Ultra-fast implementation of reactivity for javascript.
You can currently install the package as a npm package or bower component.
The following command installs cellx as a npm package:
npm install cellx --save
The following command installs cellx as a bower component that can be used in the browser:
bower install cellx --save
cellx supports IE9 and above and all modern browsers.
var user = {
firstName: cellx('Matroskin'),
lastName: cellx('Cat'),
fullName: cellx(function() {
return (this.firstName() + ' ' + this.lastName()).trim();
})
};
user.fullName('subscribe', function() {
console.log('fullName: ' + user.fullName());
});
console.log(user.fullName());
// => 'Matroskin Cat'
user.firstName('Sharik');
user.lastName('Dog');
// => 'fullName: Sharik Dog'
Despite the fact that the two dependencies of the cell fullName
has been changed, event handler worked only once.
Important feature of cellx is that it tries to get rid of unnecessary calls
of the event handlers as well as of unnecessary calls of the dependent cells calculation formulas.
In combination with some special optimizations, this leads to an ideal speed of calculation of
the complex dependencies networks.
One test, which is used for measuring the performance, generates grid with multiply "layers" each of which is composed of 4 cells. Cells are calculated from the previous layer of cells (except the first one, which contains initial values) by the formula A2=B1, B2=A1-C1, C2=B1+D1, D2=C1. After that start time is stored, values of all first layer cells are changed and time needed to update all last layer cells is measured. Test results (in milliseconds) for different number of layers (for Google Chrome 53.0.2785.116 (64-bit)):
Library ↓ \ Number of computed layers → | 10 | 20 | 30 | 50 | 100 | 1000 | 5000 | 25000 |
---|---|---|---|---|---|---|---|---|
cellx | <~1 | <~1 | <~1 | <~1 | <~1 | 4 | 20 | 100 |
VanillaJS (naive) | <~1 | 15 | 1750 | >300000 | >300000 | >300000 | >300000 | >300000 |
Knockout | 10 | 750, increases in subsequent runs | 67250, increases in subsequent runs | >300000 | >300000 | >300000 | >300000 | >300000 |
jin-atom (optimized for long chains) | <~1 (2) | <~1 (3) | <~1 (3) | 2 (4) | 3 (6) | 35 (35) | 610 (200) | 12950 (1050) |
Warp9 | 2 | 3 | 4 | 6 | 10 | 140 | 900, increases in subsequent runs | 4200, increases in subsequent runs |
Reactor.js | <~1 | <~1 | 2 | 3 | 5 | 50 | 230 | >300000 |
Reactive.js | <~1 | <~1 | 2 | 3 | 5 | 140 | RangeError: Maximum call stack size exceeded | RangeError: Maximum call stack size exceeded |
Kefir.js | 25 | 2500 | >300000 | >300000 | >300000 | >300000 | >300000 | >300000 |
MobX | <~1 | <~1 | <~1 | 2 | 3 | 40 | RangeError: Maximum call stack size exceeded | RangeError: Maximum call stack size exceeded |
Matreshka.js | 11 | 1150 | 143000 | >300000 | >300000 | >300000 | >300000 | >300000 |
Test sources can be found in the folder perf.
Density of connections in real applications is usually lower than in the present test, that is,
if a certain delay in the test is visible in 100 calculated cells (25 layers), in a real application,
this delay will either be visible in the greater number of cells, or cells formulas will include
some complex calculations (e.g., computation of one array from other).
Cells can be stored in the variables:
var num = cellx(1);
var plusOne = cellx(function() { return num() + 1; });
console.log(plusOne());
// => 2
or in the callable properties:
function User(name) {
this.name = cellx(name);
this.nameInitial = cellx(function() { return this.name().charAt(0).toUpperCase(); });
}
var user = new User('Matroskin');
console.log(user.nameInitial());
// => 'M'
including in the prototype:
function User(name) {
this.name(name);
}
User.prototype.name = cellx();
User.prototype.friends = cellx(function() { return []; }); // each instance of the user will get its own instance of the array
var user1 = new User('Matroskin');
var user2 = new User('Sharik');
console.log(user1.friends() == user2.friends());
// => false
or in simple properties:
function User(name) {
cellx.define(this, {
name: name,
nameInitial: function() { return this.name.charAt(0).toUpperCase(); }
});
}
var user = new User('Matroskin');
console.log(user.nameInitial);
// => 'M'
Use npm module cellx-decorators.
Use npm module cellx-react.
When you create a cell, you can pass some options:
Additional processing of value during reading:
// array that you can't mess up accidentally, the messed up thing will be a copy
var arr = cellx([1, 2, 3], {
get: function(arr) { return arr.slice(); }
});
console.log(arr()[0]);
// => 1
arr()[0] = 5;
console.log(arr()[0]);
// => 1
Used to create recordable calculated cells:
function User() {
this.firstName = cellx('');
this.lastName = cellx('');
this.fullName = cellx(function() {
return (this.firstName() + ' ' + this.lastName()).trim();
}, {
put: function(name) {
name = name.split(' ');
this.firstName(name[0]);
this.lastName(name[1]);
}
});
}
var user = new User();
user.fullName('Matroskin Cat');
console.log(user.firstName());
// => 'Matroskin'
console.log(user.lastName());
// => 'Cat'
Validates the value during recording and calculating.
Validation during recording into the cell:
var num = cellx(5, {
validate: function(value) {
if (typeof value != 'number') {
throw new TypeError('Oops!');
}
}
});
try {
num('I string');
} catch (err) {
console.log(err.message);
// => 'Oops!'
}
console.log(num());
// => 5
Validation during the calculation of the cell:
var value = cellx(5);
var num = cellx(function() {
return value();
}, {
validate: function(value) {
if (typeof value != 'number') {
throw new TypeError('Oops!');
}
}
});
num('subscribe', function(err) {
console.log(err.message);
});
value('I string');
// => 'Oops!'
console.log(value());
// => 'I string'
console.log(num());
// => 5
Calling the cell method is somewhat unusual — the cell itself is called, the first argument passes the method name,
rest ones — the arguments. In this case, there must be at least one argument, or call of the cell will be counted as its
recording. If the method has no arguments, you need to transfer an additional void 0
with a call or to shorten it
just 0
(see dispose
).
Adds a change listener:
var num = cellx(5);
num('addChangeListener', function(evt) {
console.log(evt);
});
num(10);
// => { oldValue: 5, value: 10 }
Removes previously added change listener.
Adds a error listener:
var value = cellx(1);
var num = cellx(function() { return value(); }, {
validate: function(v) {
if (v > 1) {
throw new TypeError('Oops!');
}
}
});
num('addErrorListener', function(evt) {
console.log(evt.error.message);
});
value(2);
// => 'Oops!'
Removes previously added error listener.
Subscribes to the events change
and error
. First argument comes into handler is an error object, second — an event.
user.fullName('subscribe', function(err, evt) {
if (err) {
//
} else {
//
}
});
Unsubscribes from events change
and error
.
Подписаться на изменение свойства созданного с помощью cellx.define
можно через EventEmitter
:
class User extends cellx.EventEmitter {
constructor(name) {
cellx.define(this, {
name,
nameInitial: function() { return this.name.charAt(0).toUpperCase(); }
});
}
}
let user = new User('Матроскин');
user.on('change:nameInitial', function(evt) {
console.log('nameInitial: ' + evt.value);
});
console.log(user.nameInitial);
// => 'М'
user.name = 'Шарик';
// => 'nameInitial: Ш'
In many reactivity engines calculated cell (atom, observable-property) should be seen as a normal event handler for other cells, that is, for "killing" the cell it is not enough to simply remove all handlers from it and lose the link to it, it is also necessary to decouple it from its dependencies. Calculated cells in cellx constantly monitor the presence of handlers for themselves and all their descendants, and in cases of their (handlers) absence went to the passive updates mode, i.e. unsubscribe themselves from their dependencies and are evaluated immediately upon reading. Thus, to "kill" of the cell you just calculated remove from it all handlers added before and forget the link to it; you do not need to think about the other cells, from which it is calculated or which are calculated from it. After this, garbage collector will clean everything.
You can call the dispose
, just in case:
user.name('dispose', 0);
This will remove all the handlers, not only from the cell itself, but also from all cells calculated from it, and in the absence of links all branch of dependencies will "die".
To minimize redraw of UI cellx may "collapse" several events into one. Link to the previous event is stored in
evt.prev
:
var num = cellx(5);
num('addChangeListener', function(evt) {
console.log(evt);
});
num(10);
num(15);
num(20);
// => {
// oldValue: 15,
// value: 20,
// prev: {
// oldValue: 10,
// value: 15,
// prev: {
// oldValue: 5,
// value: 10,
// prev: null
// }
// }
// }
In cases when the cell comes to the initial value before generation of event, it does not generate it at all:
var num = cellx(5);
num('addChangeListener', function(evt) {
console.log(evt);
});
num(10);
num(15);
num(5); // return the original value
// but there's nothing here
Upon changing the number of the calculated cell dependencies, it is evaluated only once and creates only one event:
var inited = false;
var num1 = cellx(5);
var num2 = cellx(10);
var sum = cellx(function() {
if (inited) {
console.log('sum.formula');
}
return num1() + num2();
});
sum('addChangeListener', function(evt) {
console.log(evt);
});
inited = true;
num1(10);
num2(15);
// => 'sum.formula'
// => {
// oldValue: 15,
// value: 25,
// prev: null
// }
Calculated cell formula can be written so that a set of dependencies may change over time. For example:
var user = {
firstName: cellx(''),
lastName: cellx(''),
name: cellx(function() {
return this.firstName() || this.lastName();
})
};
There, while firstName
is still empty string, cell name
is signed for firstName
and lastName
,
and change in any of them will lead to the change in its value. If you assign to the firstName
some not empty
string, then during recalculation of value name
it simply will not come to reading lastName
in the formula,
i.e. the value of the cell name
from this moment will not depend on lastName
.
In such cases, cells automatically unsubscribe from dependencies insignificant for them and are not recalculated
when they change. In the future, if the firstName
again become an empty string, the cell name
will re-subscribe
to the lastName
.
var foo = cellx(function() {
return localStorage.foo || 'foo';
}, {
put: function(value) {
localStorage.foo = value;
this.push(value);
}
});
var foobar = cellx(function() {
return foo() + 'bar';
});
console.log(foobar()); // => 'foobar'
console.log(localStorage.foo); // => undefined
foo('FOO');
console.log(foobar()); // => 'FOObar'
console.log(localStorage.foo); // => 'FOO'
var request = (function() {
var value = 1;
return {
get: function(url) {
return new Promise(function(resolve, reject) {
setTimeout(function() {
resolve({
ok: true,
value: value
});
}, 1000);
});
},
put: function(url, params) {
return new Promise(function(resolve, reject) {
setTimeout(function() {
value = params.value;
resolve({
ok: true
});
}, 1000);
});
}
};
})();
var foo = cellx(function(push, fail, oldValue) {
request.get('http://...').then(function(res) {
if (res.ok) {
push(res.value);
} else {
fail(res.error);
}
});
return oldValue || 0;
}, {
put: function(value, push, fail, oldValue) {
request.put('http://...', { value: value }).then(function(res) {
if (res.ok) {
push(value);
} else {
fail(res.error);
}
});
}
});
foo('subscribe', function() {
console.log('New foo value: ' + foo());
foo(5);
});
console.log(foo());
// => 0
foo('then', function() {
console.log(foo());
});
// => 'New foo value: 1'
// => 1
// => 'New foo value: 5'
If you record to the cell an instance of class which inherits of cellx.EventEmitter
,
then the cell will subscribe to its change
event and will claim it as own:
var value = cellx(new cellx.EventEmitter());
value('subscribe', function(err, evt) {
console.log(evt.ok);
});
value().emit({ type: 'change', ok: true });
// => true
Due to this, you can create your collections, upon updating those collections you will update the cell containing them and dependent cells will be recalculated. Two such collections already is added to the cellx:
The short syntax to create:
var map = cellx.map({
key1: 1,
key2: 2,
key3: 3
});
cellx.ObservableMap
repeats
Map from ECMAScript 2015,
except for the following differences:
- inherits of
cellx.EventEmitter
and generates an eventchange
when changing their records; - has a method
contains
, which let you know whether or not the value is contained in the map, without going over all of its values; - has a method
clone
, which creates a copy of map; - data on initialization can be not only an array but also in the form of an object (in this case, only strings will be counted as keys, and the key difference between object and Map is in the fact that the keys in the Map can be of any type) or another map.
Short creation syntax:
var list = cellx.list([1, 2, 3]);
Like cellx.ObservableMap
, list generates an event change
upon any change of its records.
During initialization the list may take option comparator
, which will implement the assortment of its values:
var list = cellx.list([
{ x: 5 },
{ x: 1 },
{ x: 10 }
], {
comparator: function(a, b) {
if (a.x < b.x) { return -1; }
if (a.x > b.x) { return 1; }
return 0;
}
});
console.log(list.toArray());
// => [{ x: 1 }, { x: 5 }, { x: 10 }]
list.addRange([{ x: 100 }, { x: -100 }, { x: 7 }]);
console.log(list.toArray());
// => [{ x: -100 }, { x: 1 }, { x: 5 }, { x: 7 }, { x: 10 }, { x: 100 }]
If instead of comparator
you pass the option sorted
with the value true
, it will use the standard comparator
:
var list = cellx.list([5, 1, 10], { sorted: true });
console.log(list.toArray());
// => [1, 5, 10]
list.addRange([100, -100, 7]);
console.log(list.toArray());
// => [-100, 1, 5, 7, 10, 100]
Length of the list. Read-only.
Function for comparing values in the sorted list. Read-only.
Whether or not the list is sorted. Read-only.
Important difference between list and array is that the list can't contain so-called "holes"
that is, when it will try to read or set the value of the index beyond the existing range of elements,
an exception will be generated.
Range extension (adding of items) occurs through methods add
, addRange
, insert
and insertRange
.
In such case, in the last two methods passed index
can not be longer than the length of the list.
Sorted list suggests that its values are always in sorted order. Methods
set
, setRange
, insert
and insertRange
are contrary to this statement, they either will break the correct order
of sorting or (for preservation of this order) will install/paste past the specified index, i.e.
will not work properly. Therefore, when you call the sorted list, they always generate an exception. It is possible to
add values to the sorted list through the methods add
and addRange
, or during initialization of the list.
Type signature: (value) -> boolean;
.
Checks if the value is in the list. In cases of a large amount of values in the list it may be significantly faster
than list.indexOf(value) != -1
.
Type signature: (value, fromIndex?: int) -> int;
.
Type signature: (value, fromIndex?: int) -> int;
.
Type signature: (index: int) -> *;
.
Type signature: (index: int, count?: uint) -> Array;
.
If count
is unspecified it makes copies till the end of the list.
Type signature: (index: int, value) -> cellx.ObservableList;
.
Type signature: (index: int, values: Array) -> cellx.ObservableList;
.
Type signature: (value) -> cellx.ObservableList;
.
Type signature: (values: Array) -> cellx.ObservableList;
.
Type signature: (index: int, value) -> cellx.ObservableList;
.
Type signature: (index: int, values: Array) -> cellx.ObservableList;
.
Type signature: (value, fromIndex?: int) -> boolean;
.
Removes the first occurrence of value
in the list.
Type signature: (value, fromIndex?: int) -> boolean;
.
It removes all occurrences of value
list.
Type signature: (values: Array, fromIndex?: int) -> boolean;
.
Type signature: (values: Array, fromIndex?: int) -> boolean;
.
Type signature: (index: int) -> *;
.
Type signature: (index: int, count?: uint) -> Array;
.
If count
is unspecified it will remove everything till the end of the list.
Type signature: () -> cellx.ObservableList;
.
Type signature: (separator?: string) -> string;
.
Type signature: (cb: (item, index: uint, list: cellx.ObservableList), context?);
.
Type signature: (cb: (item, index: uint, list: cellx.ObservableList) -> *, context?) -> Array;
.
Type signature: (cb: (item, index: uint, list: cellx.ObservableList) -> ?boolean, context?) -> Array;
.
Type signature: (cb: (item, index: uint, list: cellx.ObservableList) -> ?boolean, context?) -> *;
.
Type signature: (cb: (item, index: uint, list: cellx.ObservableList) -> ?boolean, context?) -> int;
.
Type signature: (cb: (item, index: uint, list: cellx.ObservableList) -> ?boolean, context?) -> boolean;
.
Type signature: (cb: (item, index: uint, list: cellx.ObservableList) -> ?boolean, context?) -> boolean;
.
Type signature: (cb: (accumulator, item, index: uint, list: cellx.ObservableList) -> *, initialValue?) -> *;
.
Type signature: (cb: (accumulator, item, index: uint, list: cellx.ObservableList) -> *, initialValue?) -> *;
.
Type signature: () -> cellx.ObservableList;
.
Type signature: () -> Array;
.
Type signature: () -> string;
.
File | Original | Gzipped |
---|---|---|
cellx.js | 58.78 kB | 11.58 kB |
cellx.min.js | 24.96 kB | 7.1 kB |