=5;waitQueueTimeoutMS=150;socketTimeoutMS=5500&autoConnectRetry=true;safe=false&w=1;wtimeout=2500;fsync=true")

Changes between 1.0.0-beta2 and 1.0.0-beta3

Support for field negation in queries

Previously to load only a subset of document fields with Monger, one had to specify them all. Starting with 1.0.0-beta3, Monger supports field negation feature of MongoDB: it is possible to exclude certain fields instead.

To do so, pass a map as field selector, with fields that should be omitted set to 0:

;; will retrieve all fields except body
(monger.collection/find-one-map "documents" {:author "John"} {:body 0})

Validateur 1.1.0-beta1

Validateur dependency has been upgraded to 1.1.0-beta1.

Index Options support for monger.collection/ensure-index and /create-index

monger.collection/ensure-index and /create-index now accept index options as additional argument. Breaking change: 3-arity versions of those functions now become 4-arity versions.

Support serialization of Clojure ratios

Documents that contain Clojure ratios (for example, 26/5) now can be converted to DBObject instances and thus stored. On load, ratios will be presented as doubles: this way we ensure interoperability with other languages and clients.

Factories/fixtures DSL

When working with even moderately complex data sets, fixture data quickly becomes difficult to maintain. Monger 1.0.0-beta3 introduce a new factories DSL that is inspired by (but does not try to copy) Ruby's Factory Girl and similar libraries.

It includes support dynamically evaluated attributes and support for two most common techniques for implementing associations between documents.

Here is what it feels like:

(defaults-for "domains"
  :ipv6-enabled false)

(factory "domains" "clojure"
         :name       ""
         :created-at (-> 2 days ago)
         :embedded   [(embedded-doc "pages" "")
                      (embedded-doc "pages" "")
                      (embedded-doc "pages" "")])

(factory "domains" "elixir"
         :name     ""
         :created-at (fn [] (now))
         :topics     (fn [] ["programming" "erlang" "beam" "ruby"])
         :related    {
                      :terms (fn [] ["erlang" "python" "ruby"])

(factory "pages" ""
         :name "/rationale"
         :domain-id (parent-id "domains" "clojure"))
(factory "pages" ""
         :name "/jvm_hosted")
(factory "pages" ""
         :name "/runtime_polymorphism")
(factory "pages" ""
         :name "/lisp")

(build "domains" "clojure" :created-at (-> 2 weeks ago))
(seed  "pages" "")

Leiningen 2

Monger now uses Leiningen 2.


monger.core/set-connection! allows you to instantiate connection object (com.mongodb.Mongo instances) any way you like and then use it as default Monger connection. MongoDB Java driver provides many ways to instantiate and fine tune connections, this is the easiest way for Monger to support them all.

2-arity for monger.core/connect and monger.core/connect!

monger.core/connect now has 2-arity that accepts com.mongodb.ServerAddresss and com.mongodb.MongoOptions instances and allows you fine tune parameters like socket and connection timeouts, default :w value, connection threads settings and so on.

monger.core/mongo-options and monger.core/server-address are helper functions that instantiate those classes from paramters passed as Clojure maps, for convenience.

Changes between 1.0.0-beta1 and 1.0.0-beta2

3-arity of monger.collection/find-one-as-map now takes a vector of fields

3-arity of monger.collection/find-one-as-map now takes a vector of fields instead of keywordize to better fit a more commonly needed case.

;; 3-arity in 1.0.0-beta1
(monger.collection/find-one-as-map "documents" { :first_name "John" } false)
;; 3-arity in 1.0.0-beta2
(monger.collection/find-one-as-map "documents" { :first_name "John" } [:first_name, :last_name, :age])

If you need to use keywordize, use 4-arity:

(monger.collection/find-one-as-map "documents" { :first_name "John" } [:first_name, :last_name, :age] false)

Query DSL has a way to specify if fields need to be keywordized

It is now possible to opt-out of field keywordization in the query DSL:

(with-collection coll
  (find {})
  (limit 3)
  (sort { :population -1 })
  (keywordize-fields false))

the default value is still true, field names will be converted to keywords.

monger.collection/find-by-id and /find-map-by-id fail fast when id is nil

monger.collection/find-by-id and /find-map-by-id now will throw IllegalArgumentException when id is nil

monger.collection/find-map-by-id no longer ignore fields argument

monger.collection/find-map-by-id no longer ignore fields argument. Contributed by Toby Hede.

Meet monger.db and monger.command

monger.db namespace was added to perform operations like adding users or dropping databases. Several functions from monger.core will eventually be moved there, but not for 1.0.

monger.command namespace includes convenience methods for issuing MongoDB commands.

Both are contributed by Toby Hede.

New convenience functions: monger.collection/update-by-id, /remove-by-id

monger.collection/update-by-id is a new convenience function for updating a single document with given ObjectId. monger.collection/remove-by-id is its counterpart for removing documents.


monger.core/get-db-names returns a set of databases. Contributed by Toby Hede.

Jump to Line
Something went wrong with that request. Please try again.