Dexie.js is a wrapper library for indexedDB - the standard database in the browser. http://dexie.org
Dexie solves three main issues with the native IndexedDB API:
- Ambivalent 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).
<!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.
Dexie has a kick-ass performance. It's bulk methods take advantage of a not well 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.
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.
This sample shows how to use Dexie with ES6 compliant environments and npm module resolution. With ES6, the yield keyword can be used instead of calling .then() on every database operation. The yield keyword and generator functions are already supported today (March 2016) in Chrome, Firefox, Edge and Opera without a transpiler (though this example also uses import statements which still needs transpilation). Dive into this? Read SIMPLIFY WITH YIELD!
import Dexie from 'dexie';
//
// Declare Database
//
let db = new Dexie("FriendDatabase");
db.version(1).stores({ friends: "++id,name,age" });
//
// Have Fun
//
db.transaction('rw', db.friends, function*() {
// Make sure we have something in DB:
if ((yield db.friends.where('name').equals('Josephine').count()) === 0) {
let id = yield db.friends.add({name: "Josephine", age: 21});
alert (`Addded friend with id ${id}`);
}
// Query:
let youngFriends = yield db.friends.where("age").below(25).toArray();
// Show result:
alert ("My young friends: " + JSON.stringify(youngFriends));
}).catch(e => {
alert(e.stack || e);
});NOTE: db.transaction() will treat generator functions (function * ) so that it is possible to use yield for consuming promises. Yield can be used outside transactions as well.
import Dexie from 'dexie';
//
// Declare Database
//
var db = new Dexie("FriendDatabase");
db.version(1).stores({ friends: "++id,name,age" });
db.transaction('rw', db.friends, async() => {
// Make sure we have something in DB:
if ((await db.friends.where('name').equals('Josephine').count()) === 0) {
let id = await db.friends.add({name: "Josephine", age: 21});
alert (`Addded friend with id ${id}`);
}
// Query:
let youngFriends = await db.friends.where("age").below(25).toArray();
// Show result:
alert ("My young friends: " + JSON.stringify(youngFriends));
}).catch(e => {
alert(e.stack || e);
});This sample requires using Dexie v2, npm install dexie@^2.0.0-beta
import Dexie from 'dexie';
interface IFriend {
id?: number;
name?: string;
age?: number;
}
//
// Declare Database
//
class FriendDatabase extends Dexie {
friends: Dexie.Table<IFriend,number>;
constructor() {
super("FriendDatabase");
this.version(1).stores({
friends: "++id,name,age"
});
}
}
var db = new FriendDatabase();
db.transaction('rw', db.friends, async() => {
// Make sure we have something in DB:
if ((await db.friends.where('name').equals('Josephine').count()) === 0) {
let id = await db.friends.add({name: "Josephine", age: 21});
alert (`Addded friend with id ${id}`);
}
// Query:
let youngFriends = await db.friends.where("age").below(25).toArray();
// Show result:
alert ("My young friends: " + JSON.stringify(youngFriends));
}).catch(e => {
alert(e.stack || e);
});https://github.com/dfahlander/Dexie.js/tree/master/samples
http://dexie.org/docs/Questions-and-Answers
npm install dexie@^2.0.0-beta
For those who don't like package managers, here's the download links:
https://unpkg.com/dexie@^2.0.0-beta/dist/dexie.js
https://unpkg.com/dexie@^2.0.0-beta/dist/dexie.js.map
https://unpkg.com/dexie@^2.0.0-beta/dist/dexie.d.ts
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.
npm install
npm run build
npm test
npm run watch