AngularJS, HTML5, JavaScript

Using HTML5 LocalStorage with AngularJS

Today , I will talk about LocalStorage Support of HTML5.

We can store named key/value pairs locally, within the client web browser. Like cookies, this data persists even after you navigate away from the web site, close your browser tab, exit your browser, or what have you. Unlike cookies, this data is never transmitted to the remote web server (unless you go out of your way to send it manually). Unlike all previous attempts at providing persistent local storage, it is implemented natively in web browsers, so it is available even when third-party browser plugins are not.

HTML5 STORAGE SUPPORT
IE FIREFOX SAFARI CHROME OPERA IPHONE ANDROID
8.0+ 3.5+ 4.0+ 4.0+ 10.5+ 2.0+ 2.0+

Based on different browsers , we can get 2 MB to 5MB (even more) space in LocalStorage . To get more idea on space check out this link …

BY the below code , we can check our browser supports LocalStorage or Not !

function supports_html5_storage() {
    try {
        return 'localStorage' in window && window['localStorage'] !== null;
    } catch (e) {
        return false;
    }
}

Also we can use Modernizr to check this .

if (Modernizr.localstorage) {
    // window.localStorage is available!
} else {
    // no native support for HTML5 storage :(
}

Lets develop a simple LocalStorage Cache framework with AngularJS .

For this , am gonna create an AngularJS Factory Service to communicate with the HTML5 LocalStorage .

'use strict';

valApp.factory('storageService', function ($rootScope) {

    return {
        
        get: function (key) {
           return localStorage.getItem(key);
        },

        save: function (key, data) {
           localStorage.setItem(key, JSON.stringify(data));
        },

        remove: function (key) {
            localStorage.removeItem(key);
        },
        
        clearAll : function () {
            localStorage.clear();
        }
    };
});

localStorage keyword in the upper is the core API which is responsible for providing LocalStorage facility .

I have not used this storageService directly in the client .I am gonna use another Mid Layer Factory which will communicate with storageService and client code will call this Mid Layer Factory named cacheService . This is like below :::

'use strict';

valApp.factory('cacheService', function ($http, storageService) {
    
    return {
        
        getData: function (key) {
            return storageService.get(key);
        },

        setData: function (key,data) {
            storageService.save(key, data);
        },
        
        removeData: function (key) {
            storageService.remove(key);
        }
    };
});

You can see , I have injected storageService to cacheService .

Now from my AJs Controller , I will call cacheService’s Function to serve my purpose .

Now below is the example , how you can use this Cache Framework …

In My Controller , I’ve simply injected cacheService and can use all the features of it .

var city = [
                  { Id: 1, Name: 'Dhaka' },
                  { Id: 2, Name: 'Ctg' }
    ];
    cacheService.setData('city', city);

I have used the Mid Layer , if we need any new logic later, we can easily add those to the Mid Layer .

Its easy and awesome , right ?

Cheers 🙂

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AngularJS, JavaScript

AngularJS : Using Promise-Part1

In Modern Web (Web 2.0) , We use so many Asynchronous call in our Web Applications . But sometimes , we need that , A Call is depended on another call .That means – After First Method’s Success CallBack another Method should be called . So if both the call occurs asynchronously , It does not fit my requirement .

So We can use AngularJS Promise to do this kind of things .

Lets see an example .

app.controller('PersonCtrl', ['$scope', '$rootScope', '$http', '$q', 'setting', function($scope, $rootScope, $http, $q, setting) {
    
    $scope.personsFromServer = [
        { Id: 1, Name: 'Shahjada' },
        { Id: 2, Name: 'Talukdar' },
        { Id: 3, Name: 'Masoom' }
    ];

    var getPersonPromise = function() {
        var deferred = $q.defer();
        deferred.resolve($scope.personsFromServer);
        return deferred.promise;
    };

    getPersonPromise().then(function(persons) {
        $scope.persons = persons;
        $scope.personId = persons[0].Id;
    }, function (reason) {
        alert('Failed: ' + reason);
    });
    
}]);

I am mocking PersonsFromServer Data in my example (Suppose this is gonna come from Server By an asynchronous call) .Now I am gonna populate a DropDown after successfully returning the data , and am selecting the first Person as selected Item in DropDown .

<div ng-controller="PersonCtrl">
        <select id="Person"
            ng-model="personId"
            ng-options="p.Id as p.Name for p in persons"
            required>
        </select>
    </div>

The Deferred API

A new instance of deferred is constructed by calling $q.defer().

The purpose of the deferred object is to expose the associated Promise instance as well as APIs that can be used for signaling the successful or unsuccessful completion of the task.

The Promise API

A new promise instance is created when a deferred instance is created and can be retrieved by calling deferred.promise.

The purpose of the promise object is to allow for interested parties to get access to the result of the deferred task when it completes.

Hope you got the idea .

Thanks .
In Part2 , I will show Calling API from Server with Resource and of course with Promise .

Cheers

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AngularJS, ASP.Net, HTML5, HTTP & HTTPS, JavaScript, jQuery, jQuery AJAX

How HTTPS Works : Part1

I wanted to write a basic article on How HTTPS works , then I got this below article , so am gonna share his Article here . Hope , all will enjoy this one .

http://blog.hartleybrody.com/https-certificates/

And I will write more on HTTPS in Part2,3… etc …

Cheers 🙂

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ASP.Net, C#, JavaScript, jQuery, jQuery AJAX

jQuery Ajax in Action with ASP.Net aspx Page

Most of the time , We call our custom WebServices/REST Services/Third Party REST APIs from any jQuery AJAX based HTTP Verb . But we can also call direct ASP.Net Form Page( which is aspx page ) using jQuery AJAX .

Here is how we can call ASPX page from another ASPX page’s AJAX Method.

For this example , I have used two ASPX page –

1.AjaxCheckPage.aspx ::: From this page I am gonna call another ASPX Page
2.jQueryAjaxData.aspx ::: This Page will be called by jQuery AJAX

HTML Markup of my AjaxCheckPage.aspx is like below :

<input type="button" id="ajaxButton" value="Load Data using jQuery Ajax" />   

     <div id="divResult"></div>

Ajax calling code of this Page is —

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

        $("#ajaxButton").click(function () {

            $.ajax({

                type: "POST",
                url: "jQueryAjaxData.aspx",
                data: "a=2&b=3",
                success: function (data) {
                    $("#divResult").text(data);
                }

            });

        });
    
    </script>

So Now , am doing like – If any Data comes from jQueryAjaxData.aspx , that means after successful , am binding the data to the DIV :

Now lets go another Page jQueryAjaxData.aspx from which the Data is gonna come .

protected void Page_Load(object sender, EventArgs e)
        {
            if (Request.Form["a"] != null && Request.Form["b"] != null)
            {
                int a = int.Parse(Request.Form["a"]);
                int b = int.Parse(Request.Form["b"]);
                int sum = a + b;
                
                Response.Write("The Sum is : " + sum);
            }
        }

jQuery Ajax in Action with ASP.Net aspx Page

jQuery Ajax in Action with ASP.Net aspx Page

So you can see , when I click the button then It request a POST to jQueryAjaxData.aspx page and am also passing Form Data as you can see it inside the picture above .

So , this is how , we can call ASPX page from jQuery AJAX POST .

Cheers 🙂

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AngularJS, HTML5, JavaScript

HTML5 DragDrop -Part 1 : With HTML5 , JavaScript

In The Current World of Web , Drag and Drop on the Browser has been a required Feature for many People . And YES Its much easy with HTML5 Drap&Drop . In my Example , I used HTML5 DragDrop with the help of jQuery and JavaScript .

My My App has been developed on AngularJS framework.

DragDrop

Here is my HTML Code :::

<body>
        
        <h1 style="color: blueviolet">Drag a number and Drop that to Recycle Bin</h1><br/>

        <div ng-controller="IndexCtrl">
            <ul class="unstyled">
                <li ng-repeat="tile in tiles">
                    <img id="{{$index}}" height="50" width="50" draggable="true" ondragstart="drag(event)" src="{{tile.imgUrl}}" />
                    <br /><br />
                </li>
            </ul>

            <div id="dropHere" ondrop="drop(event)" ondragover="allowDrop(event)" style="margin-top: 150px" class="bottom">
                <img height="100" width="105" src="Images/RecycleBin.png" />
            </div>
        </div>
    </body>

This is the Source of my Numbers which lies on my AngularJS Controller’s Scope .

$scope.tiles = [
        { text: '1', imgUrl: setting.imageUrl + 'orderedList1.png' },
        { text: '2', imgUrl: setting.imageUrl + 'orderedList2.png' },
        { text: '3', imgUrl: setting.imageUrl + 'orderedList3.png' },
        { text: '4', imgUrl: setting.imageUrl + 'orderedList4.png' },
        { text: '5', imgUrl: setting.imageUrl + 'orderedList5.png' }
    ];

And The Implementations of the HTML5 DragDrop Events are as follows :::

function drag(ev) {
    ev.dataTransfer.setData("Text", ev.target.id);
}

function allowDrop(ev) {
    ev.preventDefault();
}

function drop(ev) {
    ev.preventDefault();
    var data = ev.dataTransfer.getData("Text");
    var nodeToRemove = $("#" + data)[0];
    ev.target.appendChild(nodeToRemove);
}

After Dragging each Number , We can see in the DOM that every Item is going inside the Recycle Bin Node like below :

DragDOM

But If our Site needs massive this kind of thing , The DOM will become more heavy , so if our Requirements does not need those Dropped Items in the future , We can just remove the Item , by this our DOM will have less weight .

ev.target.removeChild(nodeToRemove);

In Part 2 of this Article, Drag&Drop will be done by AngularJS Directive .

Cheers

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AngularJS, HTML5

AngularJS Routing : Part 2 – make # (Hash) invisible from URL in SPA

Before reading this Article , Please check out AngularJS Routing : Part 1 Create a Single Page Application (SPA) first .

Every AngularJS Dev likes the way that the routing of AngularJS works . It uses # (Hash) in the URL like below –

###

But Its not very readable for Public User , non Tech people , mass people of the world , so its better to make the # invisible from the URL . And Yes, Its real EASY !!!

First Set the Html5Mode to true in LocationProvider . Now the app.js file will be like :::

spaApp.config(function ($routeProvider, $locationProvider) {

    $locationProvider.html5Mode(true);

    $routeProvider.when("/", { templateUrl: "/partials/home.html" }).
                   when("/profile", { templateUrl: "/partials/profile.html" }).
                   when("/contact", { templateUrl: "/partials/contact.html" }).
                   otherwise({ redirectTo: '/' });

});

And my index.html code will be like below now :::

<tr>
                <td>
                    <a href="/">Home <i class="icon-arrow-down"></i></a>
                </td>
                <td>
                    <a href="/profile">Profile <i class="icon-arrow-down"></i></a>
                </td>
                <td>
                    <a href="/contact">Contact <i class="icon-arrow-down"></i></a>
                </td>
            </tr>

My SPA Site is now without that # …

#less

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AngularJS, HTML5

AngularJS Routing : Part 1 – Create a Single Page Application (SPA)

A single-page application (SPA), also known as single-page interface (SPI), is a web application or web site that fits on a single web page with the goal of providing a more fluid user experience akin to a desktop application.

And developing SPA has been so easier with AngularJS Route Service .

Application routes in Angular are declared via the $routeProvider, which is the provider of the $route service. This service makes it easy to wire together controllers, view templates, and the current URL location in the browser. Using this feature we can implement deep linking, which lets us utilize the browser’s history (back and forward navigation) and bookmarks.

I am gonna show how to build simple SPA within 1 hour 🙂

Here is my index.html Code ::: (ASP.Net developers can think this index.html as MasterPage)

<!DOCTYPE html>
<html ng-app="SpaApp">
<head>
    <meta charset="utf-8" />
    <title>My SPA Site</title>
    <script src="lib/angular.min.js" type="text/javascript"></script>    
    <script src="app/app.js" type="text/javascript"></script>
    <link href="styles/bootstrap.css" rel="stylesheet" type="text/css" />
</head>
<body>
    <div>
        <a href="/">
            <h1>My SPA Site</h1>
        </a>
        <br />
        <table>
            <tr>
                <td>
                    <a href="/">Home <i class="icon-arrow-down"></i></a>
                </td>
                <td>
                    <a href="#/profile">Profile <i class="icon-arrow-down"></i></a>
                </td>
                <td>
                    <a href="#/contact">Contact <i class="icon-arrow-down"></i></a>
                </td>
            </tr>
        </table>
        <br />
         <div ng-view></div>
    </div>
</body>
</html>

The $route service is usually used in conjunction with the ngView directive. The role of the ngView directive is to include the view template for the current route into the layout template, which makes it a perfect fit for our index.html template.

(This ngView directive can be compared as Main ContentPlaceHolder of ASP.Net , just saying for .Net Devs )

My app.js code is like below :::

var spaApp = angular.module('SpaApp', []);

spaApp.config(function ($routeProvider) {

    $routeProvider.when("/", { templateUrl: "/partials/home.html" }).
                   when("/profile", { templateUrl: "/partials/profile.html" }).
                   when("/contact", { templateUrl: "/partials/contact.html" }).
                   otherwise({ redirectTo: '/' });

});

In this RouteProvider we can define URL and HTML Template .

And For this App , I have 3 Partial Views . The codes of these views are like below :::

home.html
———-

<div>
    <h2>This is Home Page</h2>
</div>

profile.html
————-

<div>
    <h2>This is Profile Page</h2>
</div>

contact.html
————-

<div>
    <h2>This is Contact Page</h2>
</div>

So Here , you are done with the simple SPA Site 🙂

The Site will look like – >

#

To Read Part 2 -> Please Click AngularJS Routing : Part 2 – make # (Hash) invisible from URL in SPA

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