js/skooma.js

87 lines
3 KiB
JavaScript

/*
A functional HTML generation library.
Example:
html.label(
html.span("Delete everything", {class: ["warning", "important"]}),
html.button("Click", {onClick: e => document.body.innerHTML=""}),
)
or
html.ul([1, 2, 3, 4, 5].map(x => html.li(x)), {class: "numbers"})
*/
const keyToPropName = key => key.replace(/^[A-Z]/, a => "-"+a).replace(/[A-Z]/g, a => '-'+a.toLowerCase())
const insertStyles = (rule, styles) => {
for (let [key, value] of Object.entries(styles))
if (typeof value == "undefined")
rule.removeProperty(keyToPropName(key))
else
rule.setProperty(keyToPropName(key), value.toString())
}
const parseAttribute = (attribute) => {
if (typeof attribute == "string" || typeof attribute == "number")
return attribute
else if ("join" in attribute)
return attribute.join(" ")
else
return JSON.stringify(attribute)
}
const createPromiseNode = promise => {
const comment = document.createComment(`Awaiting ${promise}`)
promise.then(result => {parseArgs(comment.parentNode, comment, result); comment.remove()})
return comment
}
const parseArgs = (element, before, ...args) => {
if (element.content) element = element.content
for (let arg of args)
if (typeof arg == "string" || typeof arg == "number")
element.insertBefore(document.createTextNode(arg), before)
else if (typeof arg == "function")
arg(element)
else if ("nodeName" in arg)
element.insertBefore(arg, before)
else if (arg.constructor?.name === "Promise")
element.insertBefore(createPromiseNode(arg), before)
else if ("length" in arg)
parseArgs(element, before, ...arg)
else
for (let key in arg)
if (key == "style" && typeof(arg[key])=="object")
insertStyles(element.style, arg[key])
else if (key == "dataset" && typeof(arg[key])=="object")
for (let [key2, value] of Object.entries(arg[key]))
element.dataset[key2] = parseAttribute(value)
else if (key == "shadowRoot")
parseArgs((element.shadowRoot || element.attachShadow({mode: "open"})), null, arg[key])
else if (typeof arg[key] === "function")
element.addEventListener(key.replace(/^on[A-Z]/, x => x.charAt(x.length-1).toLowerCase()), arg[key])
else if (arg[key] === true)
{if (!element.hasAttribute(key)) element.setAttribute(key, '')}
else if (arg[key] === false)
element.removeAttribute(key)
else
element.setAttribute(key, parseAttribute(arg[key]))
}
const node = (name, args, options) => {
let element
if (options.nameFilter) name = options.nameFilter(name)
if (options.xmlns)
element = document.createElementNS(options.xmlns, name)
else
element = document.createElement(name)
parseArgs(element, null, args)
return element
}
const nameSpacedProxy = (options={}) => new Proxy(Window, {
get: (target, prop, receiver) => { return (...args) => node(prop, args, options) },
has: (target, prop) => true,
})
export const html = nameSpacedProxy({nameFilter: name => name.replace(/([a-z])([A-Z])/g, "$1-$2").toLowerCase()})
export const svg = nameSpacedProxy({xmlns: "http://www.w3.org/2000/svg"})