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Storage

Storage and Storage.Index classes provide built-in data persistence - transparent data storage and retrieval using just JavaScript means.

Introduction and usage manual.

Architecture explained.

class Storage

Represents persistent storage.

Properties​

root​

object, root object in the storage. Read/write property.

Methods​

open​

Storage.open(filepath : string [,allowWrite: true [, password: string ]] ) : storage | null

Static method. Opens storage and returns an instance of Storage object.

Parameters:

  • filepath - string, required. Absolute path in local filesystem of the DB file.
  • allowWrite - boolean, optional. If it is false then storage is opened in read-only mode.
  • password - string, optional. If password is provided then the function creates and opens file in encrypted mode.

close​

storage.close()

Closes underlying Storage. Commits all data before closing. After closing the storage all persistent objects that are still in use are set to non-persistent state.

commit​

storage.commit()

Commits (writes) all persistent objects reachable from its root into storage. Does not close the storage.

tip

Use this method after complex or critical data modifications.

createIndex​

storage.createIndex(type : string [, unique: bool]) returns: Index | null

Creates an index of given type and returns the index object. Index can have unique or duplicated keys depending on unique argument.

parameters:

  • type, string, one of:
    • "integer" - int32 keys
    • "long" - int64 keys
    • "float"
    • "date"
    • "string"
  • unique, boolean, if true then the index supports only unique keys. Default value for is true.

registerClass​

storage.registerClass(cls)

Registers class (a.k.a. constructor function in terms of ES5) of persistable objects.

When an object is stored into DB, name of its class is also stored. When the object is fetched from the DB, it gets the class assigned automatically if that class was registered before.