LagartoDOM

Parse HTML to a DOM tree.

LagartoDOM parses HTML content and creates a DOM tree from it. It is based on LagartoParser. The created DOM is convenient to traverse and manipulate. However, if you need ultimate performance, go with the event-based LagartoParser.

Let's see LagartoDom in action:

Document document = new LagartoDOMBuilder()
.parse("<html><h1>Hello</h1></html>");

Node html = document.getChild(0);
Node h1 = html.getFirstChild();

System.out.println(h1.getTextContent());				// Hello

Text text = (Text) h1.getFirstChild();
System.out.println(text.getTextValue());				// Hello

System.out.println(text.getCssPath());				  // html h1

It's simple as that. As said, the DOM tree is created. It consists of Node elements. Each Node contains a bunch of methods related to tree traversing, such as getChild(index), getFirstChild(), getParentNode(), getChildNodes(), etc.

Node contains also getters for node name, attributes, node values. Node can be detached from the tree or attached at some point. Element is a special type of the Node that represents elements, and there is a whole subset of methods that deal only with elements.

Finally, you can render DOM tree or any Node back to HTML content.

Parsing specification

LagartoDOM follows only a subset of the official DOM-building specification. Here is why!

By default, LagartoDOM follows all the rules that do not involve any movements of DOM nodes. This is done on purpose. The idea is to get the exact tree to what you have provided. For example, if you pass HTML with some tags that are not supposed to be nested, LagartoDOM would not complain and you will get exactly what you have on input.

In most cases, this will be perfectly fine, as developers are probably not using all the tricks of HTML5 for the sake of better readability.

Still, you can turn on some more rules, you can turn them on! In that case, the resulting DOM tree can be modified per HTML5 rules. I have implemented the most common of these rules and exceptions, but haven't covered them all (yet). So if you have some weird HTML, you might get a different tree than what you get in a browser.

LagartoDOM is not (yet) a strict implementation of HTML5 DOM-building rules, but it is good enough for most cases!

Carry on :)

PreviousFAQNextParsing modes

Last updated