lyng/lyngio/stdlib/lyng/io/html.lyng

package lyng.io.html

import lyng.stdlib

fun escapeHtml(text: String): String {
    val amp: String = text.replace("&", "&")
    val lt: String = amp.replace("<", "&lt;")
    lt.replace(">", "&gt;")
}

fun escapeHtmlAttr(text: String): String {
    val escaped: String = escapeHtml(text)
    val quoted: String = escaped.replace("\"", "&quot;")
    quoted.replace("'", "&#39;")
}

class HtmlTag(name: String, isVoid: Bool = false) {
    val name = name
    val isVoid = isVoid
    var attributes = ""
    var inner = ""

    fun attr(name: String, value: Object): HtmlTag {
        attributes += " " + name + "=\"" + escapeHtmlAttr(value.toString()) + "\""
        this
    }

    fun flag(name: String): HtmlTag {
        attributes += " " + name
        this
    }

    fun id(value: String): HtmlTag = attr("id", value)

    fun classes(value: String): HtmlTag = attr("class", value)

    fun addText(text: String): void {
        inner += escapeHtml(text)
    }

    fun raw(html: String): void {
        inner += html
    }

    fun child(tagName: String, block: HtmlTag.()->void): void {
        val child = HtmlTag(tagName)
        with(child) { block(this) }
        inner += child.render()
    }

    fun voidChild(tagName: String, block: HtmlTag.()->void): void {
        val child = HtmlTag(tagName, true)
        with(child) { block(this) }
        inner += child.render()
    }

    fun tag(name: String, block: HtmlTag.()->void): void { child(name, block) }

    fun voidTag(name: String, block: HtmlTag.()->void): void { voidChild(name, block) }

    fun render(): String {
        if (isVoid) "<" + name + attributes + ">"
        else "<" + name + attributes + ">" + inner + "</" + name + ">"
    }

    fun head(block: HtmlTag.()->void): void { child("head", block) }
    fun body(block: HtmlTag.()->void): void { child("body", block) }
    fun title(block: HtmlTag.()->void): void { child("title", block) }
    fun main(block: HtmlTag.()->void): void { child("main", block) }
    fun section(block: HtmlTag.()->void): void { child("section", block) }
    fun article(block: HtmlTag.()->void): void { child("article", block) }
    fun header(block: HtmlTag.()->void): void { child("header", block) }
    fun footer(block: HtmlTag.()->void): void { child("footer", block) }
    fun nav(block: HtmlTag.()->void): void { child("nav", block) }
    fun div(block: HtmlTag.()->void): void { child("div", block) }
    fun span(block: HtmlTag.()->void): void { child("span", block) }
    fun p(block: HtmlTag.()->void): void { child("p", block) }
    fun a(href: String, block: HtmlTag.()->void): void {
        child("a") {
            attr("href", href)
            block(this)
        }
    }
    fun ul(block: HtmlTag.()->void): void { child("ul", block) }
    fun ol(block: HtmlTag.()->void): void { child("ol", block) }
    fun li(block: HtmlTag.()->void): void { child("li", block) }
    fun h1(block: HtmlTag.()->void): void { child("h1", block) }
    fun h2(block: HtmlTag.()->void): void { child("h2", block) }
    fun h3(block: HtmlTag.()->void): void { child("h3", block) }
    fun h4(block: HtmlTag.()->void): void { child("h4", block) }
    fun h5(block: HtmlTag.()->void): void { child("h5", block) }
    fun h6(block: HtmlTag.()->void): void { child("h6", block) }
    fun strong(block: HtmlTag.()->void): void { child("strong", block) }
    fun em(block: HtmlTag.()->void): void { child("em", block) }
    fun code(block: HtmlTag.()->void): void { child("code", block) }
    fun pre(block: HtmlTag.()->void): void { child("pre", block) }
    fun script(block: HtmlTag.()->void): void { child("script", block) }
    fun style(block: HtmlTag.()->void): void { child("style", block) }

    fun meta(block: HtmlTag.()->void): void { voidChild("meta", block) }
    fun link(block: HtmlTag.()->void): void { voidChild("link", block) }
    fun img(block: HtmlTag.()->void): void { voidChild("img", block) }
    fun br(block: HtmlTag.()->void): void { voidChild("br", block) }
    fun input(block: HtmlTag.()->void): void { voidChild("input", block) }

    fun metaCharset(charset: String = "utf-8"): void {
        meta { attr("charset", charset) }
    }

    fun stylesheet(href: String): void {
        link {
            attr("rel", "stylesheet")
            attr("href", href)
        }
    }

    fun img(src: String, alt: String = ""): void {
        voidChild("img") {
            attr("src", src)
            if (alt != "") attr("alt", alt)
        }
    }

    fun input(type: String, name: String = "", value: String = ""): void {
        voidChild("input") {
            attr("type", type)
            if (name != "") attr("name", name)
            if (value != "") attr("value", value)
        }
    }
}

context(HtmlTag)
fun String.unaryPlus(): void {
    this@HtmlTag.addText(this)
}

fun html(block: HtmlTag.()->void): String {
    val root = HtmlTag("html")
    with(root) { block(this) }
    "<!doctype html>" + root.render()
}