html要素を取得

parse_html.js

var titles = document.getElementsByTagName("title");
var title = (titles.length > 0) ? titles[0].innerHTML: "";
var metas = document.getElementsByTagName("meta");
var description = "";
var keywords = "";
for (i=0; i<metas.length; i++){
    var meta_name = metas[i].getAttribute("name");
    if (meta_name=="description"){
        description = metas[i].getAttribute("content");
    } else if (meta_name=="keywords"){
        keywords = metas[i].getAttribute("content");
    }
}
var h1s = document.getElementsByTagName("h1");
var h1 = (h1s.length > 0) ? h1s[0].innerHTML : "";

console.log("title: " + title);
console.log("description: " + description);
console.log("keywords: " + keywords);
console.log("h1: " + h1);
console.log("h1 is " + h1s.length);