Christian Heilmann

Training new developers in the valley – Day 2

Friday, July 25th, 2008 at 5:06 pm

On the second day of the current Juku program we covered the “read” sections of DOM scripting: attributes, node properties and how to navigate around the document with a certain node as the starting point (nextSibling,previousSibling,parentNode,childNodes…).

  • We also talked in detail about nodeTypes and how to recognize what is an element and what is a text node, which of course brought up the concept of whitespace in HTML as annoying “node-noise”.
  • We covered the difference between element.attribute and element.getAttribute(attribute), especially when it comes to reading out the href attribute of links.
  • We did a script planning session on a whiteboard analyzing the HTML of a document to find out the shortest way to reach a certain element discussing various approaches.
  • We covered manipulation of the style property, its dangers (mixing presentation and structure, hurting maintainability) and its good uses (creating same-height columns using offsetHeight).
  • We covered avoiding the style property by dynamically adding CSS classes and the problems with this (testing for existing classes)
  • We covered cutting down your DOM scripting to the lowest form, avoiding large looping and conditional testing by using getElementsByTagName instead of traversing the node tree.
  • We covered changing of text node content by manipulating the nodeValue property

Today we’ll start creating new content using the DOM.

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