Javascript

January 21st 2010 // JavaScript // Permalink

jQuery UI: Add Close button to dynamically added tabs

When working with jQuery UI tabs it is really easy to dynamically add tabs. You just use UI's "add" method as specified in the documentation: .tabs( 'add' , url , label , [index] ). But there is no method for dynamically adding a close button so the tabs can be removed. Here is a quick little script I wrote to do just that.

$(function() {
		//DECLARE FUNCTION: removetab
		var removetab = function(tabselector, index) {
			$(".removetab").click(function(){
				$(tabselector).tabs('remove',index);
			});
		 };

		//create tabs
		$("#tabs").tabs({
		   add: function(event, ui) { 
		   		//select newely opened tab
				$(this).tabs('select',ui.index);
				//load function to close tab
				removetab($(this), ui.index);
		   },
		   show: function(event, ui) { 
		   		//load function to close selected tabs
				removetab($(this), ui.index);
		   }
		});
		
		//load new tab
		$(".addtab").click(function(){
			var href=$(this).attr("href");
			var title=$(this).attr("title");
			$("#tabs").tabs( 'add' , href , title+'  ');
			return false;
		});

	});

Usage is simple. Just add class ".addtab" to the links you want opened in a tab, and make sure the link has "title" attribute set as it is used for the tab label.

Add Tab

Here is an example:

Add Tab

Improvements

To avoid adding of duplicate tabs. a function should be added that checks if a specific tab was already added. It should be easy to do. I'll just need to find time to do it.

Update: 02/26/2010

If you don't want to use jQuery UI, but would like to achieve similar effect, visit JankoAtWarpSpeed.com. 

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December 3rd 2009 // JavaScript // Permalink

Progressive Enhancement: Anchor Links to Side Tabs

Here is an example of progressive enhancement technique using jQuery to turn anchor links into side tabs.

Anchor Links Example

Assumption here is that the links are inside an unordered list with ID "services" services assigned to it.

    
Donec arcu est

    
Sed at sem lacus

    
Proin non turpis urna

    
Vestibulum non ipsum orci

    
Nullam cursus ullamcorper

    
Lorem ipsum dolor sit amet

Named anchord are inside a div element with class "item" assigned to it.

 ....text.... 
 ....text.... 
 ....text.... 
 ....text.... 
 ....text.... 
 ....text.... 

jQuery code

Here is a summary of what jQuery will do to the DOM:

1. Append styles
2. Add wrapper div and place all items inside it
3. Highlight and show the first item
4. Add click event to handle navigation from item to item

See comments below for more details.

$(document).ready(function(){
	//page settings
	var navcontainer = "#services";		//Add to the UL conaining the links
	var itemcontainer = ".item";		//Add to the DIV around each section
	var itemwrap = "item_wrap";			//A DIV element with this ID will be wrapped around all items
	var selecteditem = "selecteditem"; //class assigned to the currently selected link
	
	/*****STYLES BLOCK*****/
	// Styles can also be defined in a separate CSS file. if you do so comment out or delete styles block 
	var styles = '<style>'+
	'#'+itemwrap+' {background: #e8e8e8; padding: 10px 15px 15px 15px; float: left; width: 400px; }'+
	navcontainer+' {float:left;font-size:12px;margin:10px 0 0;padding:0;width:250px;list-style: none;}'+
	navcontainer+' li{border-bottom:1px solid #E8E8E8;}'+
	navcontainer+' li a{display:block; color:#3333CC; text-decoration:none;line-height:12px;padding:8px 0px 8px 10px;outline:0;}'+
	navcontainer+' .'+selecteditem+'{background: #e8e8e8;}'+
	'</style>';
	//add styles to the head
	$("head").append(styles);
	/*****END STYLES BLOCK*****/
	
	//create item_wrap div
	$(itemcontainer+":first").before('<div id="'+itemwrap+'"> </div>'); 
	//add items to wrap
	$(itemcontainer).appendTo("#"+itemwrap);
	//show only first item
	$(itemcontainer).not(":first").hide();
	//mark first link as selected
	$(navcontainer+" li:first").addClass(selecteditem);
	//services click
	$(navcontainer+" a").click(function(){
		$(navcontainer+" li").removeClass(selecteditem);
		$(this).parent("li").addClass(selecteditem);
		var li_index = $(navcontainer+" a").index(this);
		$(itemcontainer).hide().eq(li_index).slideToggle("fast");
		return false;		
	});
});

Here is an example.

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November 25th 2009 // JavaScript // Permalink

Progressive enhancement: Accordion Style FAQ's with jQuery

Condense a lengthy FAQ page with accordion style navigation, making your answers only appear when the questions of interest are clicked.

To use it:

1. Add this script to the FAQ page
2. Assign class "question" to every question
3. Assign class "answer" to every answer

$(document).ready(function(){
		//just some regular style sheets. change them as you see fit
		var styling =".question{font-size:14px; font-weight:bold; cursor:pointer;}" +
					  ".answer{display:block;}" +
					  ".opened{color:#006699;}" +
					  ".closed{color:#009966;}";		
		//attach style to the page
		var style = document.createElement("style");
        style.type = "text/css";
        try {
            style.appendChild( document.createTextNode(styling) );
        } catch (e) {
            if ( style.styleSheet ) {
                style.styleSheet.cssText = styling;
            }
        }
        document.body.appendChild( style );
		//style all questions as closed
		$(".question").addClass("closed"); 
		//make sure first question is styled as open
	        $(".question:first").removeClass("closed").addClass("opened"); 
		$(".answer").hide(); //hide answers
		$(".answer:first").show(); //show first answer
		//question click
		$(".question").click(function() {
			$(".answer").slideUp("fast");
			$(".question").removeClass("opened").addClass("closed");
	
			if ($(this).next(".answer").is(":hidden")) {
				$(this).next(".answer").slideDown("fast");
				$(this).removeClass("closed").addClass("opened");
			} 			   
		});
});

Example HTML

Lorem ipsum dolor sit amet, consectetur adipiscing elit?
Ed ligula libero, dictum at dapibus non, egestas a massa. Cras sit amet dolor felis. Morbi gravida vulputate condimentum. Nam ut nisl nibh.

Nulla a placerat leo. Proin ut hendrerit tellus?
Sed consequat turpis ac justo tristique elementum. Maecenas vitae mi dui. Maecenas nulla ligula, condimentum vitae posuere nec, fringilla eu sapien.

Donec faucibus tristique quam ac eleifend?
Nullam malesuada malesuada tempus. Phasellus posuere imperdiet dignissim. Nam id arcu erat, vel volutpat est. Maecenas ullamcorper interdum lacus vel tincidunt. Quisque egestas turpis et orci rhoncus posuere. Integer vehicula gravida interdum. 

Working Example

 

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November 23rd 2009 // JavaScript // Permalink

jQuery UI: Highlight multiple dates in jQuery datepicker

The events are stored as UNIX timestamps in a MySQL table. We'll be getting those events from the database via AJAX and highlight them in the jQuery UI datepicker widget.

HTML

Javascript

$.ajax({
  url: "dates.php",
  data: "action=showdates&id=1",
  dataType: "json",
  success: function(calendarEvents){ 
           $(".calendarwidget'").datepicker({

           // [rows, columns] if you want to display multiple calendars.                         
           numberOfMonths: [1, 1],
           showCurrentAtPos: 0,
           beforeShowDay: function (date){
                          for (i = 0; i < calendarEvents.length; i++) {
                              if (date.getMonth() == calendarEvents[i][0] - 1 
                              && date.getDate() == calendarEvents[i][1]
                              && date.getFullYear() == calendarEvents[i][2]) {
                              //[disable/enable, class for styling appearance, tool tip]
                              return [false,"ui-state-active","Event Name"]; 
                              }
                           }
                           return [true, ""];//enable all other days
                        }
           });
           }
         });

PHP

Here is our AJAX service. Assumption here is that we are getting the date from a UNIX timestamp stored in a MySQL table.

$action = $_REQUEST['action'];
$id = $_REQUEST['id'];

switch ($action){
case 'showdates':
$qry = "SELECT * FROM event_table WHERE eventid = '".$id."'";
        $result = mysql_query($qry) or die ("Error in query: $qry. " . mysql_error());
        echo '[';
        do{
            if($row->eventid != ''){//makes sure no blanks are returned
                 //this assumes that "eventdate" is UNIX timestamp
                $converteddate =  date("m,d,Y",$row->eventdate);
                $dates .= '['.$converteddate.'],';
            }
        }while($row = mysql_fetch_object($result));
        $dates =rtrim($dates, ",");
        echo $dates;
        echo ']';
break;
}

Resources

jQuery UI datepicker
http://jqueryui.com/demos/datepicker/

jQuery AJAX
http://docs.jquery.com/Ajax

PHP Date Manual
http://php.net/manual/en/function.date.php

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November 17th 2009 // JavaScript // Permalink

Progressive enhancement: AJAX navigation menu with jQuery

Progressive enhancement allows everyone to access the basic content and functionality of a given web site using any browser or Internet connection, while also providing those with a more advanced browsers an enhanced version of the site.

Here is an example on how to enhance a starndard navigation bar with AJAX.

Scenario

Let's assume that #header, #navigation and #footer are same on every page  and #mainconent, and #sidebar inside the #content are changing on every page.

Problem
The site will have a music player that clients can choose to use while browsing the site. And if they do, we don't want the music to be interupted as they move from page to page.

Solution
Use unobtrusive javascript and AJAX to load content and update the URL using hash in case someone wants to bookmark loaded content.

 

sdf

Javascript/jQuery

We'll use jQuery to bind a click event to the navigation links and use load function to load contents of the clicked page.

Html navigation

     
< a href="index.html">Home< /a >

     
< a href="about.html">About< /a >

     
< a href="service.html">Service< /a >

     
< a href="contact.html">Home< /a >

Javascript

//FIRST: We'll check if the URL has a hash (was bookmarked) and redirect the user to appropriate page
	 if(window.location.hash!=""){
		var hashpage = window.location.hash.split("#");
		window.location.pathname = hashpage[1];	 
	 }

jQuery

 //bind click event to the navigation links
	 $("#navigation a").unbind("click").click(function(){
		//get href attribute 	
		var page = $(this).attr("href");
		//load all children of the #content div of the clicked page 
		$("#content").load(page+" #content > *");
		//append hash to the url for bookmarking
		window.location.hash="#"+page;
		//cancel browser default so the page doesn't reload
		return false;
	
	 });

Putting it all together

$(document).ready(function(){

	 if(window.location.hash!=""){
		var hashpage = window.location.hash.split("#");
		window.location.pathname = hashpage[1];	 
	 }
	 //navigation
	 $("#navigation a").unbind("click").click(function(){
		//get href attribute 	
		var page = $(this).attr("href");
		//load contents of all children of the #content div
  		$("#content").load(page+" #content > *");
		//append hash to the url for bookmarking
		window.location.hash="#"+page;
		//cancel browser default so the page doesn't reload
		return false;
	
	 });
});

 

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November 17th 2009 // JavaScript // Permalink

Create simple cross-browser textarea editor

This tutorial will help you create simple cross-browser textarea editor you can use on any of your HTML forms. View the sample.

The main DHTML methods used in this cross-browser textarea editor are:

• execCommand.
  This method  executes a command on the current document, current selection, or the given range.
• getElementById
  Returns a reference to the first object with the specified value of the ID attribute.

Commands used to specify an action to take on the given object:

• Bold
  Toggles the current selection between bold and nonbold.
• Underline
  Toggles the current selection between underlined and not underlined.
• Italic
  Toggles the current selection between italic and nonitalic.
• JustifyCenter
  Centers the format block in which the current selection is located.
• JustifyLeft
  Left-justifies the format block in which the current selection is located.
• JustifyRight
  Right-justifies the format block in which the current selection is located.
• Indent
  Increases the indent of the selected text by one indentation increment.
• Outdent
  Decreases by one increment the indentation of the format block in which the current selection is located.
• Undo
  Undo the step
• Redo
  Redo the step

Main DHTML properties used:

• innerHTML
  Sets or retrieves the HTML between the start and end tags of the object.
• designMode
  Sets or retrieves a value that indicates whether the document can be edited.

Download the button images here.

CSS File

.editorbuttons {
	list-style: none;
	margin: 0px;
	padding: 0px;
}
.editorbuttons li {
	float: left;
}
.editorbuttons li img {
	border:none;
}
.editorbody{clear:both; float:none;}

 

HTML File

 

 

 

 

 

 

 

 

 

 

Shift+Enter for single line spacing


< script language= "JavaScript" type= "text/javascript"  >

< /script >
< script language= "JavaScript" type= "text/javascript" >
    //this calles displayEditor function. Parametars are (textarea name, ,default text, textarea  width, textarea  height)
    displayEditor('content', 'Default Text', 600, 300);	
//-->
< /script >

 

JavaScript File

See comments for details

//First initiate some variables

var isEditable= false;
var isIE;
var isGecko;
var isSafari;
var isKonqueror;
var browser = navigator.userAgent.toLowerCase();

function initiateEditor() {
 //check what browser is in use

 isIE = ((browser.indexOf("msie") != -1) && (browser.indexOf("opera") == -1) && (browser.indexOf("webtv") == -1)); 
 isGecko = (browser.indexOf("gecko") != -1);
 isSafari = (browser.indexOf("safari") != -1);
 isKonqueror = (browser.indexOf("konqueror") != -1);
 
 //enable designMode if the browser is not safari or konqueror.
 if (document.getElementById && document.designMode && !isSafari && !isKonqueror) {
   isEditable= true;
 }
}
//Javascript function dislpayEditor will create the textarea. 

function displayEditor(editor, html, width, height) {
   if(isEditable){
       document.writeln('');
//create a hidden field that will hold everything that is typed in the textarea
       document.writeln('');
//assign html (textarea value) to hiddeneditor 
      document.getElementById('hidden' + editor).value = html;
//call function designer
      designer(editor, html);
   }else{
     document.writeln('< textarea name="' + editor + '" id="' + editor + '" cols="39" rows="10">' + html + '');
   }
}

//this is designer function that enables designMode and writes defalut text to the text area
function designer(editor, html) {
     var mainContent= "< html id=" + editor + ">< head >< /head >< body >" + html + "< /body >" ;
//assign the frame(textarea) to the edit variable using that frames id
     var edit = document.getElementById(editor).contentWindow.document;
//write the content to the textarea
      edit.write(mainContent);
	  edit.close();
//enable the designMode	
      edit.designMode =  "On" ;
	  document.getElementById(editor).contentDocument.designMode = "on";
}

//To execute command we will use javascript function editorCommand. 
function editorCommand(editor, command, option) {
// first we assign the content of the textarea to the variable mainField
    var mainField;
	mainField = document.getElementById(editor).contentWindow;
 // then we will use execCommand to execute the option on the textarea making sure the textarea stays in focus
   try {
          mainField.focus();
          mainField.document.execCommand(command, false, option);
          mainField.focus();
    } catch (e) { }
}

function updateEditor(editor) {
	if (!isEditable) return;
//assign the value of the textarea to the hidden field. 
	var hiddenField = document.getElementById('hidden' + editor);
	if (hiddenField.value == null) hiddenField.value = "";
		hiddenField.value = document.getElementById(editor).contentWindow.document.body.innerHTML;
}

PHP File

Most important part of the PHP code is the phpSafe function. This function makes sure that quotes are displayed appropriatly. See comments for details.

 

// from the form we are getting the hidden field value and sending it to the phpSafe function
$hiddencontent = phpSafe($_REQUEST['hiddencontent']);
function phpSafe($strText) {
 //removes backslash created by php from the string
    $tmpString = $strText;
    $tmpString = str_replace(chr(92), "", $tmpString); 
    return $tmpString;
}
echo $hiddencontent;

Save all files in the same folder and upload to your server. Play with the code and try adding more functionality or buttons. Here are some helpfull resources:

• MSDN library
• Mozilla Editor

 

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November 15th 2009 // JavaScript // Permalink

Create a Scrolling Text Box using JavaScript

This can be easily done using jQuery or similar JavaScript libraries. But sometimes you may choose not to load the whole library for a simple task like scrolling text.

Javascript scrolling text function

Create a javascript function and place it either inside the   element using < script > tag, or inside a separate javascript file.

//Define a variable (pos) to store the current scroll position. 
var pos = 100;

function Scroll(){
    //get the id of the scrolling text box. 
    obj=document.getElementById('scrolltextlayer');
    //subtract 1 from pos and check pos value using offsetHeight, which retrieves the height of the object relative to the layout. 
    pos -=1;
    
    if(pos < 0 - obj.offsetHeight+130) return;
    //set a new height value using JavaScript style object.     
    obj.style.top=pos;
    //finally the function calls itself using a timeout..
    window.setTimeout( "Scroll();" ,  30);
}

HTML

HTML is pretty simple:

1. Create outer div that will act as a "frame"
2. Create inner (scrolling) div

 OUTER DIV 

 INNER DIV 


Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Cras hendrerit mauris eget nunc. Proin dapibus eros in quam. Nunc nulla nunc, nonummy auctor, scelerisque non, cursus et, leo. 
 Nullam egestas nulla feugiat orci. Integer lorem sapien, ullamcorper dapibus, cursus eu, sagittis vel, dolor. Mauris tincidunt, magna in congue bibendum, sem quam tincidunt tortor, in consectetuer turpis odio a libero. 

 Link to scroll again 
Scroll again



 END INNER DIV 

 END OUTER DIV 

Implementation

Just call the function from "onload" attribute inside the   tag.

< body onLoad="Scroll();">

 

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November 9th 2009 // JavaScript // Permalink

Dynamicaly generate a Web Safe Color palette with JavaScript

Generating web safe color palette can be easily done using JavaScript. Web safe palette contains 256 colors that we can come up with by mixing some basic colors.

Here is the code

//first lets start with the table that will contain the palette
t='';

//next we define the array of basic colors including black, white and gray
c=new Array('00','CC','33','66','99','FF');

//now we will iterate through colors. Notice how number 6 corresponds to number of items in the array c
for(i=0;i<6;i++){
 for(j=0;j<6;j++){

 // each row will have 6 colors
  t +='';
   for(k=0;k<6;k++){

    //this creates hex code for each color
    l=c[i]+c[j]+c[k];

    //now lets create table cell for each color
    t+='';
   }
  t +='';
 }
}

//now let's display the palette 
document.write(t+'
#'+l+'
');

That's it. Pretty simple!

Here is the example

 

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November 9th 2009 // JavaScript // Permalink

Javascript location Object explained

Javascript scripts can manipulate the Web pages and it's contents using a hierarchy of parent and child objects called the DOM (Document Object Model). Those objects are organized into a tree-like structure and represent all of the components of a web page. Objects in the DOM have properties, which describe the Web page, and methods, which allow you to work with parts of the Web page.The window object is the parent object for all the objects. One of the objects under window is the location object.

Location Object

Location object stores information about the current URL in the window. For example this statement loads emirplicanic.com website in the current browser window.

window.location.href = "http://www.emirplicanic.com"; 

The href property contains the entire URL, but you can use various properties to access portions of the URL.

Properties

Let's take following URL apart: http://www.emirplicanic.com:80/55.php?id=12#headline 

• location.protocol would give us the protocol part of the URL (http: )
• location.hostname would give us host name of the URL (i.e. www.emirplicanic.com)
• location.port would give us the port number of the URL (80)
• location.pathname would give us the filename part of the URL (55.php)
• location.search would give us the query part (if any) of the URL (id=12)
• location.hash would give us the anchor name used in the URL (#headline)

Methods

The location object has two methods:

location.reload()- reloads the current page. It acts the same as the browser reload button. You can include a parameter true to ignore the browser's cache and force a reload whether the document has changed or not.

location.replace()- replaces the current location with a new one. It's pretty much the same as changing the location properties, except that it doesn't affect the browser's history. So, if you use replace method you can't use browser's back button to go to previous location. This is mostly used for temporary pages or splash screens.

Example

Let's say you are using an AJAX script to load a page based on the search query in the URL. You could create a function:

function getSearch()
{
    return document.location.search;
}

or just use document.location.search somewhere within the function that handles AJAX calls.

If you want to pass a url to the getSearch function modify the code like this:

function getSearch(url)
{
    return url.location.search;
}

and call it like this:

Pass a URL

There you have it a quick overview of the DOM's location object.