is1500: introduction to web development collecting data with forms martin schedlbauer, ph.d....

IS1500: Introduction to Web DevelopmentCollecting Data with Forms

Martin Schedlbauer, [email protected]

Collecting Data with Forms 2

FORM CONCEPTSCollecting Data with Forms

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What is an Form?

• Forms are used to collect information from a user, e.g., reservations, orders, etc.

• The collected data is then passed to the web server for processing or storage in a database.

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How do Forms Work?

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1. HTML form on the browser is filled out by the user

2. Upon submit the data is sent to a forms processing program on the web server

Form Processor1

1The form processor on the web server is written in a computer programming language such as PHP, ASP.NET, Zoho Deluge, Ruby, Java, C++, Python, etc.

Database

3. Data is stored in a database or sent as an email

Name=Mark, LimoneAddress=1 Main St.


Form Builders

• Form builders simplify the creation of forms and don’t require HTML coding.

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SECURING FORMS WITH CAPTCHACollecting Data with Forms

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What is CAPTCHA?• A CAPTCHA is a program that protects

websites against bots by generating and grading tests that humans can pass but current computer programs cannot.

• For example, humans can read distorted text as the ones shown to the side, but current computer programs can't.

• So, the idea is that if a bot can't decipher the CAPTCHA code and the code is correct that the form must have been filled out by a human.

• This can help avoid getting spam through forms or bad data into a database.

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History of CAPTCHA

• The term CAPTCHA was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas Hopper and John Langford of Carnegie Mellon University.

• CAPTCHA = Completely Automated Public Turing Test To Tell Computers and Humans Apart

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Form with Captcha Fields

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• The form can only be submitted to the forms processor if the CAPTCHA verification code is correctly filled in.

• This prevents robots (automated form fillers) from filling out the form and flooding the forms database or email processor with spam.


JOTFORM FORMSCollecting Data with Forms

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JotForm Form Elements

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Form Element Properties

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Embedding the Form

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E-Mail Forms Processor

• JotForm has a built-in forms processor that emails the form to a select email address.

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HTML FORM ELEMENTSCollecting Data with Forms

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Form Element

• The <form> tag is used to create an HTML form

• All form input elements are contained within the <form> tag

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<form>…input elements…</form>


HTML5 Forms

• Forms can contain input elements like text fields, checkboxes, radio-buttons, submit buttons and more

• A form can also contain select lists, textarea, fieldset, legend, and label elements

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Form Attributes• name attribute is used to give a name to the

form• action attribute specifies the action to be

taken when the form is submitted • method attribute is used to specify the type of

request sent to the server (GET/POST)

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<form name="DemoForm" action="demo_form.php" method="get">...</form>


Input Elements: Text

• <input type="text"> defines a one-line input field that a user can enter text into:

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<form>First name: <input type="text" name="firstname" /><br>Last name: <input type="text" name="lastname" /></form>


Input Elements: Password

• <input type="password"> defines a password field:

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<form>Password: <input type="password" name="pwd" /></form>


Input Elements: Radio Buttons

• <input type="radio"> defines a radio button. Radio buttons let a user select ONLY ONE of a limited number of choices:

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<form><input type="radio" name="gender" value="male" />Male<br><input type="radio" name="gender" value="female" />Female</form>


Input Elements: Checkboxes

• <input type="checkbox"> defines a checkbox. Checkboxes let a user select ZERO or MORE options of a limited number of choices.

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<form><input type="checkbox" name="vehicle" value="Bike" />I have a bike<br><input type="checkbox" name="vehicle" value="Car" />I have a car </form>


Input Elements: Submit Button

• <input type="submit"> defines a submit button.

• A submit button is used to send form data to a server

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<form name="input" action="demo_form_action.asp" method="get">Username: <input type="text" name="user" /><input type="submit" value="Submit“ /></form>


Drop-Down List

• <select> defines a drop-down list with multiple values:

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<form action=""><select name="cars"><option value="volvo">Volvo</option><option value="saab">Saab</option><option value="fiat" selected>Fiat</option><option value="audi">Audi</option></select></form>


TextArea

• <textarea> defines a text box with multiple lines:

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<textarea rows="10" cols="30">The cat was playing in the garden.</textarea>


Hidden Fields

• Hidden fields are form fields that contain data supplied by the programmer that are not visible to the user but only to the forms processor.

• This hidden field will send the value “aValue” to the forms processor under the name “var”.

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<input type="hidden" name="var" value="aValue" />


HTML5 Form Elements: Datalist

• The <datalist> element specifies a list of pre-defined options for an <input> element

• The <datalist> element is used to provide an "autocomplete" feature on <input> elements. Users will see a drop-down list of pre-defined options as they input data.

• Use the <input> element's list attribute to bind it together with a <datalist> element.

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HTML5 Form Elements: Datalist

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<form action="demo_form.asp" method="get"><input list="browsers" /><datalist id="browsers"> <option value="Internet Explorer"> <option value="Firefox"> <option value="Chrome"> <option value="Opera"> <option value="Safari"></datalist> </form>


HTML5 Input Types: Number

• <input type="number"> is used for input fields that should contain a numeric value.

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<input type="number" value="3" name="quantity" min="1" max="5" />

Note: Not supported in <= IE9


HTML5 Input Types: Date

• <input type="date"> is used for input fields that should contain a date.

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<input type="date" name="bday" min="2000-01-02" />

Note: Only supported in Safari and Chrome


HTML5 Input Types: Color• <input type="color"> is used for input fields

that should contain a color.

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<form action="demo_form.asp"> Select your favorite color: <input type="color" name="favcolor" value="#ff0000" /> <input type="submit" value="Send" /></form>

Note: Not supported in Safari and IE9


Input Elements: Range• <input type="range"> defines a slider• The range and step constraints are enforced

even during user input and the value attribute, if specified, must have a valid floating point number.

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<form action="demo_form.asp" method="get" >0<input type="range" id="a" name="a" min="-100" max="100" step="10" value="50" />100</form>



HTML5 Input Types: Month

• <input type="month"> allows the user to select a month and year.

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<form action="demo_form.asp"> Birthday (month and year): <input type="month" name="bdaymonth" /> <input type="submit" value="Send" /></form>

Note: Not supported in IE and FireFox


HTML5 Input Types: Time

• <input type="time"> allows the user to select a time (no time zone).

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<form action="demo_form.asp"> Select a time: <input type="time" name="usr_time" /> <input type="submit" value="Send" /></form>

Note: Only supported in Safari and Chrome


HTML5 Input Types: Email

• <input type="email"> is used for input fields that should contain an e-mail address

• validated automatically when submitted

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<form action="demo_form.asp"> E-mail: <input type="email" name="email" /> <input type="submit" value="Send" /></form>

Note: Not supported in Safari and <= IE9


HTML5 Input Types: Image • The input type="image" sends the X and Y

coordinates of the click that activated the image button

• When the button is clicked, the input is sent to the server as “name=&x=20&y=10”

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<form action="demo_form.asp"> Name: <input type="text" name="name“ /><br> <input type="image" src="img_submit.gif" alt="Submit" width="25" height="25" /></form>


HTML5 Input Types: URL

• <input type="url"> is used for search fields (a search field behaves like a regular text field)

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<form action="demo_form.asp"> Add your homepage: <input type="url" name="homepage" /> <input type="submit" value="Send" /></form>



HTML5 Attributes: autocomplete• When autocomplete is on, the browser

automatically completes values based on values that the user has entered before.

• It is possible to have autocomplete "on" for the form, and "off" for specific input fields, or vice versa.

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<form action="demo_form.asp" autocomplete="on"> First name:<input type="text" name="fname" /><br> Last name: <input type="text" name="lname" /><br> E-mail: <input type="email" name="email" autocomplete="off" /><br> <input type="submit" /></form>

Note: Not supported in Opera


HTML5 Attributes: novalidate

• The novalidate attribute is a boolean attribute.

• When present, it specifies that the form-data (input) should not be validated when submitted.

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<form action="demo_form.asp" novalidate> E-mail: <input type="email" name="user_email" /> <input type="submit" /></form>

Note: Not supported in Safari


HTML5 Attributes: autofocus

• The autofocus attribute is a boolean attribute.• When present, it specifies that an <input>

element should automatically get focus when the page loads.

• Let the "First name" input field automatically get focus when the page loads:

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First name:<input type="text" name="fname" autofocus />


HTML5 Attributes: required

• The required attribute is a boolean attribute.• When present, it specifies that an input field

must be filled out before submitting the form.

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<form action="demo_form.asp"> Username: <input type="text" name="usrname" required /> <input type="submit" /></form>



HTML5 Attributes: placeholder • The placeholder attribute specifies a hint that

describes the expected value of an input field• The hint is displayed in the input field before

the user enters a value.

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<form action="demo_form.asp"> <input type="text" name="fname" placeholder="First name" /><br> <input type="text" name="lname" placeholder="Last name" /><br> <input type="submit" value="Submit" /></form>



HTML5 Attributes: multiple • The multiple attribute is a boolean attribute• When present, it specifies that the user is

allowed to enter more than one value in the <input> element

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<form action="demo_form.asp"> Select images: <input type="file" name="img" multiple /> <input type="submit" /></form>



PHP Form Handling• A simple HTML form with two input fields and a

submit button:

• On submitting the form, the form data is sent for processing to a PHP file named "welcome.php"

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<html> <body> <form action="welcome.php" method="post"> Name: <input type="text" name="name" /> <br> E-mail: <input type="text" name="email" /> <br> <input type="submit" /> </form> </body></html>


PHP Form Handling• To display the submitted data you could simply echo

all the variables as follows:

• The output would be like this:

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<html> <body> Welcome <?php echo $_POST["name"]; ?><br> Your email address is: <?php echo $_POST["email"]; ?> </body></html>


GET• Both GET and POST create an array that holds

key/value pairs of data sent to the server

• Information sent from a form with the GET method is visible to everyone

• For example: http://boatventures.com/welcome.php?name=john&[email protected]

• GET puts a limit on the amount of information that can be sent

• GET may be used for sending non-sensitive data but has the advantage that the form can be bookmarked

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POST• Information sent from a form with the POST

method is invisible to everyone• POST has no limits on the amount of

information• POST supports advanced functionality such as

support for multi-part binary input while uploading files to server

• POST may be used for sending sensitive data

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A Complete Example: Form

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<form action="http://boatventures.us/testPHP_script.php" method="post"><table> <tr> <td>Name:</td>

<td> <input type="text" name="name" /></td><td>(User's name)</td>

</tr> <tr>

<td>E-mail: </td><td><input type="text" name="email" /></td><td>(Emaild of the user to whom the email is to be sent)</td>

</tr> … <tr>

<td></td><td><input type="submit" /></td>

</tr></table></form>


A Complete Example: PHP

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<?php $name = $_POST['name']; $email = $_POST['email']; $subject = $_POST['subject']; $message = $_POST['message'];

echo "Welcome $name <br />";

// send mail mail($email,$subject,$message,"[email protected]");

echo "Email sent to $email.";?>

File named “testPHP_script.php” on AwardSpace.net in boatventure.us folder


Summary, Review, & Questions…

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is1500: introduction to web development collecting data with forms martin schedlbauer, ph.d....

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