mapreduce - Documentation

cozysdk Map Reduce functions

Queries in cozy are made using couchdb map/reduce view system. Read more in the tutorial.

Tutorials:

Map Reduce Queries

Methods

(static) defineView(docType, name, request, callbackopt)

Define a map/reduce request for a given doc type.

Parameters:

Name	Type	Attributes	Description
`docType`	string		The doctype you want to create a view on.
`name`	string		The name of the view to create.
`request`	string \| function \| object		The request to define. it can either be a function, a string (function.toString()) or an object with map & reduce attributes.
`callback`	callback	<optional>	A node.js style callback

Examples

callback

byTitle = function(doc) { emit(doc.title); }
cozysdk.defineView('Note', 'all', byTitle, function(err){
    // view has been created
});

promise

byTitle = function(doc) { emit(doc.title); }
cozysdk.defineView('Note', 'all', byTitle)

(static) destroyByView(docType, name, params, callbackopt)

Destroy every documents that would have been returned by a call to queryView with the same parameters. Destroy all DocumentsQuery a map/reduce view. It accepts CouchDB like params.

Parameters:

Name Type Attributes Description

docType string The doctype you want to query a view on.

name string The name of the view to query.

params

object

The same query parameters than queryView.

Properties

Name	Type	Description
`limit`	object	Warning The limit param is ignored for deletion.

callback callback <optional> A node.js style callback

Examples

callback

params = {startkey 'A', endkey: 'B'}
cozysdk.destroyByView('Note', 'byTitle', params, function(err){
    // destroy all notes with a title starting by A
});

promise

params = {startkey 'A', endkey: 'B'}
cozysdk.destroyByView('Note', 'byTitle', params)

(static) queryView(docType, name, params, callbackopt)

Query a map/reduce view. It accepts CouchDB like params.

Parameters:

Name Type Attributes Description

docType string The doctype you want to query a view on.

name string The name of the view to query.

params

object

The query parameters.

Properties

Name	Type	Attributes	Default	Description
`key`	mixed	<optional>		Get all entries with this key
`keys`	Array.<mixed>	<optional>		Get all entries with one of these keys
`startkey`	mixed	<optional>		Get all entries with key greater than this value
`startkey_docid`	string	<optional>		Document id to start with (to allow pagination for duplicate startkeys)
`endkey`	mixed	<optional>		Get all entries with key lesser than this value
`endkey_docid`	string	<optional>		Last document id to include in the output (to allow pagination for duplicate endkeys)
`limit`	number	<optional>	Infinity	Limit the number of documents in the output
`skip`	number	<optional>	0	Skip n number of documents
`descending`	boolean	<optional>	false	Change the direction of search
`group`	boolean	<optional>	false	The group option controls whether the reduce function reduces to a set of distinct keys or to a single result row.
`group_level`	number	<optional>		See below
`reduce`	boolean	<optional>	true	Use the reduce function of the view. It defaults to true, if a reduce function is defined and to false otherwise.
`include_docs`	boolean	<optional>	false	Automatically fetch and include the document which emitted each view entry
`inclusive_end`	boolean	<optional>	true	Controls whether the endkey is included in the result. It defaults to true.
`update_seq=`	boolean	<optional>		Response includes an update_seq value indicating which sequence id of the database the view reflects

callback callback <optional> A node.js style callback

Examples

callback

params = {startkey 'A', endkey: 'B'}
cozysdk.queryView('Note', 'byTitle', params, function(err){
    // get all notes with a title starting by A
});

promise

params = {startkey 'A', endkey: 'B'}
cozysdk.queryView('Note', 'byTitle', params)