Dexie.js
Dexie.js is a wrapper library for indexedDB - the standard database in the browser. https://dexie.org
Why?
Dexie solves three main issues with the native IndexedDB API:
- Ambiguous error handling
- Poor queries
- Code complexity
Dexie provides a neat database API with a well thought-through API design, robust error handling, extendability, change tracking awareness and extended KeyRange support (case insensitive search, set matches and OR operations).
Hello World
<!doctype html>
<html>
<head>
<script src="https://unpkg.com/dexie@latest/dist/dexie.js"></script>
<script>
//
// Declare Database
//
var db = new Dexie("FriendDatabase");
db.version(1).stores({
friends: "++id,name,age"
});
//
// Manipulate and Query Database
//
db.friends.add({name: "Josephine", age: 21}).then(function() {
return db.friends.where("age").below(25).toArray();
}).then(function (youngFriends) {
alert ("My young friends: " + JSON.stringify(youngFriends));
}).catch(function (e) {
alert ("Error: " + (e.stack || e));
});
</script>
</head>
</html>Yes, it's that simple.
An equivalent modern version (works in all modern browsers):
<!doctype html>
<html>
<head>
<script type="module">
import Dexie from "https://unpkg.com/dexie@latest/dist/modern/dexie.mjs";
//
// Declare Database
//
const db = new Dexie("FriendDatabase");
db.version(1).stores({
friends: "++id,name,age"
});
//
// Manipulate and Query Database
//
try {
await db.friends.add({name: "Josephine", age: 21});
const youngFriends = await db.friends.where("age").below(25).toArray();
alert (`My young friends: ${JSON.stringify(youngFriends)}`);
} catch (e) {
alert (`Error: ${e}`);
}
</script>
</head>
</html>Performance
Dexie has kick-ass performance. Its bulk methods take advantage of a lesser-known feature in IndexedDB that makes it possible to store stuff without listening to every onsuccess event. This speeds up the performance to a maximum.
Supported operations
above(key): Collection;
aboveOrEqual(key): Collection;
add(item, key?): Promise;
and(filter: (x) => boolean): Collection;
anyOf(keys[]): Collection;
anyOfIgnoreCase(keys: string[]): Collection;
below(key): Collection;
belowOrEqual(key): Collection;
between(lower, upper, includeLower?, includeUpper?): Collection;
bulkAdd(items: Array): Promise;
bulkDelete(keys: Array): Promise;
bulkPut(items: Array): Promise;
clear(): Promise;
count(): Promise;
delete(key): Promise;
distinct(): Collection;
each(callback: (obj) => any): Promise;
eachKey(callback: (key) => any): Promise;
eachPrimaryKey(callback: (key) => any): Promise;
eachUniqueKey(callback: (key) => any): Promise;
equals(key): Collection;
equalsIgnoreCase(key): Collection;
filter(fn: (obj) => boolean): Collection;
first(): Promise;
get(key): Promise;
inAnyRange(ranges): Collection;
keys(): Promise;
last(): Promise;
limit(n: number): Collection;
modify(changeCallback: (obj: T, ctx:{value: T}) => void): Promise;
modify(changes: { [keyPath: string]: any } ): Promise;
noneOf(keys: Array): Collection;
notEqual(key): Collection;
offset(n: number): Collection;
or(indexOrPrimayKey: string): WhereClause;
orderBy(index: string): Collection;
primaryKeys(): Promise;
put(item: T, key?: Key): Promise;
reverse(): Collection;
sortBy(keyPath: string): Promise;
startsWith(key: string): Collection;
startsWithAnyOf(prefixes: string[]): Collection;
startsWithAnyOfIgnoreCase(prefixes: string[]): Collection;
startsWithIgnoreCase(key: string): Collection;
toArray(): Promise;
toCollection(): Collection;
uniqueKeys(): Promise;
until(filter: (value) => boolean, includeStopEntry?: boolean): Collection;
update(key: Key, changes: { [keyPath: string]: any }): Promise;This is a mix of methods from WhereClause, Table and Collection. Dive into the API reference to see the details.
Hello World (Typescript)
import Dexie, { Table } from 'dexie';
interface Friend {
id?: number;
name?: string;
age?: number;
}
//
// Declare Database
//
class FriendDatabase extends Dexie {
public friends!: Table<Friend, number>; // id is number in this case
public constructor() {
super("FriendDatabase");
this.version(1).stores({
friends: "++id,name,age"
});
}
}
const db = new FriendDatabase();
db.transaction('rw', db.friends, async() => {
// Make sure we have something in DB:
if ((await db.friends.where({name: 'Josephine'}).count()) === 0) {
const id = await db.friends.add({name: "Josephine", age: 21});
alert (`Addded friend with id ${id}`);
}
// Query:
const youngFriends = await db.friends.where("age").below(25).toArray();
// Show result:
alert ("My young friends: " + JSON.stringify(youngFriends));
}).catch(e => {
alert(e.stack || e);
});Samples
https://dexie.org/docs/Samples
https://github.com/dfahlander/Dexie.js/tree/master/samples
Knowledge Base
https://dexie.org/docs/Questions-and-Answers
Website
Install over npm
npm install dexie
Download
For those who don't like package managers, here's the download links:
Legacy:
https://unpkg.com/dexie@latest/dist/dexie.min.js
https://unpkg.com/dexie@latest/dist/dexie.min.js.map
Modern:
https://unpkg.com/dexie@latest/dist/modern/dexie.min.mjs
https://unpkg.com/dexie@latest/dist/modern/dexie.min.mjs.map
Typings:
https://unpkg.com/dexie@latest/dist/dexie.d.ts
Contributing
Here is a little cheat-sheet for how to symlink your app's node_modules/dexie to a place where you can edit the source, version control your changes and create pull requests back to Dexie. Assuming you've already ran npm install dexie --save for the app your are developing.
-
Fork Dexie.js from the web gui on github
-
Clone your fork locally by launching a shell/command window and cd to a neutral place (like
~repos/,c:\reposor whatever) -
Run the following commands:
git clone https://github.com/YOUR-USERNAME/Dexie.js.git dexie cd dexie npm install npm run build npm link -
cd to your app directory and write:
npm link dexie
Your app's node_modules/dexie/ is now sym-linked to the Dexie.js clone on your hard drive so any change you do there will propagate to your app. Build dexie.js using npm run build or npm run watch. The latter will react on any source file change and rebuild the dist files.
That's it. Now you're up and running to test and commit changes to files under dexie/src/* or dexie/test/* and the changes will instantly affect the app you are developing.
Pull requests are more than welcome. Some advices are:
- Run npm test before making a pull request.
- If you find an issue, a unit test that reproduces it is lovely ;). If you don't know where to put it, put it in
test/tests-misc.js. We use qunit. Just look at existing tests intests-misc.jsto see how they should be written. Tests are transpiled in the build script so you can use ES6 if you like.
Build
npm install
npm run build
Test
npm test
Watch
npm run watch