Coding Cheatsheets - Learn to Code

Populating city Dropdown based on Country Selecting by using jQuery and Ajax. Step 1: Load the jquery library <script type="text/javascript" src="http://code.jquery.com/jquery.js"></script> Html view: <div> <label>Country:</label> <select class="country"> <option>Select</option> <option value="usa">United States</option> <option value="india">India</option> <option value="uk">United Kingdom</option> </select> </div> <div id="response">     <!--Response will be inserted here--> </div> Step 2: Call jQuery change event and fetch the ajax <script type="text/javascript"> $(document).ready(function(){     $("select.country").change(function(){         var selectedCountry = $(".country option:selected").val();         $.ajax({          ...

PHP Magic Function The " magic " methods are ones with special names, starting with two underscores, which denote methods which will be triggered in response to particular PHP events. magic functions will never directly be called by the programmer – actually, PHP will call the function ‘behind the scenes’. List of List of Magic Methods in PHP __construct:  This magic methods is called when someone create object of your class. Usually this is used for creating constructor in php5. __destruct:  This magic method is called when object of your class is unset. This is just opposite of __construct. __get:  This method called when your object attempt to read property or variable of the class which is inaccessible or unavailable. __set:  This method called when object of your class attempts to set value of the property which is really inaccessible or unavailable in your class. __isset:   This magic methods trigger when isset() function is applied on any p...

Final method: A final method is a method that cannot be overridden. To declare a method as final, you need to prefix the function name with the ‘final’ keyword. eg: class Teacher {     final public function attendance() {       echo "Teacher attendance called";    } } class Student extends Teacher {    //this will cause Compile error    public function attendance() {        echo "Student attendance called";    } } $st = new Student(); $st->attendance(); Results in Fatal error: Cannot override final method Teacher::attendance() final class: A final class is a class that cannot be extended. To declare a class as final, you need to prefix the ‘class’ keyword with ‘final’. Example below. final class Teacher {    public function attendance() {       echo "Teacher attendance called";    } } //this will cause Compile error class Studen...

The UNION set operator is used for combining data from two tables which have columns with the same datatype.When a UNION is performed the data from both tables will be collected in a single column having the same datatype. Rules: The number of columns appears in the corresponding SELECT statements must be equal. The columns appear in  the corresponding positions of each SELECT statement must have the same data type or at least convertible data type. You cannot use the union operator on text and image columns. Notes: Union -- returns with no duplicate rows Union all -- retruns with duplicate rows (No. of rows returned = No. of rows in Query1 + No. of rows in Query 2) Example: Suppose you want to combine data from the  student and teacher tables into a single result set, you can UNION operator as the following query: SELECT studentNumber id, contactLastname name FROM student UNION SELECT teacherNumber id,firstname name FROM teacher Here is the output...

Searching with Ajax pagination Cakephp Step 1 : View File <script> $(document).ready(function(){ $(".pagination a, .header a").on('click',function(){ $('#content').load(unescape($(this).attr("href")),function(){ }); return false;   }); }); </script> <div id="content"> <?php echo $this->Form->create('User',array('type'=>'GET')); echo $this->Form->input('User.name',array('id'=>'name','error'=>array('class'=>'error'),                     'required'=>false,'value'=>@$_GET['data']['User']['name'])); echo $this->Form->input('User.email',array('id'=>'email','error'=>array('class'=>'error'),                     'required'=>false,'value'=>@$_GET['data'...

Cakephp Ajax Pagination Cakephp Ajax pagination works same like normal pagination , the difference is that it load the pages without refreshing Controller index function public function index(){         $this->paginate = array('limit'=>5,'order'=>'User.id desc');   $userDetail = $this->paginate('User'); $this->set('userDetail',$userDetail); if($this->RequestHandler->isAjax()){ // check the type of request $this->layout = ''; $this->autoRender = false; $this->render('index');  // render the same view } } User index view // script to load page by ajax <script> $(document).ready(function(){ $(".pagination a, .header a").on('click',function(){ $('#content').load(unescape($(this).attr("href")),function(){ }); return false;   }); }); </script> <div id="content"> // show the ...

Check All by jQuery Method 1:  $(document).ready(function() {     $('#selectAll').click(function(event) {         if(this.checked) { // check select status             $('.checkbox1').each(function() {                 this.checked = true;  //select all checkboxes with class "checkbox1"                         });         }else{             $('.checkbox1').each(function() {                 this.checked = false; //deselect all checkboxes with class "checkbox1"                                 });               }     });   }); Html <div> <input type="checkbox" id="selectAll"...