Expressing IT

Yesterday,  like every other “Ground Hog  Day” ,  I was working on some CSS/tableless  layouts. All was going well in IE 7, FF 3 and Chrome, untill suddenly,   I saw some un-ignorable margins seen only in Google Chrome.   Though very strange and worring, It  was some new bug/issue that I had come accross, there was  finally some spice in my mundane work . Sad (but nice) it got fixed within a few minutes of the probe…

Basically ,  It looked like  Google Chrome ignored my CSS Resets  ( margin:0px).  It actually was  caused by the user agent stylesheet (-webkit-padding-start:40px).  So the solution was to reset this style by setting padding:0 the misbehaving elements .
A  good way to prevent this problem from happening to any element is use a global CSS Rest as follows

*{ margin:0; padding:0; }

What is User Agent Style Sheets (Specification) ?
The following  excerpt is taken  from http://meiert.com/en/blog/20070922/user-agent-style-sheets/ , follow link to read more on User Agent Style Sheets

CSS 1 introduces the idea by stating that each User Agent (UA, often a ‘web browser’ or ‘web client’) will have a default style sheet that presents documents in a reasonable – but arguably mundane – manner. CSS 2 says that conforming user agents must apply a default style sheet (or behave as if they did) and that a user agent’s default style sheet should present the elements of the document language in ways that satisfy general presentation expectations for the document language; CSS 3 is likely to be of the same mind.

Since the CSS specifications leave it up to implementations whether to use a “real” style sheet for default display or not, it’s not astonishing that you don’t find a default style sheet in every browser’s installation folder. Unlike Microsoft’s Internet Explorer as well as Opera, for example (and as far as I know), Gecko browsers like Firefox and Netscape Navigator (look for “html.css”) but also Konqueror make it rather simple to comprehend their default styling.

This ones old school , but as usual it is my memory supplement …
So is disabled=”true” and disabled=”false” same?Yes
… Don’t believe, well! thats the way it is … here is some quick explanation…
“disabled” is an attribute of any form element/field and hence can accept any value by its nature.

As long as this attribute is present, the element will be disabled regardless of its value. for eg.
<input type=”text” value=”This is disabled” disabled>
<input type=”text” value=”This is disabled” disabled=”disabled”>
<input type=”text” value=”This is disabled” disabled=”true”>
<input type=”text” value=”This is disabled” disabled=”false”>

All of the above will make the this form field “DISABLED”.

Simply not providing the attribute “DISABLED” keeps the Field “ABLED” … like below

<input type=”text” value=”This is not disabled” />

Remember “Any value (or no value at all) of the disabled attribute, the browser will render it disabled” . To keep things clear in our minds W3C recommends that we use disabled=”disabled” in these situations.

This is difference though when we use this attribute in javascript …

document.form.element.disabled = true; //the element will be disabled
document.form.element.disabled = false; //the element will be enabled

The above arguments are also true for these attributes and elements :

• checked (radio button and checkbox)
• selected (option)
• nowrap (td)

Google starts a movement prompt people to dump IE6 … By bugging IE6 users with a POPUP on page load… may be not a very good idea … but being a UI developer , I have to join this band wagon … one less browser for me worry about … Sorry selfish it is! but I have include this javascript … ( TRY THIS PAGE IN IE6) …
Hey ! and on the brighter note … See it is a display of the POWER of JAVASCRIPT …. it can even bring down a giant (or once it was )

SO … Help rid the world of IE6 with one line of javascript!

http://code.google.com/p/sevenup/

With another browser to take care from tomorrow! (IE8 comes out of its Beta State tomorrow) … Its really high time IE6 is given its Long Due Mercy Death … United we stand for the fall of IE6 

“IE6 is the new Netscape 4. The hacks needed to support IE6 are increasingly viewed as excess freight. Like Netscape 4 in 2000, IE6 is perceived to be holding back the web.”

Jeff Zeldman, standards guru

And meanwhile  for those  like me who will be flooded with calls of  breaking CSS layouts in IE8,  here is the old work around/fix using Meta Tags (meta http-equiv=”X-UA-Compatible”) you could try…

Mis-behaving IE8 : CSS Layout breakages (Targeting a browser version using Meta Tags in IE8)

Heres another little peice of Javascript trickery that I had to dig around because the situation commaned it. In one of my web sites, I had this situation where I had to implement “windows.onload” twice. The first thing that would came to an inexperienced mind like mine ( I have to honestly say that, since I have been using javascript Frameworks and libraries, I have forgotton to do simple things on my own… sad but true), is the following method…

window.onload=onloadfn1;
window.onload=onloadfn2;
window.onload=onloadfn3;
etc...

Sorry to say but, this wont work… dont want to discuss the execution science of Javascript much … but according to my recent experience, only the last function (onloadfn3) will ill actually get executed.

In normal situations, unlike mine (which I’ll talk about a little later)… you could do one of the following to execute mutliple onload functions ….

OR something like this

function doOnLoad() {
        onloadfn1();
        onloadfn2();
        onloadfn3();
}
window.onload = doOnLoad;

For my current situation , I cannot use either of the above…
Why did I need to call windows.onload twice, rather that calling two functions within a single onload function? Here is quick look at my problem statement…

“My Site pages are structured like the WORDPRESS theme…. i.e. there is a common Header.php and Footer.php that gets included into all the site pages. There is an onload function implementaion in the Footer.php to do some common onload functions. AND there are few pages that need to something of their own ONLOAD , apart from those done by the common onload function. If I assign callback function directly to the window.onload handler, it will over-ride previously assigned callbacks in the Footer.php”

…. Is my problem understood ?

Well! there are few solutions that I did find. They all are very similar and mainly implementions of a solution given by Simon Willison (http://simonwillison.net/2004/May/26/addLoadEvent/)…

Solution :

Simply add this javascript code to site …

function addLoadEvent(func) {
    var oldonload = window.onload;
    if (typeof window.onload != 'function') {
       window.onload = func
    } else {
       window.onload = function() {
           if (oldonload) {
                  oldonload()
          }
          func()
       }
   }
}

And call it instead of the usual “windows.onload”

addLoadEvent(FunctionToRunOnPageLoad);
addLoadEvent(function() {
/* more code to run on page load *
}); 

Advantages of this code snippet …
1. Primarily, It lets you have multiple windows.onload events, called from seperate parts of your code, without overridding the previous definition
2. It is really unobtrusive. It can be placed in a file with your other scripts or in a separate file.
3. It works even if window.onload has already been set.

Another quick tut. Here is something simple and nice using the POWER of CSS… but was difficult concieve( and it surely wasn’t me) to begin with . Adding Dropshadow, might be a peice of cake for many of us, using some image editing tools like Photoshop anf Fireworks etc.
The reason why , I opted for drop shadow using CSS is that , usually while creating a page design/html of an application , the requirements keep iterating. What I mean is , In a existing web site with many images, like the ones displaying freinds list or an image gallery, it will be difficult to reprocess the entire load of images that had been already unloaded to add or remove the shadows, for that matter.
So If you have done a little forward thinking while creating the HTMLS to add these extra divisions or usually the situation is that you have a Loop Logic generating these icons/thumbnails in XSL, PHP. JAVA or any other programming /scripting language, you can add it anytime, then is just the matter of show and hiding these shadows using the CSS Display property,as per the clients ever changing requirements … I havn’t done this sort of forward thinking before this … but ahev started now!

In the example below, the original image is shadow free and the dropshadows are applied as required! ALSO, I have gone a little extra, by using the tricks of my earlier Tut ( Well! these probably are shortest variety of Tutorials , so it is only justified calling them “Tut”‘s ) about Using CSS Clip Property for show off only

Original Image

CSS DropShadow Results

View Demo  | Download sourcefiles

Why do I want to understand this??? … Humm!!!!

Most of CSS writers would agree that CSS Clip property is probably one of most un-used CSS properties. It was so true for me too and was most happy to neglect it , until I started modifying the MOOTOOLS TWO Knob (Pin) Slider Component(with Range Indicator).

There was a good suggestion from one of the component users to modify the Slider Component using clipped backgroud images( against a variable width division) to indicate the slider range. Thus came my time to enter the fun but un-chartered (for me ofcourse) waters of the CSS Clip property.

Well! how difficult it can be? Not much at all …YES and NO. The syntax to use the CSS Clip property is pretty upright but the meaning/usuage is a bit croocked. With a memory like mine, everytime I sit to rework on my Slider Script… I have tokeep referring back to usage of this CLIP property , to remind myself the logic that I have created in my script …. HENCE! thought to pen it down, with a hope to remember it the future ( and also for the benefit of those who seem boggled by the CSS Clip Property)

What does CSS Clip do?

Clip is part of the visual effects module of CSS 2.1 . Simply put, its job is to place a visible window on top of an object that is being clipped , hence clipping images and creating thumbnails without having to create additional files( I have already put this feature to better use in the Slider Component )

Using the CSS Clip property, you can create a clipping using the rect shape. Like many other CSS Properties (like margin, padding etc),using rect requires four coordinates Top, Right, Bottom, Left (TRBL). The croocked nature of this property reflects when you take a closer look at how clip calculates the clipping region , using these four coordinates (sends brain into a toss for a while). Now to confuse you the bottom starts from the top, and the right starts from the left. . You see what i said? …. Hence this post …

This little confusion can easily disappear , with this visual explanation of the CSS Clip/rect property as below!!!!

CSS Clip Requirements

The task we have started is to clip the following Thumbnail image into a squarer looking image (and also a wide-angle image)

Original Thumbnal/Image	Clip Requirements for Sqaure Thumbmail

CSS Clip Results

View Demo  |  Download sourcefiles

Sometimes to keep the pageweight down … we have split our scripts into fragments…These javascript fragments can be loaded as and when required ( on an event or on click of a  link or button etc.).

Loading Javascripts dynamically is simple and pretty straight forward  as below… 

<script type=“text/javascript”>
function loadNewScript(source){
  var s = document.createElement(‘script’);
  s.setAttribute(‘type’,'text/javascript’);
  s.setAttribute(‘src’, source);
  document.body.appendChild(s);
}
</script>

and you can have the following call link anywhere in the body , or you can have this script “onLoad” of the document itself…

<a href=“javascript:loadNewScript(‘myDynamicScript.js’);”>Load Dynamic Script</a>

or

<body onload=”loadNewScript(‘myDynamicScript.js’);”>

If you are css person, you would know the pain in getting your layouts working cross-browser. IE8 is yet another spanner in the works for us developers. Anywaz! if you hit upon this issue, Like I did yesterday, where your perfectly working CSS in IE7 (and earlier) and  Firefox  has suddenly started throwing tantrums in IE8 , TRY This … It nicely seemed to fix my problems for the moment ….

Using Meta declaration, we can specify the rendering engine we would like IE8 to use. So to force IE8 to render as IE7 … Insert the following Meta Tag into the head of your document:-

<meta http-equiv=”X-UA-Compatible” content=”IE=7″ />

By default IE Meta would be:-

<meta http-equiv=”X-UA-Compatible” content=”IE=8″ />
which would make IE8 render the page using the new standards mode.

If required, this syntax could be used to accomodate for other browsers as below:

<meta http-equiv=”X-UA-Compatible” content=”IE=8;FF=3;OtherUA=4″ />

MORE About DOCTYPES :

IF you are yet unfamiliar with the sort of animal called “Doctype” … here is some quick read
What are DOCTYPES? What are BROWSER QUIRKS & STRICT Mode?
Setting the DOCTYPE in XSL

For a more in depth understanding about DOCTYPES , try visiting these links…
A List Apart : Fix Your Site With the Right DOCTYPE!
A List Apart : Beyond DOCTYPE: Web Standards, Forward Compatibility, and IE8

Note: Though many of us HTML/CSS people have been neglecting the importance of DOCTYPE decleration in our documents , Setting the right DOCTYPE , is usually the answer to most cross browser issues.

With a variety of Carousels out there , many for Mootools as well, I still decided to write my own Carousel Class, for some good reasons
1. Wanted a paging feature ( to be able to jump a particular slide/step in the carousel).
2. Wanted freedom with placement of the LEFT and RIGHT buttons/links , where ever I please.
3. More control over the Slide Steps.

I did manage to create a new Carousel , with the above features …as below … Feel free to suggest any modifications you would require!!!

My Example looks like this…[View Demo]

View Demo | Download Mootools Carousel With Paging Version 1.0 (Downloaded 1916 times)

1. Carousel Paging

You can easily add the paging to your carousel, simply by setting the paging flag, which is last parater passed while creating the instance of the MooCarousel to true( want paging) or false( donot wanting paging).

var carousel1 = new MooCarousel(‘carousel1_wrapper’,'carousel1_items_container’, ‘carousel1_moveleft’, ‘carousel1_moveright’, c_ns,c_sss, true); //ns= number of slides , sss = slide step size

And ofcourse you can change the look-n-feel of these paging achors as you please by modifying their CSS.

.carousel_paging {text-align:right; margin:5px 10px 0 0;}
.carousel_paging .current, .carousel_paging .page{ outline:none; width:15px; height:15px; line-height:15px; text-align:center; display:block; float:left; background:#D8D8EB; margin:0 1px 0 0; text-decoration:none;}

.carousel_paging a:hover, .carousel_paging .current{background:#4D4D9B; color:#ffffff;}

Well! there is a small issue though, The paging anchors if set, then it will get generated always after the Carousel component. I wanted to make it dynamic as well, but then just to keep the Script for blowing out of proportions, I decided to skip it.
But you know a little Javascript , you could easily modify the paging generation code in the MooCarousel class to please your needs.

2. Customising the Left & Right Icons

You can change the PLACEMENT, IMAGES or any displat property of the Left and Right Buttons simply by playing around with the CSS. to be able to change the placements of the Left and Right buttoms was the actual reason for me to right my our Carousel Class.
Since this MooCarousel Class, accepts the id’s of these buttons, you can actually place these buttons anywhere on the page, if you please… it does not have to be in the element hierarchy, as in my example.

var carousel1 = new MooCarousel(‘carousel1_wrapper’, ‘carousel1_items_container’,‘carousel1_moveleft’, ‘carousel1_moveright’,c_ns,c_sss,true);

CSS
.carousel_container_l, .carousel_container_r{margin:50px 0 0 0 ; position: relative;width: 23px;height:20px; float:left; cursor:pointer; }

.carousel_container_r{background-position: 0 -38px; }

.carousel_container_l{background-position: 0 -58px; }

3. Customising Slide Steps

WHAT DO I MEAN MY CUSTOMISING SLIDE STEPS?
Most Carousels slide the full with of the visible window. So say you had four items (like in my sample above), it will slide all the four items. With this Carousel Component, You pass the number of slides and the step size of your choice.

var carousel1 = new MooCarousel(‘carousel1_wrapper’, ‘carousel1_items_container’, ‘carousel1_moveleft’, ‘carousel1_moveright’, c_ns,c_sss, true);
c_ns= number of slides , c_sss = slide step size

Also, in my example1 I have calcuted the slide step size, based on logic where , I know number of items , width on each item and the margins that have given after each item in my CSS.

/*For Carousal 1 */

var c1_w = 92; // Carousal Item Width

var c1_n = 10; // Total Number of Comparision Carousal Items

var c1_pp = 4 // Number of Comparision Carousal Items perpage

var c1_marginFactor = 51;

var c1_sss = c1_w * c1_pp ; //sss = slide step size

var c1_ns = parseInt(((c1_w * c1_n)/c1_sss) + .5); //ns= number of slides

c1_sss += c1_marginFactor ; //sss = slide step size , 51 for margins

Requirements: Mootools 1.2

View Demo | Download Mootools Carousel With Paging Version 1.0 (Downloaded 1916 times)