Notes2/static/js/node_store.mjs
Magnus Åhall 42b66714aa wip
2024-12-02 15:26:35 +01:00

119 lines
3.1 KiB
JavaScript

import { API } from 'api'
export class NodeStore {
constructor() {//{{{
if (!('indexedDB' in window)) {
throw 'Missing IndexedDB'
}
this.db = null
}//}}}
async initializeDB() {//{{{
return new Promise((resolve, reject) => {
const req = indexedDB.open('notes', 2)
// Schema upgrades for IndexedDB.
// These can start from different points depending on updates to Notes2 since a device was online.
req.onupgradeneeded = (event) => {
let store
const db = event.target.result
const trx = event.target.transaction
for (let i = event.oldVersion + 1; i <= event.newVersion; i++) {
console.log(`Upgrade to schema ${i}`)
// The schema transformations.
switch (i) {
case 1:
store = db.createObjectStore('nodes', { keyPath: 'ID' })
store.createIndex('nameIndex', 'Name', { unique: false })
break
case 2:
trx.objectStore('nodes').createIndex('parentIndex', 'ParentID', { unique: false })
break
}
}
}
req.onsuccess = (event) => {
this.db = event.target.result
resolve()
}
req.onerror = (event) => {
reject(event.target.error)
}
})
}//}}}
async add(records) {//{{{
return new Promise((resolve, reject) => {
try {
const t = this.db.transaction('nodes', 'readwrite')
const nodeStore = t.objectStore('nodes')
t.onerror = (event) => {
console.log('transaction error', event.target.error)
reject(event.target.error)
}
t.oncomplete = () => {
resolve()
}
for (const record in records) {
const addReq = nodeStore.put(record)
addReq.onsuccess = () => {
console.log('OK!', record.ID, record.Name)
}
addReq.onerror = (event) => {
console.log('Error!', event.target.error, record.ID)
}
}
} catch (e) {
console.log(e)
}
})
}//}}}
async get(id) {//{{{
return new Promise((resolve, reject) => {
// Node is always returned from IndexedDB if existing there.
// Otherwise an attempt to get it from backend is executed.
const trx = this.db.transaction('nodes', 'readonly')
const nodeStore = trx.objectStore('nodes')
const getRequest = nodeStore.get(id)
getRequest.onsuccess = (event) => {
// Node found in IndexedDB and returned.
if (event.target.result !== undefined) {
resolve(event.target.result)
return
}
// Node not found and a request to the backend is made.
API.query("POST", `/node/retrieve/${id}`, {})
.then(res => {
const trx = this.db.transaction('nodes', 'readwrite')
const nodeStore = trx.objectStore('nodes')
const putRequest = nodeStore.put(res.Node)
putRequest.onsuccess = () => resolve(res.Node)
putRequest.onerror = (event) => {
reject(event.target.error)
}
})
.catch(e => reject(e))
}
})
}//}}}
async getTreeNodes() {//{{{
return new Promise((resolve, reject) => {
const trx = this.db.transaction('nodes', 'readonly')
const nodeStore = trx.objectStore('nodes')
const req = nodeStore.getAll()
req.onsuccess = (event) => resolve(event.target.result)
req.onerror = (event) => reject(event.target.error)
})
}//}}}
}
// vim: foldmethod=marker