web app dev full

Creating a Web App from Scratch – Part 1 of 8: Basic Idea and Design PUBLISHED NOVEMBER 23, 2009 BY CHRIS COYIER

Today we begin Part 1 of an 8-Part series on building a web application from absolute scratch to a complete product. I am going to kick things off by introducing the idea, and then I will be handling the design, UI, and general front-end stuff. We are going to be going back and forth from here over to my friend Jason Lengstorf's site Copter Labs. Jason will be handling the back-end stuff like application planning and database stuff. At the end of the week, we'll unleash the actual working application for you. Here is the plan: ALL SERIES NAVIGATION

        

Part 1 - Planning the App: Basic Idea and Design Part 2 - Planning the App: Database Architecture and Development Approach Part 3 - Designing the App: Workflow Map and Photoshop Design Part 4 - Designing the App: HTML and CSS Part 5 - Developing the App: User Interaction Part 6 - Developing the App: Adding AJAX Interactivity Part 7 - Developing the App: List Interaction Part 8 - Security & The Future

And finally.... the application!

Colored Lists

It's Easy, Right? What we're going to create is a "list app". The idea being focused on simplicity and usefulness. Sign up for an account, and get started making a list in just a few seconds. Sounds easy right? Even the PHP dabblers out there probably could throw something like this together fairly quickly, right? Well the fact is, no, it's not that easy. First of all, it needs to work and it needs to work well. That means good back end code that does what it's supposed to do and well. That means a good UI that is intuitive, helpful, and pleasurable to use. It means keeping the app secure and users data private. None of these things is trivial. Through this whole 8-part series, we are going to create an app that hopefully does all these things pretty well. We aren't out to tell you this is the greatest app ever made, but rather, we are going to use this app as a walk-through journey of the app creating process and hopefully do as many smart things as we can along the way.

The Big Idea This "list app" is going to be called Colored Lists. Lists (in real life), can be for anything: a to-do list, a grocery list, things to bring camping list... As you finish things, you cross them off. Things on a list may be of different relative importance as well. This makes paper lists potentially messy and inefficient. With a list on a computer, we can make crossing off items just a click and we can make rearranging them a matter of drag and drop. For dealing with relative importance, we can use colorization, which could also be used for things like grouping. Computers, and the web, are a perfect place for lists.

Sketch It Out No need to get fancy right away. Here is a very rudimentary sketch of what the app might look like:

Looks like a list to me. Each list item is a long rectangle, because the big idea here is to colorize each list item, so putting them inside a colored box makes sense. There are some interactive elements to the left and right of each list item. Those are going to be for accomplishing the basic things we intent people to be able to do with their colored list. Lets take a closer look.

Early UI Planning

We don't necessarily want to be talking about specific technologies at this point, but we should be thinking about how the UI will operate, so we can make choices about technology that can accommodate our UI desires.

   

Click-to-edit Drag and drop Two-click delete Automatic saving (after any action)

All this stuff basically adds up to a whole bunch of AJAX. We don't want to load special screens to do relatively trivial tasks like deleting a list item. That stuff should happen seamlessly, smoothly and with proper feedback in response to mouse clicks without page refreshes. In a sense, we are creating a one-page app, where the majority of interaction with this app happens on a single page. This is certainly by design, and not trying to adhere to any particular fad. Lists are easy and quick, that's why are useful. If this app is complicated, it's usefulness is diminished and nobody will use it.

The Screens Just doing some quick brainstorming of the idea so far, we can come up with quite a number of "screens", or states the application can be in.



Homepage

  

Logged out = Intro/Sales Page Logged in = Your list Log in page

   

Settings page Lost password page Account activation page Emails Yep, even emails should be considered a part of the "screens", as they are a vital part of the process and interaction with an app.

"Features" People love "features". Things that your app has that other apps don't have, or that yours does better. This is just as much for marketing as it is for your actual product. All the fancy AJAX this app will have is certainly a feature, but that stuff these days is getting more and more expected rather than a feature. The one feature that we will focus on with this app is "public sharing". Each list will have a unique URL that can be publicly shared. A visitor visiting this URL can see the list in it's exact current state, but not interact with it as far as editing/adding/deleting.

Where We‟re At

Up to this point, we‟ve planned the way our app is going to look, as well as given ourselves a basic idea of how the app is going to function. The next step is to figure out what‟s going to happen behind the scenes to allow our app to work the way we‟ve planned. Okay, So We Know Ho w It Looks, but How Does It Work?

In order to keep a list available after a user logs out of our app, we‟ll need to store list information in a database. And, of course, to access that database we‟re going to need some kind of server-side scripting language. For this app, we made the choice to go with a combination of MySQL and PHP to handle all our behind-the-scenes data handling and storage. Data Storage—P lanning and Database Structure

Our first step is to decide how we want to organize list data. Since this app is fairly simple, we‟ll only need three tables in our database. The first table will store user information, and the second will store list information. The third table will keep track of list items. Creating the Database Of course, before we can create our tables, we‟ll need a database to work with. For anyone working along at home, we‟ll be operating under the assumption that you‟re building and testing locally (we recommend XAMPP). Navigate to http://localhost/phpmyadmin and open the SQL tab. You can use the GUI if you want, but we‟re going to use raw SQL commands for learning purposes. The database will be named cl_db , which is all the information that is required to build the database. However, we want to make sure that our users can use characters from any language

in their lists, so it‟s also a good idea to specify the collation and character set of the database. We‟ll be using the UTF-8 character set with general collation, which supports multilingual characters and is case-insensitive. The command to create this database is: CREATE DATABASE `cl_db`

DEFAULT CHARACTER SET utf8

COLLATE utf8_general_ci;

Execute this command from the SQL tab in phpMyAdmin and the new database will become available. Now that we‟ve got a database, we‟re ready to build our tables. Table 1: User Information Using our list app doesn‟t require a high security clearance; all we need to know is that you‟ve got an email address and that it‟s real. To determine that an email address is real, we‟ll be sending new users a confirmation link in an email, which they need to follow before using our app. This means we need to have a unique confirmation link and a place to store whether or not an account has been verified. Of course, we also need to store the user‟s email address, and in the interest of keeping redundant data storage to a minimum, we‟ll assign each user a unique numeric identifier. The MySQL command to build this table will look like this: CREATE TABLE cl_db.users ( UserID

INT PRIMARY KEY AUTO_INCREMENT,

Username

VARCHAR(150) NOT NULL,

Password

VARCHAR(150),

ver_code

VARCHAR(150),

verified

TINYINT DEFAULT 0

)

Table 2: List Information List information is fairly straightforward. Each list will have a unique identifier, a unique URL, and the identifier of the user that owns the list. This helps us limit the amount of redundant information that needs to be stored. To build this table, execute the following MySQL command in phpMyAdmin‟s SQL tab: CREATE TABLE cl_db.lists ( ListID

INT PRIMARY KEY AUTO_INCREMENT,

UserID

INT NOT NULL,

ListURL

VARCHAR(150)

)

Table 3: List Items Finally, we need a table that will store our list items. Each list item needs a unique identifier, the ID of the list it belongs to, and the information the user enters as his or her list item. Also, to support features we‟ll be adding later on, we also need tokeep a record of the item‟s position and color. Execute this command in the SQL tab of phpMyAdmin: CREATE TABLE cl_db.list_items

(

ListItemID

INT PRIMARY KEY AUTO_INCREMENT,

ListID

INT NOT NULL,

ListText

VARCHAR(150),

ListItemDone

INT NOT NULL,

ListItemPosition INT NOT NULL,

ListItemColor

INT NOT NULL

)

NOTE: The ListItemDone field was omitted in the original post of this article. It was added here after being pointed out in the comments by FuSi0N.

The database with our three tables

Now we have our database and the three tables we‟ll need to build our app. Next, we‟ll plan how we‟re going to create and access our database information using PHP. Data Handling—Planning and Script Organization

Before we start coding, it‟s always a good idea to take a moment and map out everything that needs to be done. That way, we can group tasks into logical arrangements. Because great code starts with great organization, we‟ll be using an object-oriented approach. Planning our PHP Classes Object-oriented programming provides an easy way to keep related functions grouped together. After learning object-oriented programming, it becomes an incredibly powerful tool that increases portability, readability, and usability of scripts. Our app is pretty simple, so we‟ll only need two classes. The first class is going to handle user interactions, such as registering, updating information, and logging in and out. The second class will handle list interactions, such as adding, deleting, and moving list items. User Actions Class Our first class, which we‟ll name ColoredListsUsers , needs to handle all the actions our app will perform that are user account-related. Again, this is a pretty simple application, so when we map out everything that users can do with their account, we end up with pretty short list:      

Create an account Verify the account Update the account email address Update the account password Retrieve a forgotten password Delete the account

In addition to those methods, we‟ll also need some support methods, such as one that will send a verification email. We‟ll define these methods as we build the app in later installments of this series. List Actions Class The list actions class, which we‟ll call ColoredListsItems , also has a pretty short list of methods. This class will handle everything else our app does, which is anything a user can do with his or her list items. The list of available actions ends up looking like this:



Create a list item

   

Update a list item Delete a list item Change a list item‟s position Change a list item‟s color

Action Handling Scripts Finally, we‟ll need a couple action-handling scripts. These will determine what the user‟s desired action is, create an instance of the proper object, and call the correct method. As we build our app, we‟ll go into more detail on how these scripts will work. Moving On

In our next installment of this series, we‟ll create the application workflow. Make sure you‟re subscribed to CSS-Tricks so you don‟t miss out Developing a Workflow

We have a great start going on our list application at this point. The “big idea” is in place, we know how we want the lists to be displayed and interacted with, and we have some back-end structure in place to deal with users and all the data that goes along with these lists. It was a good idea to start with the “meat” of the app, but there is a little bit more that goes into a full application. Because we have users, that means we need a sign up form and a log in area for returning users. Because users can be forgetful, we need a „Lost Password‟ feature. Because users should be just as concerned about security as we are, users need to be able to change their passwords, change their login, and delete their accounts. Our one-page app has just turned into a four or five page app, so we‟re going to need to think about some workflow. There will be two different states for the homepage: logged in and logged out. While logged out, people need a way to sign in and to register, and this will be essentially the “sales” page too, explaining the app. Logged in, the homepage will be the user‟s list itself. Logged in users will also need to do some ancillary stuff related to their account, like change their email, change their password, and delete their account, as well as a way to log out. These ancillary options are probably best served on an account page. So now we are looking at at least two new pages: Account Settings and Registration. Here is some flow:

Basic app workflow It‟s not pretty folks, but that‟s what sketching is. It‟s fast and it‟s just to help you think and plan for the things you need. Bringing It to Life Photoshop

Our developer is already ahead of us, thinking about the data they need and how this app is going to actually work. So we‟d better get started actually designing here. Homepage (Logged In) This is the meat of our application so let‟s start here. The list is obviously the most important thing, so let‟s keep the header small and keep the list front and center. List items are big colored blocks with buttons for their associated actions nearby.Below the list a box for entering new list items.

The home page as it appears when logged in Homepage (Logged Out) When logged out, the homepage is going to act more like a “sales” page. Not that we plan to charge for it, but just to explain and get people interested in using it. There isn‟t much to say about a list app, so we‟ll keep it simple.

When logged out, we‟ll encourage the visitor to sign up Small Bits We‟ve been designing long enough to know we might as well make the little buttons into a separate file and keep them together as a sprite (a sprite is multiple images combined into one to save HTTP requests, in our case, also the rollover states). So we‟ll do that and throw together a favicon while we‟re at it.

All the list item tabs

Favicon

Registration Our intention with registration is going to be extremely simple. We‟re going to ask for a user‟s email and that‟s it. They will be sent an email with a link in it to complete registration. The link in that email will “activate” their account and they can choose the password at that time. So, our registration page can be pretty darn simple.

The registration form As small as this is, this registration page sets the stage for other forms. We have a label/input pair here that can be used for any input/pair in any of our site‟s forms. Account We‟ll use the same form design as the registration page here. It‟s not cheating or being lazy, it‟s good design through consistency!

Account controls Buttons Notice the change in buttons. They are now big, orange and rounded. Much more button-like don‟t you think? Again for consistency, let‟s make this the default for all buttons across the site.

Site buttons, looking button-like

Moving on

The developer now has plenty to go on to start fleshing out the user interactions for the site. And we have plenty to go on to start getting the HTML and CSS for all this ready, and ultimately to AJAX this puppy up and get it working. It's time to get our hands dirty with some markup! We know we have a couple different pages to deal with here. The main page of course, which acts as both our list page and sales page depending on login status. But then we have sign in and sign up pages and account pages. So let's be smart and work modularity. That means we'll make files like "header.php" and "close.php" that we can include on multiple pages so we don't have to repeat common code (e.g. the DOCTYPE, analytics code, and ubiquitous things like that. ALL SERIES NAVIGATION

        

Part 1 - Planning the App: Basic Idea and Design Part 2 - Planning the App: Database Architecture and Development Approach Part 3 - Designing the App: Workflow Map and Photoshop Design Part 4 - Designing the App: HTML and CSS Part 5 - Developing the App: User Interaction Part 6 - Developing the App: Adding AJAX Interactivity Part 7 - Developing the App: List Interaction Part 8 - Security & The Future

And finally.... the application!

Colored Lists

Web Root Organization This is what we have for files at the root of our web directory so far. All the major views have their own PHP files. We have subdirectories for images and "common" files. and we have a few loose files like CSS and the favicon.

Our developer will surely be adding more files. He's going to need PHP files for interacting with the database and doing all the list interactions.

Header



Colored Lists |











Colored Lists



Log out Your Account

Sign up   Log in



Right away in the header we've run across a few things where we need to be smart and leave notes for the developer, but give him the things he needs. In the page title, we've left a note to do something smart there. Different pages need differnet page titles, so clearly something dynamic needs to happen there. Then with our control buttons (e.g. Account / Logout) those buttons will be different depending on the logged in state of the user. So we'll just let the developer jump in there and make those things function correctly. So at this point we have the top of a page. We are leaving the body, html, and #page-wrap elements open, as beyond that is the main content of the page. Before we get into that main content, let's toss in the sidebar and footer areas so we have a complete skin.

Footer Our design doesn't call for much of a footer, so we'll just close up those open elements and add a note to put analytics here.









Sidebar Our design calls for a bit of a sidebar. Right now, all we'll use it for is a few notes on using the application. But it's nice to have some open room for content, as it's extremely likely that room will be needed for additional things as the app grows.



Reminders

Your list automatically saves Double-click list items to edit them



Main Page Now that we have our "modules" complete, let's dig into a real page. The template for building any page will be like this:





This site just doesn't work, period, without JavaScript















Logged in (The List) Walk the dog



Pick up dry cleaning

Milk The list itself will just be a regular ol' unordered list. We'll use CSS class names for the colors. But then we need a bunch of controls for the list items. That's what all those divs are inside the list items. There are empty divs for dragging, changing color, deleting, and checking off list items. We need these for the CSS so we can target them and style them. We're smart designers though, we know this markup is merely temporary. These lists will be dynamically generated by the application. Just looking at all those empty control divs; we know that those are probably automatically generated by the JavaScript. That's fine, we need the HTML in there now to set the stage and have everyone on the same page. Why the spans inside the list items? Just being smart. Because the list items wrap more than just the text, it's likely we'll need some kind of hook to target just the text later on. Now we need to get an input on this page for adding new list items. Our developer will be all over this, but we'll put the basics in so we can style them.









Then one of our applications features is having sharable public URL's for our lists. Let's put that in here too.

Public list URL: URL GOES HERE (Nobody but YOU will be able to edit this list) Ahhh, more work for the developer! But he's ready for it. This public URL business leads us into another possible scenario. We need this main page to be capable of displaying a list without showing the input form or all the list controls. Basically you can just look at the list but not interact with it. (Like if you wanted to send your mom your Christmas list!)

Logged out (Public list) Walk the dog

Pick up dry cleaning

Milk This will be exactly the same as the list above, only no control tabs, no form to add new items, and no public URL area (hey, they are already here, what do they need the URL for). We know this this probably will just be a change in how the backend code outputs the list. But whatever, if we create this, everybody is on the same page.

Logged out (Sales) We might do something fancy someday for this, but for now, our big idea is just a cool graphic showing that this area is potentially where your new list will be and a big ol' arrow showing people where they can sign up.



Account Page As a quick reminder, we us this structure for all pages, including this one.















That's the beauty of working modularly, all common content is included so updates down the line are much easier.

The account page is going to have several forms on it: one for updating email, one for updating password, and a button for users to delete their accounts. Again, our developer will be all over these forms filling them up with hidden inputs that pass along data and adding in action URLs and methods and all that. We'll leave that to him, but this gives us enough to style.

Your Account

Change Email Address





Change Password

New Password

Repeat New Password





Other "Form" Pages Now that we've done the account page, we have pretty much covered all the bases for the other "form" style pages. Sign up, sign in, forgot your password, they are all just simpler versions of the account page. Since we'll have styled the basic label/input format, the header format, and the "button" format, the developer can easily create these pages himself copying the basic format and CSS classes from the account page.

The CSS Reset /* RESET */ * { margin: 0; padding: 0; } body { font: 14px/1.1 Helvetica, Sans-Serif; background: url(images/stripe.png) repeat-x; } .clear { clear: both; } img, a img { border: none; } input { outline: none; } Just getting things cleaned up.

Structure /* STRUCTURE */ body { font: 14px/1.1 Helvetica, Sans-Serif; background: url(images/stripe.png) repeat-x; } #page-wrap { width: 960px; margin: 6px auto 50px; position: relative; } hr { height: 1px; background: #ccc; clear: both; margin: 20px 0; border: none; display: block; }

Not too much complicated formatting for our little one-page app.

Typography /* TYPOGRAPHY */ a { text-decoration: none; color: #900; border-bottom: 1px dotted #900; outline: none; } h1 { font: bold 36px Helvetica, Sans-Serif; margin: 0 0 8px 0; } h2 { margin: 0 0 10px 0; } p { margin: 0 0 6px 0; } .button { background: url(http://cdn.css-tricks.com/images/button-bg.png) repeat-x; -moz-border-radius: 5px; padding: 6px 12px; border: none; color: white; cursor: pointer; text-shadow: 0 1px 1px #666; -webkit-border-radius: 5px; -webkit-box-shadow: 0 1px 3px #999; -moz-box-shadow: 0 1px 3px #999; font: bold 16px Helvetica; } .button:hover { background-position: bottom left; } .red { background: red; color: white; font-size: 12px; padding: 3px; } This isn't really a content-based app, so we don't have a whole heck of a lot of text formatting. However we do have page headers, links, and buttons, so we'll set those up here.

Header /* HEADER */ #header { height: 68px; position: relative; } #header h1 { position: absolute; top: 0; left: 0; z-index: 2; text-indent: 9999px; overflow: hidden; } #header h1 a { display: block; text-indent: -9999px; width: 200px; height: 38px; border: none; background: url(http://cdn.csstricks.com/images/logo.png) no-repeat; } #control { width: 500px; float: right; padding: 10px 237px 0 0; text-align: right; } Our little stripe header doesn't take much. Just a little CSS image replacement for the logo and placement of our control buttons.

Lists /* LISTS */

#list { list-style: none; } #list li { position: relative; margin: 0 0 8px 0; padding: 0 0 0 70px; width: 607px; } #list li span { padding: 8px; -moz-border-radius: 5px; -webkit-border-radius: 5px; width: 589px; display: block; position: relative; } .colorBlue span { background: rgb(115, 184, 191); } .colorYellow span { background: rgb(255, 255, 255); } .colorRed span { background: rgb(187, 49, 47); color: white; } .colorGreen span { background: rgb(145, 191, 75); } .tab { background: url(images/minibuttons.png) no-repeat; height: 21px; top: 4px; } .draggertab { position: absolute; left: 0px; width: 31px; cursor: move; } .draggertab:hover { background-position: 0 -21px; } .colortab { position: absolute; left: 34px; width: 34px; background-position: -31px 0; cursor: pointer; } .colortab:hover { background-position: -31px -21px; } .deletetab { position: absolute; right: -35px; width: 15px; backgroundposition: -82px 0; cursor: pointer; } .deletetab:hover { background-position: -82px -21px; } .donetab { position: absolute; right: -17px; width: 16px; backgroundposition: -65px 0; cursor: pointer; } .donetab:hover { background-position: -65px -21px; } .crossout { position: absolute; top: 50%; left: 0; height: 1px; }

#share-area { margin: 20px 0 0 69px; width: 600px; } A lot more stuff needed here. Here we'll set up how the lists look: the colors, the spacing, the rounded corners, etc. We'll also position all the little helper controls and give them appropriate backgrounds. Notice only a single image is used, minibuttons.png. A single CSS Sprite for mad efficiency!

Forms /* FORM STUFF */ label { background: #999; color: white; padding: 3px; } input[type="text"], input[type="password"] { width: 324px; border: 3px solid #999; font-size: 18px; padding: 7px; display: block; }

#add-new input[type="text"] { width: 532px; float: left; margin: 0 10px 0 69px; } #add-new input[type="text"]:focus { border-color: #73B8BF; } #add-new input[type="submit"] { padding: 10px 12px; }

ul#list li span input[style] { width: 90% !important; } Forms across our whole site will be the same, so we set that up here. The one exception is the "Add New" area on our lists, which is basically the same as any other input except bigger and is floated to the left to accommodate the "Add" button. Since we plan to use click-to-edit, the list items temporarily turn into text inputs when doing that, so we'll plan for that by shortening the length of them to accommodate for a "Save" button.

Messaging /* MESSAGING */ .message { padding: 10px; margin: 0 0 10px 0; width: 607px; } .good { background: #9ff5b6; } .bad { color: #ef0040; } We haven't talked too much about error messaging, but we can assume that because this is a web app, there will be some of it (for example, you enter in a wrong password, your passwords don't match, you have successfully done something, etc). We'll set up one class for messages in general and then classes for good and bad versions.

Sidebar /* SIDEBAR */ #ribbon { position: absolute; right: 0; width: 125px; padding: 60px 30px 0 47px; height: 756px; top: -6px; background: url(http://cdn.csstricks.com/images/ribbon-bg.png) no-repeat; }

#ribbon ul { list-style: none; } #ribbon ul li { background: rgba(0,0,0,0.8); color: white; padding: 5px; margin: 0 0 5px 0; font-size: 12px; } Just some simple stuff for our list of reminders.

Moving Along

Our developer now has plenty to work with to make this app functional. Once he's gotten a good start on that, we'll tackle AJAX and making all those list interactions happen almost like a desktop app.

Where Are We?

Now that we have a workflow put together and the HTML and CSS to make it look good, we can actually start building the classes that will run this puppy. We‟ll focus this installment of the series on the user‟s account interactions. These include:    

Creating an Account Modifying Account Information Resetting a Lost Password Deleting an Account

Connecting to the Database

Before our class will be able to do much of anything, we need to connect to our database. To do this, we‟ll need to create a couple of small files. Defining Site-Wide Constants Our site won‟t require many constants, but in the interest of keeping them easy to maintain, we‟ll create a separate file to contain any information that is site-wide. This will be called constants.inc.php , and it will reside in a new folder called inc — this folder will contain our PHP classes as well. Creating a constants file is a good idea for pieces of information that will be used often and in different scopes throughout a site. That way, if your database changes, you‟re able to change every database connection simply by swapping out the information in one file. Inside constants.inc.php , we want to define our database credentials. Since we‟re starting out by developing locally, constants.inc.php will look like this:

As we develop, we‟ll add more to this file. Creating a PDO Object Next, we want to create a connection so that our application can communicate with our database. This file will reside in the common folder along with the header, footer, and sidebar files. This file will create a database connection using PDO (PHP Data Objects), as well as setting up a couple other site-wide features: error reporting and opening a session. The file will look like this when all‟s said and done:

Because we‟re in the development stage, we want to see any and every error that occurs on the site. By setting error_reporting() to E_ALL and changing the display_errors directive to 1 using ini_set() , we ensure that even notices will be displayed, which will keep our code cleaner and more secure. Next, we use session_start() to start a PHP session. This will allow our users to stay logged in when we build that functionality later. Finally, we include config.inc.php and create a PDO object using the constants defined within it. Note the use of the try-catch statement—this gives us the ability to use Exceptions, which help improve error handling. In this case, if the database connection fails, we‟re simply going to output the error message. Why PDO? The reason we‟re using PDO for this project is because of its support for prepared statements, which virtually eliminates the risk of SQL injection. There are other options that allow prepared statements, such as the MySQLi extension. However, PDO is not database-specific, so migrating the app to Oracle or PostgreSQL wouldn‟t require a full rewrite of our code. Also, having used both MySQLi and PDO in projects, it‟s just my personal preference to use PDO. Feel free to use whatever method of connecting to the database you prefer, but keep in mind that all database interactions in this exercise are assuming the use of PDO, and as such will probably require some reworking to accommodate your changes. Framing Out a User Interactions Class As we discussed in Part 2 of this series, we‟ll be taking the object-oriented approachwith this app. All of these actions will be contained within our ColoredListsUsers class. We‟ll also need to create several files that will display information to the user and interact with the class, which we‟ll cover as we get to them. Building the Class

To get started, we need to create the file we‟ll place in the inc folder.

class.users.inc.php

to contain the PHP class, which

With the file created, let‟s build the skeleton of the class:

Connecting the Class to the Database Before our class can do much of anything, it needs to have access to the database object we created in base.php . Our database connection within the object will be stored in a private property called $_db , and this property will be set by the classconstructor, which will accept the instance of PDO created in base.php as an argument. If no instance of PDO is passed, one will be created by the constructor. This ends up looking like this: class ColoredListsUsers

{

/**

* The database object

*

* @var object

*/

private $_db;

/**

* Checks for a database object and creates one if none is found

*

* @param object $db

* @return void

*/

public function __construct($db=NULL)

{

if(is_object($db))

{

$this->_db = $db;

}

else

{

$dsn = "mysql:host=".DB_HOST.";dbname=".DB_NAME;

$this->_db = new PDO($dsn, DB_USER, DB_PASS);

}

}

}

Now we are able to create an instance of our ColoredListsUsers object and use it to communicate with our database. Next, let‟s start building user interactions! Creating an Account

First and foremost, a user needs to be able to create an account. This will give them access to the rest of the site‟s functionality. As it stands, when a user visits our app, they‟re greeted with our “sales” page, which encourages them to click the “Sign Up” button in the top right of their screen:

The home screen of our app Clicking that “Sign Up” button directs the user to should probably be to build that page. Creating the Sign-Up Form In our app‟s root directory, create a file called inside:

/signup.php

signup.php

—our first order of business

and place the following code

Sign up





Email:











To start, we include our common/base.php and common/header.php files. Also, notice that we‟re declaring a variable called $pageTitle just before we include the header. Remember in Part 4 when we built the header file and left that comment in the title tag? Colored Lists |

We‟re going to replace that with a snippet of PHP that reads: Colored Lists |

That gives us the opportunity to post a different title for each page of our app. With the proper files included, we can then create our sign-up form. The form will submit to signup.php —itself—so we need to place an if-else check to see if the form has been submitted. If so, we create a new ColoredListsUsers object and call the createAccount() method (which we‟ll write in the next section). Finally, we close the look like this:

if-else

statement and include the footer. Our sign-up page should

The signup page. Notice the use of alternative syntax for the if-else statement. Normally, I don‟t like to use this format, but in the case of outputting HTML, I prefer the way it ends with endif; instead of a closing curly brace ( } ), which helps with readability in the script. Saving the User’s Email Address With our sign-up form ready, we need to write the createAccount() method that will be called when a user submits the form. This method will be public. Let‟s go back to inc/class.users.inc.php and declare this method: class ColoredListsUsers

{

// Class properties and other methods omitted to save space

/**

* Checks and inserts a new account email into the database

*

* @return string

a message indicating the action status

*/

public function createAccount()

{

$u = trim($_POST['username']);

$v = sha1(time());

$sql = "SELECT COUNT(Username) AS theCount

FROM users

WHERE Username=:email";

if($stmt = $this->_db->prepare($sql)) {

$stmt->bindParam(":email", $u, PDO::PARAM_STR);

$stmt->execute();

$row = $stmt->fetch();

if($row['theCount']!=0) {

return " Error "

. " Sorry, that email is already in use. "

. "Please try again. ";

}

if(!$this->sendVerificationEmail($u, $v)) {

return " Error "

. " There was an error sending your"

. " verification email. Please "

. "contact "

. "us for support. We apologize for the "

. "inconvenience. ";

}

$stmt->closeCursor();

}

$sql = "INSERT INTO users(Username, ver_code)

VALUES(:email, :ver)";

if($stmt = $this->_db->prepare($sql)) {

$stmt->bindParam(":email", $u, PDO::PARAM_STR);

$stmt->bindParam(":ver", $v, PDO::PARAM_STR);

$stmt->execute();

$stmt->closeCursor();

$userID = $this->_db->lastInsertId();

$url = dechex($userID);

/*

* If the UserID was successfully

* retrieved, create a default list.

*/

$sql = "INSERT INTO lists (UserID, ListURL)

VALUES ($userID, $url)";

if(!$this->_db->query($sql)) {

return " Error "

. " Your account was created, but "

. "creating your first list failed. ";

} else {

return " Success! "

. " Your account was successfully "

. "created with the username $u."

. " Check your email!";

}

} else {

return " Error Couldn't insert the "

. "user information into the database. ";

}

}

}

This method follows several steps to create an account: first, it retrieves the posted email address from the form (stored in the $_POST superglobal) and generates a hard-toguess verification code (the SHA1 hash of the current timestamp); second, it makes sure the supplied email address isn‟t already in use; third, it generates and sends a verification email to the user with instructions on how to verify their account (we‟ll define the method that does this in the next section); fourth, it stores the email address and verification code in the database; and finally, it creates a list for the user.

Each of these steps is monitored, and if any of them should fail, a specific error message is generated. Upon success, a message is generated to let the user know they should expect an email. Generating and Sending a Verification Email When the user creates an account, we need to send them an email with a link that will confirm their account. This is a precautionary measure that proves the user provided a real email address that they have access to and prevents a ton of spam accounts from being created easily. To send the email, we‟ll be using the built-in mail() function. In inc/class.users.inc.php , create the private sendVerificationEmail() method by inserting the following code: class ColoredListsUsers

{

// Class properties and other methods omitted to save space

/**

* Sends an email to a user with a link to verify their new account

*

* @param string $email

* @param string $ver

* @return boolean

The user's email address

The random verification code for the user

TRUE on successful send and FALSE on failure

*/

private function sendVerificationEmail($email, $ver)

{

$e = sha1($email); // For verification purposes

$to = trim($email);

$subject = "[Colored Lists] Please Verify Your Account";

$headers =