more work on databinding and templating

This commit is contained in:
Bruno Windels 2019-06-13 00:41:45 +02:00
parent c7163a0554
commit eb2eb291d3
5 changed files with 190 additions and 142 deletions

View file

@ -1,29 +1,12 @@
import { li } from "./html.js";
import TemplateView from "./TemplateView.js";
export default class RoomTile {
constructor(viewModel) {
this._viewModel = viewModel;
this._root = null;
}
mount() {
this._root = li(null, this._viewModel.name);
return this._root;
}
unmount() {
}
update() {
// no data-binding yet
this._root.innerText = this._viewModel.name;
export default class RoomTile extends TemplateView {
render(t) {
return t.li(vm => vm.name);
}
// called from ListView
clicked() {
this._viewModel.open();
}
root() {
return this._root;
}
}

151
src/ui/web/Template.js Normal file
View file

@ -0,0 +1,151 @@
import { setAttribute, text, TAG_NAMES } from "./html.js";
// const template = new Template(vm, t => {
// return t.div({onClick: () => this._clicked(), className: "errorLabel"}, [
// vm => vm.label,
// t.span({className: vm => t.className({fatal: !!vm.fatal})}, [vm => vm.error])
// ]);
// });
/*
supports
- event handlers (attribute fn value with name that starts with on)
- one way binding of attributes (other attribute fn value)
- one way binding of text values (child fn value)
- refs to get dom nodes
- className binding returning object with className => enabled map
missing:
- create views
*/
export default class Template {
constructor(value, render) {
this._value = value;
this._refs = {};
this._eventListeners = [];
this._bindings = [];
this._render = render;
}
className(obj) {
Object.entries(obj).filter(([, value]) => value).map(([key]) => key).join(" ");
}
root() {
if (!this._root) {
this._root = this._render(this, this._value);
}
return this._root;
}
ref(name) {
return this._refs[name];
}
update(value) {
this._value = value;
for (const binding of this._bindings) {
binding();
}
}
detach() {
for (let {node, name, fn} of this._eventListeners) {
node.removeEventListener(name, fn);
}
}
attach() {
for (let {node, name, fn} of this._eventListeners) {
node.addEventListener(name, fn);
}
}
_addRef(name, node) {
this._refs[name] = node;
}
_addEventListener(node, name, fn) {
this._eventListeners.push({node, name, fn});
}
_setAttributeBinding(node, name, fn) {
let prevValue = undefined;
const binding = () => {
const newValue = fn(this._value);
if (prevValue !== newValue) {
prevValue = newValue;
setAttribute(node, name, newValue);
}
};
this._bindings.push(binding);
binding();
}
_addTextBinding(fn) {
const initialValue = fn(this._value);
const node = text(initialValue);
let prevValue = initialValue;
const binding = () => {
const newValue = fn(this._value);
if (prevValue !== newValue) {
prevValue = newValue;
node.textContent = newValue+"";
}
};
this._bindings.push(binding);
return node;
}
el(name, attributes, children) {
if (attributes) {
// valid attributes is only object that is not a DOM node
// anything else (string, fn, array, dom node) is presumed
// to be children with no attributes passed
if (typeof attributes !== "object" || attributes.nodeType === Node.ELEMENT_NODE || Array.isArray(attributes)) {
children = attributes;
attributes = null;
}
}
const node = document.createElement(name);
if (attributes) {
for(let [key, value] of Object.entries(attributes)) {
const isFn = typeof value === "function";
if (key === "ref") {
this._refs[value] = node;
} else if (key.startsWith("on") && key.length > 2 && isFn) {
const eventName = key.substr(2, 1).toLowerCase() + key.substr(3);
const handler = value;
this._addEventListener(node, eventName, handler);
} else if (isFn) {
this._addAttributeBinding(node, key, value);
} else {
setAttribute(node, key, value);
}
}
}
if (children) {
if (!Array.isArray(children)) {
children = [children];
}
for (let child of children) {
if (typeof child === "string") {
child = text(child);
} else if (typeof c === "function") {
child = this._addTextBinding(child);
}
node.appendChild(child);
}
}
return node;
}
}
for (const tag of TAG_NAMES) {
Template.prototype[tag] = function(...params) {
this.el(tag, ... params);
};
}

View file

@ -0,0 +1,29 @@
import Template from "./Template.js";
export default class TemplateView {
constructor(value) {
this._template = new Template(value, (t, value) => this.render(t, value));
}
render() {
throw new Error("render not implemented");
}
mount() {
const root = this._template.root();
this._template.attach();
return root;
}
root() {
return this._template.root();
}
unmount() {
this._template.detach();
}
update(value) {
this._template.update(value);
}
}

View file

@ -31,6 +31,11 @@ export function text(str) {
return document.createTextNode(str);
}
export const TAG_NAMES = [
"ol", "ul", "li", "div", "h1", "h2", "h3", "h4", "h5", "h6",
"p", "strong", "em", "span", "img", "section", "main", "article", "aside",
"pre", "button"];
export function ol(... params) { return el("ol", ... params); }
export function ul(... params) { return el("ul", ... params); }
export function li(... params) { return el("li", ... params); }

View file

@ -1,120 +0,0 @@
import { setAttribute, addChildren, text } from "./html.js";
function renderTree() {}
const tree = renderTree(vm, t => {
return t.div({onClick: () => this._clicked(), className: "errorLabel"}, [
vm => vm.label,
t.span({className: vm => {{fatal: !!vm.fatal}}}, [vm => vm.error])
]);
});
tree.root
tree.detach()
tree.updateBindings(vm);
class Tree {
constructor(value, render) {
this._ctx = new TreeContext(value);
this._root = render(this._ctx);
}
ref(name) {
return this._ctx._refs[name];
}
detach() {
for (let {node, name, fn} of this._ctx._eventListeners) {
node.removeEventListener(name, fn);
}
}
}
class TreeContext {
constructor(value) {
this._value = value;
this._refs = {};
this._eventListeners = [];
this._bindings = [];
}
_addRef(name, node) {
this._refs[name] = node;
}
_addEventListener(node, name, fn) {
node.addEventListener(name, fn);
this._eventListeners.push({node, event, fn});
}
_setAttributeBinding(node, name, fn) {
let prevValue = undefined;
const binding = () => {
const newValue = fn(this._value);
if (prevValue !== newValue) {
prevValue = newValue;
setAttribute(node, name, newValue);
}
};
this._bindings.push(binding);
binding();
}
_setTextBinding(fn) {
const initialValue = fn(this._value);
const node = text(initialValue);
let prevValue = initialValue;
const binding = () => {
const newValue = fn(this._value);
if (prevValue !== newValue) {
prevValue = newValue;
node.textContent = newValue+"";
}
};
this._bindings.push(binding);
}
el(name, attributes, children) {
const node = document.createElement(name);
for(let [key, value] of Object.entries(attributes)) {
const isFn = typeof value === "function";
if (key.startsWith("on") && key.length > 2 && isFn) {
const eventName = key.substr(2, 1).toLowerCase() + key.substr(3);
const handler = value;
this._addEventListener(node, eventName, handler);
} else if (isFn) {
this._addAttributeBinding(node, key, value);
} else {
setAttribute(node, key, value);
}
}
addChildren(node, children);
return node;
}
ol(... params) { return this.el("ol", ... params); }
ul(... params) { return this.el("ul", ... params); }
li(... params) { return this.el("li", ... params); }
div(... params) { return this.el("div", ... params); }
h1(... params) { return this.el("h1", ... params); }
h2(... params) { return this.el("h2", ... params); }
h3(... params) { return this.el("h3", ... params); }
h4(... params) { return this.el("h4", ... params); }
h5(... params) { return this.el("h5", ... params); }
h6(... params) { return this.el("h6", ... params); }
p(... params) { return this.el("p", ... params); }
strong(... params) { return this.el("strong", ... params); }
em(... params) { return this.el("em", ... params); }
span(... params) { return this.el("span", ... params); }
img(... params) { return this.el("img", ... params); }
section(... params) { return this.el("section", ... params); }
main(... params) { return this.el("main", ... params); }
article(... params) { return this.el("article", ... params); }
aside(... params) { return this.el("aside", ... params); }
pre(... params) { return this.el("pre", ... params); }
}