const EventEmitter = require ( 'events' )
module . exports = class IndexDbController extends EventEmitter {
constructor ( opts ) {
super ( )
this . migrations = opts . migrations
this . key = opts . key
this . dbObject = global . indexedDB
this . IDBTransaction = global . IDBTransaction || global . webkitIDBTransaction || global . msIDBTransaction || { READ _WRITE : "readwrite" } ; // This line should only be needed if it is needed to support the object's constants for older browsers
this . IDBKeyRange = global . IDBKeyRange || global . webkitIDBKeyRange || global . msIDBKeyRange ;
this . version = opts . version
this . logging = opts . logging
this . initialState = opts . initialState
if ( this . logging ) this . on ( 'log' , logger )
}
// Opens the database connection and returns a promise
open ( version = this . version ) {
return new Promise ( ( resolve , reject ) => {
const dbOpenRequest = this . dbObject . open ( this . key , version )
dbOpenRequest . onerror = ( event ) => {
return reject ( event )
}
dbOpenRequest . onsuccess = ( event ) => {
this . db = dbOpenRequest . result
if ( ! this . db . objectStoreNames . length ) {
Object . keys ( this . initialState ) . forEach ( ( key ) => {
this . _add ( key , this . initialState [ key ] )
} )
}
this . emit ( 'success' )
resolve ( this . db )
}
dbOpenRequest . onupgradeneeded = ( event ) => {
// if (this.migrators)
this . db = event . target . result
this . migrate ( )
}
} )
}
requestObjectStore ( key , type = 'readonly' ) {
return new Promise ( ( resolve , reject ) => {
const dbReadWrite = this . db . transaction ( key , type )
const dataStore = dbReadWrite . objectStore ( key )
resolve ( dataStore )
} )
}
get ( key ) {
return this . requestObjectStore ( key )
. then ( ( dataObject ) => {
return new Promise ( ( resolve , reject ) => {
const getRequest = dataObject . get ( key )
getRequest . onsuccess = ( event ) => resolve ( event . currentTarget . result )
getRequest . onerror = ( event ) => reject ( event )
} )
} )
}
put ( key , store ) {
return this . requestObjectStore ( key , 'readwrite' )
. then ( ( dataObject ) => {
const putRequest = dataObject . put ( store )
putRequest . onsuccess = ( event ) => Promise . resolve ( event . currentTarget . result )
putRequest . onerror = ( event ) => Promise . reject ( event )
} )
}
update ( key , value ) {
}
migrate ( ) {
this . db . createObjectStore ( this . name )
}
_add ( key , objStore , cb = logger ) {
return this . requestObjectStore ( key , 'readwrite' )
. then ( ( dataObject ) => {
const addRequest = dataObject . add ( objStore , key )
addRequest . onsuccess = ( event ) => Promise . resolve ( event . currentTarget . result )
addRequest . onerror = ( event ) => Promise . reject ( event )
} )
}
}
function logger ( err , ress ) {
err ? console . error ( ` Logger says: ${ err } ` ) : console . dir ( ` Logger says: ${ ress } ` )
}