##// END OF EJS Templates
added pipe method to observable
added pipe method to observable

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r109:4a375b9c654a default
r114:e9a9ed6d7647 v1.5.0 default
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render.ts
112 lines | 3.0 KiB | video/mp2t | TypeScriptLexer
import { TraceSource } from "@implab/core-amd/log/TraceSource";
import { isPromise } from "@implab/core-amd/safe";
import { id as mid } from "module";
import { IScope, Scope } from "./Scope";
import { isNode, isRendition, isWidget } from "./traits";
const trace = TraceSource.get(mid);
interface Context {
scope: IScope;
hooks?: (() => void)[];
}
let _context: Context = {
scope: Scope.dummy
};
const guard = (cb: () => unknown) => {
try {
const result = cb();
if (isPromise(result)) {
const warn = (ret: unknown) => trace.error("The callback {0} competed asynchronously. result = {1}", cb, ret);
result.then(warn, warn);
}
} catch (e) {
trace.error(e);
}
};
export const beginRender = (scope: IScope = getScope()) => {
const prev = _context;
_context = {
scope,
hooks: []
};
return endRender(prev);
};
/**
* Completes render operation
*/
const endRender = (prev: Context) => () => {
const { hooks } = _context;
if (hooks)
hooks.forEach(guard);
_context = prev;
};
export const renderHook = (hook: () => void) => {
const { hooks } = _context;
if (hooks)
hooks.push(hook);
else
guard(hook);
};
export const refHook = <T>(value: T, ref: JSX.Ref<T>) => {
const { hooks, scope } = _context;
if (hooks)
hooks.push(() => ref(value));
else
guard(() => ref(value));
scope.own(() => ref(undefined));
};
/** Returns the current scope */
export const getScope = () => _context.scope;
/** Schedules the rendition to be rendered to the DOM Node
* @param rendition The rendition to be rendered
* @param scope The scope
*/
export const render = (rendition: unknown, scope = Scope.dummy) => {
const complete = beginRender(scope);
try {
return getItemDom(rendition);
} finally {
complete();
}
};
/** Renders DOM element for different types of the argument. */
export const getItemDom = (v: unknown) => {
if (typeof v === "string" || typeof v === "number" || v instanceof RegExp || v instanceof Date) {
// primitive types converted to the text nodes
return document.createTextNode(v.toString());
} else if (isNode(v)) {
// nodes are kept as is
return v;
} else if (isRendition(v)) {
// renditions are instantiated
return v.getDomNode();
} else if (isWidget(v)) {
// widgets are converted to it's markup
return v.domNode;
} else if (typeof v === "boolean" || v === null || v === undefined) {
// null | undefined | boolean are removed
return document.createDocumentFragment();
} else if (v instanceof Array) {
// arrays will be translated to document fragments
const fragment = document.createDocumentFragment();
v.map(item => getItemDom(item))
.forEach(node => fragment.appendChild(node));
return fragment;
} else {
// bug: explicit error otherwise
throw new Error(`Invalid parameter: ${String(v)}`);
}
};