Files
owl/src/component/component.ts
T
2019-10-28 11:32:43 +01:00

664 lines
20 KiB
TypeScript

import { Observer } from "../core/observer";
import { CompiledTemplate, QWeb } from "../qweb/index";
import { h, patch, VNode } from "../vdom/index";
import "./directive";
import { Fiber } from "./fiber";
import "./props_validation";
import { Scheduler } from "./scheduler";
/**
* Owl Component System
*
* This file introduces a declarative and composable component system. It
* contains:
*
* - the Env interface (generic type for the environment)
* - the Internal interface (the owl specific metadata attached to a component)
* - the Component class
*/
//------------------------------------------------------------------------------
// Types/helpers
//------------------------------------------------------------------------------
const raf = window.requestAnimationFrame.bind(window);
export const scheduler = new Scheduler(raf);
/**
* An Env (environment) is an object that will be (mostly) shared between all
* components of an Owl application. It is the location which should contain
* the qweb instance necessary to render all components.
*
* Note that it is totally fine to extend the environment with application
* specific keys/objects/whatever. For example, a key `isMobile` (to declare
* if we are in "mobile" mode), or a shared bus could be useful.
*/
export interface Env {
qweb: QWeb;
[key: string]: any;
}
/**
* This is mostly an internal detail of implementation. The Meta interface is
* useful to typecheck and describe the internal keys used by Owl to manage the
* component tree.
*/
interface Internal<T extends Env, Props> {
// each component has a unique id, useful mostly to handle parent/child
// relationships
readonly id: number;
vnode: VNode | null;
pvnode: VNode | null;
isMounted: boolean;
isDestroyed: boolean;
// parent and children keys are obviously useful to setup the parent-children
// relationship.
parent: Component<T, any> | null;
children: { [key: number]: Component<T, any> };
// children mapping: from templateID to componentID. templateID identifies a
// place in a template. The t-component directive needs it to be able to get
// the component instance back whenever the template is rerendered.
cmap: { [key: number]: number };
currentFiber: Fiber | null;
boundHandlers: { [key: number]: any };
observer: Observer | null;
renderFn: CompiledTemplate;
mountedCB: Function | null;
willUnmountCB: Function | null;
willPatchCB: Function | null;
patchedCB: Function | null;
willStartCB: Function | null;
willUpdatePropsCB: Function | null;
classObj: { [key: string]: boolean } | null;
refs: { [key: string]: Component<T, any> | HTMLElement | undefined } | null;
}
//------------------------------------------------------------------------------
// Component
//------------------------------------------------------------------------------
let nextId = 1;
export class Component<T extends Env, Props extends {}> {
readonly __owl__: Internal<Env, Props>;
static template?: string | null = null;
static _template?: string | null = null;
static current: Component<any, any> | null = null;
static components = {};
static props?: any;
static defaultProps?: any;
/**
* The `el` is the root element of the component. Note that it could be null:
* this is the case if the component is not mounted yet, or is destroyed.
*/
get el(): HTMLElement | null {
return this.__owl__.vnode ? (<any>this).__owl__.vnode.elm : null;
}
env: T;
props: Props;
//--------------------------------------------------------------------------
// Lifecycle
//--------------------------------------------------------------------------
/**
* Creates an instance of Component.
*
* The root component of a component tree needs an environment:
*
* ```javascript
* const root = new RootComponent(env, props);
* ```
*
* Every other component simply needs a reference to its parent:
*
* ```javascript
* const child = new SomeComponent(parent, props);
* ```
*
* Note that most of the time, only the root component needs to be created by
* hand. Other components should be created automatically by the framework (with
* the t-component directive in a template)
*/
constructor(parent: Component<T, any> | T, props?: Props) {
const defaultProps = (<any>this.constructor).defaultProps;
Component.current = this;
if (defaultProps) {
props = this.__applyDefaultProps(props, defaultProps);
}
// is this a good idea?
// Pro: if props is empty, we can create easily a component
// Con: this is not really safe
// Pro: but creating component (by a template) is always unsafe anyway
this.props = <Props>props || <Props>{};
let id: number = nextId++;
let p: Component<T, any> | null = null;
if (parent instanceof Component) {
p = parent;
this.env = parent.env;
parent.__owl__.children[id] = this;
} else {
this.env = parent;
if (QWeb.dev) {
// we only validate props for root widgets here. "Regular" widget
// props are validated by the t-component directive
QWeb.utils.validateProps(this.constructor, this.props);
}
this.env.qweb.on("update", this, () => {
if (this.__owl__.isMounted) {
this.render(true);
}
if (this.__owl__.isDestroyed) {
// this is unlikely to happen, but if a root widget is destroyed,
// we want to remove our subscription. The usual way to do that
// would be to perform some check in the destroy method, but since
// it is very performance sensitive, and since this is a rare event,
// we simply do it lazily
this.env.qweb.off("update", this);
}
});
}
const qweb = this.env.qweb;
this.__owl__ = {
id: id,
vnode: null,
pvnode: null,
isMounted: false,
isDestroyed: false,
parent: p,
children: {},
cmap: {},
currentFiber: null,
boundHandlers: {},
mountedCB: null,
willUnmountCB: null,
willPatchCB: null,
patchedCB: null,
willStartCB: null,
willUpdatePropsCB: null,
observer: null,
renderFn: qweb.render.bind(qweb, this.__getTemplate(qweb)),
classObj: null,
refs: null
};
}
/**
* willStart is an asynchronous hook that can be implemented to perform some
* action before the initial rendering of a component.
*
* It will be called exactly once before the initial rendering. It is useful
* in some cases, for example, to load external assets (such as a JS library)
* before the component is rendered.
*
* Note that a slow willStart method will slow down the rendering of the user
* interface. Therefore, some effort should be made to make this method as
* fast as possible.
*
* Note: this method should not be called manually.
*/
async willStart() {}
/**
* mounted is a hook that is called each time a component is attached to the
* DOM. This is a good place to add some listeners, or to interact with the
* DOM, if the component needs to perform some measure for example.
*
* Note: this method should not be called manually.
*
* @see willUnmount
*/
mounted() {}
/**
* The willUpdateProps is an asynchronous hook, called just before new props
* are set. This is useful if the component needs some asynchronous task
* performed, depending on the props (for example, assuming that the props are
* some record Id, fetching the record data).
*
* This hook is not called during the first render (but willStart is called
* and performs a similar job).
*/
async willUpdateProps(nextProps: Props) {}
/**
* The willPatch hook is called just before the DOM patching process starts.
* It is not called on the initial render. This is useful to get some
* information which are in the DOM. For example, the current position of the
* scrollbar
*/
willPatch(): any {}
/**
* This hook is called whenever a component did actually update its props,
* state or env.
*
* This method is not called on the initial render. It is useful to interact
* with the DOM (for example, through an external library) whenever the
* component was updated.
*
* Updating the component state in this hook is possible, but not encouraged.
* One need to be careful, because updates here will cause rerender, which in
* turn will cause other calls to updated. So, we need to be particularly
* careful at avoiding endless cycles.
*/
patched() {}
/**
* willUnmount is a hook that is called each time just before a component is
* unmounted from the DOM. This is a good place to remove some listeners, for
* example.
*
* Note: this method should not be called manually.
*
* @see mounted
*/
willUnmount() {}
/**
* catchError is a method called whenever some error happens in the rendering or
* lifecycle hooks of a child.
*
* It needs to be implemented by a component that is designed to handle the
* error properly.
*/
catchError?(error?: Error): void;
//--------------------------------------------------------------------------
// Public
//--------------------------------------------------------------------------
/**
* Mount the component to a target element.
*
* This should only be done if the component was created manually. Components
* created declaratively in templates are managed by the Owl system.
*
* Note that a component can be mounted an unmounted several times
*/
async mount(target: HTMLElement, renderBeforeRemount: boolean = false): Promise<void> {
const __owl__ = this.__owl__;
if (__owl__.isMounted) {
return Promise.resolve();
}
if (__owl__.vnode && !renderBeforeRemount) {
target.appendChild(this.el!);
if (document.body.contains(target)) {
this.__callMounted();
}
return;
}
const fiber = new Fiber(null, this, this.props, undefined, undefined, false);
if (!__owl__.vnode) {
this.__prepareAndRender(fiber);
} else {
this.__render(fiber);
}
return new Promise((resolve, reject) => {
scheduler.addFiber(fiber, err => {
if (err) {
reject(err);
return;
}
if (!__owl__.isDestroyed) {
this.__patch(fiber.vnode);
target.appendChild(this.el!);
if (document.body.contains(target)) {
this.__callMounted();
}
}
resolve();
});
});
}
/**
* The unmount method is the opposite of the mount method. It is useful
* to call willUnmount calls and remove the component from the DOM.
*/
unmount() {
if (this.__owl__.isMounted) {
this.__callWillUnmount();
this.el!.remove();
}
}
/**
* The render method is the main entry point to render a component (once it
* is ready. This method is not initially called when the component is
* rendered the first time).
*
* This method will cause all its sub components to potentially rerender
* themselves. Note that `render` is not called if a component is updated via
* its props.
*/
async render(force: boolean = false): Promise<void> {
const __owl__ = this.__owl__;
if (
(!__owl__.isMounted && !__owl__.currentFiber) ||
(__owl__.currentFiber && !__owl__.currentFiber.isRendered)
) {
return;
}
const fiber = new Fiber(null, this, this.props, undefined, undefined, force);
this.__render(fiber);
return new Promise((resolve, reject) => {
scheduler.addFiber(fiber.root, err => {
if (err) {
reject(err);
return;
}
if (__owl__.isMounted && fiber === fiber.root) {
fiber.patchComponents();
}
resolve();
});
});
}
/**
* Destroy the component. This operation is quite complex:
* - it recursively destroy all children
* - call the willUnmount hooks if necessary
* - remove the dom node from the dom
*
* This should only be called manually if you created the component. Most
* components will be automatically destroyed.
*/
destroy() {
const __owl__ = this.__owl__;
if (!__owl__.isDestroyed) {
const el = this.el;
this.__destroy(__owl__.parent);
if (el) {
el.remove();
}
}
}
/**
* This method is called by the component system whenever its props are
* updated. If it returns true, then the component will be rendered.
* Otherwise, it will skip the rendering (also, its props will not be updated)
*/
shouldUpdate(nextProps: Props): boolean {
return true;
}
/**
* Emit a custom event of type 'eventType' with the given 'payload' on the
* component's el, if it exists. However, note that the event will only bubble
* up to the parent DOM nodes. Thus, it must be called between mounted() and
* willUnmount().
*/
trigger(eventType: string, payload?: any) {
if (this.el) {
const ev = new CustomEvent(eventType, {
bubbles: true,
cancelable: true,
detail: payload
});
this.el.dispatchEvent(ev);
}
}
//--------------------------------------------------------------------------
// Private
//--------------------------------------------------------------------------
/**
* Private helper to perform a full destroy, from the point of view of an Owl
* component. It does not remove the el (this is done only once on the top
* level destroyed component, for performance reasons).
*
* The job of this method is mostly to call willUnmount hooks, and to perform
* all necessary internal cleanup.
*
* Note that it does not call the __callWillUnmount method to avoid visiting
* all children many times.
*/
__destroy(parent: Component<any, any> | null) {
const __owl__ = this.__owl__;
const isMounted = __owl__.isMounted;
if (isMounted) {
if (__owl__.willUnmountCB) {
__owl__.willUnmountCB();
}
this.willUnmount();
__owl__.isMounted = false;
}
const children = __owl__.children;
for (let key in children) {
children[key].__destroy(this);
}
if (parent) {
let id = __owl__.id;
delete parent.__owl__.children[id];
__owl__.parent = null;
}
__owl__.isDestroyed = true;
delete __owl__.vnode;
}
__callMounted() {
const __owl__ = this.__owl__;
const children = __owl__.children;
for (let id in children) {
const comp = children[id];
if (!comp.__owl__.isMounted && this.el!.contains(comp.el)) {
comp.__callMounted();
}
}
__owl__.isMounted = true;
try {
this.mounted();
if (__owl__.mountedCB) {
__owl__.mountedCB();
}
} catch (e) {
console.error(e); // TODO : add a test
}
}
__callWillUnmount() {
const __owl__ = this.__owl__;
if (__owl__.willUnmountCB) {
__owl__.willUnmountCB();
}
this.willUnmount();
__owl__.isMounted = false;
const children = __owl__.children;
for (let id in children) {
const comp = children[id];
if (comp.__owl__.isMounted) {
comp.__callWillUnmount();
}
}
}
/**
* The __updateProps method is called by the t-component directive whenever
* it updates a component (so, when the parent template is rerendered).
*/
async __updateProps(
nextProps: Props,
parentFiber: Fiber,
scope: any,
vars: any,
previousSibling?: Fiber | null
): Promise<void> {
const shouldUpdate = parentFiber.force || this.shouldUpdate(nextProps);
if (shouldUpdate) {
const __owl__ = this.__owl__;
const fiber = new Fiber(parentFiber, this, this.props, scope, vars, parentFiber.force);
if (!parentFiber.child) {
parentFiber.child = fiber;
} else {
previousSibling!.sibling = fiber;
}
const defaultProps = (<any>this.constructor).defaultProps;
if (defaultProps) {
nextProps = this.__applyDefaultProps(nextProps, defaultProps);
}
await Promise.all([
this.willUpdateProps(nextProps),
__owl__.willUpdatePropsCB && __owl__.willUpdatePropsCB(nextProps)
]);
if (fiber.isCancelled) {
return;
}
this.props = nextProps;
this.__render(fiber);
}
}
/**
* Main patching method. We call the virtual dom patch method here to convert
* a virtual dom vnode into some actual dom.
*/
__patch(vnode) {
const __owl__ = this.__owl__;
const target = __owl__.vnode || document.createElement(vnode.sel!);
__owl__.vnode = patch(target, vnode);
__owl__.currentFiber = null;
}
/**
* The __prepare method is only called by the t-component directive, when a
* subcomponent is created. It gets its scope and vars, if any, from the
* parent template.
*/
__prepare(parentFiber: Fiber, scope: any, vars: any, previousSibling?: Fiber | null) {
const fiber = new Fiber(parentFiber, this, this.props, scope, vars, parentFiber.force);
fiber.shouldPatch = false;
if (!parentFiber.child) {
parentFiber.child = fiber;
} else {
previousSibling!.sibling = fiber;
}
return this.__prepareAndRender(fiber);
}
__getTemplate(qweb: QWeb): string {
let p = (<any>this).constructor;
if (!p.hasOwnProperty("_template")) {
if (p.template) {
p._template = p.template;
} else {
// here, the component and none of its superclasses defines a static `template`
// key. So we fall back on looking for a template matching its name (or
// one of its subclass).
let template: string;
while ((template = p.name) && !(template in qweb.templates) && p !== Component) {
p = p.__proto__;
}
if (p === Component) {
throw new Error(`Could not find template for component "${this.constructor.name}"`);
} else {
p._template = template;
}
}
}
return p._template;
}
async __prepareAndRender(fiber: Fiber) {
try {
await Promise.all([this.willStart(), this.__owl__.willStartCB && this.__owl__.willStartCB()]);
} catch (e) {
fiber.handleError(e);
fiber.vnode = h("div"); // -> we render this div at the end
return Promise.resolve();
}
if (this.__owl__.isDestroyed) {
return Promise.resolve();
}
if (!fiber.isCancelled) {
this.__render(fiber);
}
}
__render(fiber: Fiber) {
const __owl__ = this.__owl__;
if (__owl__.observer) {
__owl__.observer.allowMutations = false;
}
let vnode;
try {
vnode = __owl__.renderFn!(this, {
handlers: __owl__.boundHandlers,
fiber: fiber
});
} catch (e) {
vnode = __owl__.vnode || h("div");
fiber.handleError(e);
}
fiber.vnode = vnode;
if (__owl__.observer) {
__owl__.observer.allowMutations = true;
}
// we apply here the class information described on the component by the
// template (so, something like <MyComponent class="..."/>) to the actual
// root vnode
if (__owl__.classObj) {
vnode.data.class = Object.assign(vnode.data.class || {}, __owl__.classObj);
}
fiber.root.counter--;
fiber.isRendered = true;
}
/**
* Only called by qweb t-component directive
*/
__mount(fiber: Fiber, elm: HTMLElement): VNode {
if (fiber !== this.__owl__.currentFiber) {
fiber = this.__owl__.currentFiber!; // TODO: check if we can remove fiber arg
}
const vnode = fiber.vnode!;
const __owl__ = this.__owl__;
if (__owl__.classObj) {
(<any>vnode).data.class = Object.assign((<any>vnode).data.class || {}, __owl__.classObj);
}
__owl__.vnode = patch(elm, vnode);
__owl__.currentFiber = null;
if (__owl__.parent!.__owl__.isMounted && !__owl__.isMounted) {
this.__callMounted();
}
return __owl__.vnode;
}
/**
* Only called by qweb t-component directive (when t-keepalive is set)
*/
__remount() {
const __owl__ = this.__owl__;
if (!__owl__.isMounted) {
__owl__.isMounted = true;
this.mounted();
}
}
/**
* Apply default props (only top level).
*
* Note that this method does not modify in place the props, it returns a new
* prop object
*/
__applyDefaultProps(props: Object | undefined, defaultProps: Object): Props {
props = props ? Object.assign({}, props) : {};
for (let propName in defaultProps) {
if (props![propName] === undefined) {
props![propName] = defaultProps[propName];
}
}
return <Props>props;
}
}