elm-scripting/dom.js

function Node(parent, tag) {
	this.parentNode =  parent; // Node
	this.pos = 0; // position in siblings list
	this.tagName =  tag;
	this.text =  null;
	// attributes are stored directly on the node object
	// see https://github.com/elm/virtual-dom/blob/master/src/Elm/Kernel/VirtualDom.js#L511
	this.children =  [];  // List of Node
	this.replaceChild =  (newNode, domNode) => {
		this.children[domNode.pos-1] = newNode;
		newNode.pos = domNode.pos;
  };
	if (parent != null) {
		this.pos = parent.children.push(this);
	}
	this.appendChild = (node) => {
		node.pos = this.children.push(node);
	}
  this.dump = (d=0) => {
  	if (this.text != null) {
  		print(this.text);
  		return
  	}
  	std.printf("<%s", this.tagName)
  	// Set.difference(other) is not avalable in qjs
		for (a of Object.keys(this)) {
			if (!NodeKeys.has(a)) {
				std.printf(' %s="%s"', a, this[a])
			}
		}
		if (this.children.length==0) {
			print("/>")
		} else {
	  	print(">")
	  	for (c of this.children) {
	  		c.dump(d+1)
	  	}
	  	print("</"+this.tagName+">");
		}
  }
	return this;
}

var document = new Node(null, "document");
var target = new Node(document, "target");
const NodeKeys = new Set(Object.keys(target));

// getElementById is only used once, to get node Elm must hook into.
// so we don't need a full fledge implementation with lookup facilities
// just to return the target node
document.getElementById = (_id) => { return target}

document.createElement = (tag) => new Node(null, tag);
document.createTextNode = (text) => { t = new Node(null, "#text" ); t.text = text; return t }

try {

// here will come the Elm app code