I am just getting into using the theme customizer in WordPress. I found a great answer on this site about adding a slider and I got it working just fine. I was reading in the codex about the theme-customizer and it says that after you add your settings, you need to add to the theme-customizer.js file to update your settings. Does this really need to be done? I noticed that without adding my settings to this file that the slider images that I just got working seem to work just fine. So I am a little confused on this step. I can't even find the information that the codex is talking about in the default theme.
If you check "Step Two" in this link You will see that it is talking about adding a bunch of javascript to the theme. I don't see that it is needed. Things seem to update just fine without adding any javascript.
Even with these settings. The codex says that this stage is optional. I have added 3 photo uploads for a slider. Just to test out the customizer. The theme updates in real time without adding this kind of information about my new controls
$wp_customize->get_setting( 'blogname' )->transport = 'postMessage';
$wp_customize->get_setting( 'blogdescription' )->transport = 'postMessage';
$wp_customize->get_setting( 'header_textcolor' )->transport = 'postMessage';
$wp_customize->get_setting( 'background_color' )->transport = 'postMessage';