LinkReplaceCommand.ts
import { HtmlSsgContext, HtmlSsgFile, Link, ReplaceCommand } from "ssg-api"
import { HtmlRR0SsgContext } from "./RR0SsgContext"
export interface LinkHandler<C extends HtmlSsgContext> {
start(context: C): Link | undefined
contents(context: C): Link | undefined
prev(context: C): Link | undefined
next(context: C): Link | undefined
}
/**
* Convert meta <link> to HTML <nav> links.
*/
export class LinkReplaceCommand<C extends HtmlRR0SsgContext = HtmlRR0SsgContext> implements ReplaceCommand<C> {
constructor(protected defaultHandler?: LinkHandler<C>) {
}
async execute(context: C): Promise<HtmlSsgFile> {
const inputFile = context.inputFile
const outputFile = context.outputFile
const dom = outputFile.dom
const outputDoc = outputFile.document;
const ul = outputDoc.querySelector("nav ul")
if (!ul) {
context.error("Could not find nav list in " + context.outputFile.name)
return inputFile
}
const relStart = inputFile.links.start || this.defaultHandler?.start(context)
if (relStart) {
ul.appendChild(this.linkItem(context, relStart));
}
const relContents = inputFile.links.contents || this.defaultHandler?.contents(context)
if (relContents) {
ul.appendChild(this.linkItem(context, relContents));
}
const relPrev = inputFile.links.prev || this.defaultHandler?.prev(context)
if (relPrev) {
ul.appendChild(this.linkItem(context, relPrev));
}
const relNext = inputFile.links.next || this.defaultHandler?.next(context)
if (relNext) {
ul.appendChild(this.linkItem(context, relNext));
}
outputFile.dom = dom
return outputFile
}
async contentStepEnd() {
// NOP
}
protected linkItem(context: HtmlRR0SsgContext, link: Link): HTMLLIElement {
const outputDoc = context.outputFile.document
const a = outputDoc.createElement("a")
a.className = link.type
a.textContent = link.text
a.href = link.url
const li = outputDoc.createElement("li")
li.appendChild(a)
li.title = context.messages.nav[link.type]
return li;
}
}