Longo

Class: Collection

Longo. Collection

Collection object. Most collection methods return Longo.Cursor object.
In longo inspite of MongoDB, Cursor object does not have and reference to data.
You need to call Longo.Cursor#done or Longo.Cursor#onValue or Longo.Cursor#assign or Longo.Cursor#promise at the end of method chain.

<private> new Collection(name, option, parent)

Do not call this class with new from application.
use Longo.DB#createCollection or Longo.DB#collection method.

Parameters:
Name Type Argument Default Description
name String <optional>
 'temp'

name of this collection
option Object <optional>

config for capped collection

Properties
Name Type Argument Default Description
capped Boolean <optional>
 false

See Longo.DB#createCollection
size Number <optional>
 1024*1024

See Longo.DB#createCollection
max Number <optional>
 1000

See Longo.DB#createCollection
parent DB

database instance
Source:
Example
  var db = Longo.createDB("test");
  db.createCollection("score");

Extends

Methods

addEventListener(type, listner)

Parameters:
Name Type Description
type String

A string representing the event type to listen for.
listner function

The object that receives a notification when an event of the specified type occurs.
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bind()

Alias for EventEmitter.addEventListener

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copyTo(newCollection, query, done) → {String}

Copies all documents from collection into newCollection.
If newCollection does not exist, MongoDB creates it. Longo.Collection.collectionCallback will be called with the number of documents copied.
If the copy fails, it will be called with the error.

Parameters:
Name Type Argument Default Description
newCollection String

Name of destination Collection.
query Object

The query selection query.
done collectionCallback <optional>
 null

callback for result. See Longo.Collection.collectionCallback
Source:
Returns:

opId

Type
String

count(query) → {Cursor}

Returns the count of documents that would match a Longo.Collection#find query.

Parameters:
Name Type Description
query Object

The query selection query.
Source:
Returns:

cursor Cursor object

Type
Cursor

dataSize() → {Cursor}

Return the size of the collection.

Source:
Returns:

cursor Cursor object

Type
Cursor

dispatchEvent(type, data)

Parameters:
Name Type Description
type String

dusoatch event type
data Object

dispatch parameter
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drop(cb)

Drop collection from database.

Parameters:
Name Type Argument Description
cb function <optional>

callback
Source:
Returns:

promise if cb was null

emit()

Alias for EventEmitter.dispatchEvent

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find(query, projection) → {Cursor}

Selects documents in a collection and returns Cursor object.

Parameters:
Name Type Argument Default Description
query Object <optional>
 {}

Specifies selection query using query operators. To return all documents in a collection, omit this parameter or pass an empty document ({}). Specifies the fields to return using projection operators.
projection Object <optional>

To return all fields in the matching document, omit this parameter.
Source:
Returns:

cursor Cursor object

Type
Cursor

findOne(query, projection) → {Cursor}

Returns one document that satisfies the specified query query. If multiple documents satisfy the query, this method returns the first document according to the natural order which reflects the order of documents on the memory. In capped collections, natural order is the same as insertion order.

Parameters:
Name Type Argument Default Description
query Object <optional>
 {}

Specifies selection query using query operators. To return all documents in a collection, omit this parameter or pass an empty document ({}). Specifies the fields to return using projection operators.
projection Object <optional>

To return all fields in the matching document, omit this parameter.
Source:
Returns:

cursor Cursor object

Type
Cursor

insert(document) → {Cursor}

Inserts a document or documents into a collection. Different from MongoDB, this method does not accept second parameter for option.

Only JSON formattable elements are supported. So function and Regex are not stored in the collection.

Parameters:
Name Type Description
document Object | Array

A document or array of documents to insert into the collection.
Source:
Returns:

cursor Cursor object

Type
Cursor

isCapped() → {Boolean}

Return collection is capped.

Source:
Returns:

isCapped

Type
Boolean

off()

Alias for EventEmitter.removeEventListener

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on()

Alias for EventEmitter.addEventListener

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parsist(func)

Save collection snapshot to LocalStorage.
If dataset in this collection changed, persisted data will be updated.

Parameters:
Name Type Description
func function

your error handler
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parsistOnce(func)

Save collection snapshot to LocalStorage.

Parameters:
Name Type Description
func function

your error handler
Source:
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remove(query, justOne) → {Cursor}

Removes documents from a collection.

Parameters:
Name Type Argument Description
query Object

Specifies deletion query using query operators. To delete all documents in a collection, pass an empty document ({}).
justOne Boolean <optional>

To limit the deletion to just one document, set to true. Omit to use the default value of false and delete all documents matching the deletion query.
Source:
Returns:

cursor Cursor object

Type
Cursor

removeEventListener(type, listner)

Parameters:
Name Type Description
type String

A string representing the event type being removed.
listner function

The listener parameter indicates the EventListener function to be removed.
Inherited From:
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renameCollection(The)

Changes the name of an existing collection This method have side effect

Parameters:
Name Type Description
The String

new name of the collection.
Source:

save(doc) → {Cursor}

Updates an existing document or inserts a new document, depending on its document parameter.

Only JSON formattable elements are supported. So function and Regex are not stored in the collection.

Insert
If the document does not contain an _id field, then the save() method performs an insert().
During the operation, the longo will create an ObjectId and assign it to the _id field.

Upsert
If the document contains an _id field, then the save() method performs an update with upsert, querying by the _id field.
If a document does not exist with the specified _id value, the save() method performs an insert.
If a document exists with the specified _id value,
the save() method performs an update that replaces all fields in the existing document with the fields from the document.

Parameters:
Name Type Description
doc Object

A document to save to the collection.
Source:
Returns:

cursor Cursor object

Type
Cursor

setDefaultErrorHandler(func)

Set your own error handler.
By default, Longo just log when some error happen.

Parameters:
Name Type Description
func function

your error handler
Source:

totalSize() → {Cursor}

Return the total size of the data in the collection. As same as Longo.Collection#dataSize

Source:
Returns:

cursor Cursor object

Type
Cursor

trigger()

Alias for EventEmitter.dispatchEvent

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unbind()

Alias for EventEmitter.removeEventListener

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update(query, update, option) → {Cursor}

Modifies an existing document or documents in a collection.
The method can modify specific fields of existing document or documents or replace an existing document entirely,
depending on the update parameter.
By default, the update() method updates a single document.
Set the Multi Parameter to update all documents that match the query criteria.

Parameters:
Name Type Argument Description
query Object

The selection criteria for the update. Use the same query selectors as used in the find() method.
update Object

The modifications to apply.
option Object <optional>

option.

Properties
Name Type Argument Default Description
upsert Boolean <optional>
 false

If set to true, creates a new document when no document matches the query criteria. which does not insert a new document when no match is found.
multi Boolean <optional>
 false

If set to true, updates multiple documents that meet the query criteria. If set to false, updates one document.
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Returns:

cursor Cursor object

Type
Cursor

Type Definitions

collectionCallback(error, result)

Callback structure for Longo.Collection

Parameters:
Name Type Argument Default Description
error Longo.Error <optional>
 null

null when success
result Array <optional>
 null

null when fail
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