Editing Courses/Design & Technique-Essential Web Design/Q2/05 (section)

=Interacting with the user=

==With text==
One of the most common ways to receive textual input from web users is by using parent HTML tag <code><form></code> and the children tags <code><input></code>


HTML Forms overview https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Forms

==input tag==
<code><input></code> is the element that receives the interaction from the user. 

It can take a variety of forms and behaviors, depending on the '''type attribute'''

In the example only type="text" and type="submit" are used, but there are many more type attribute value to be used. See them in 
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input#Attributes

'''required''' attribute, means that the user must fill in a value before submitting a form

'''placeholder''' attribute - provides A hint to the user of what can be entered in the control


== jQuery ==
Our Javascript code is listening to the event submit by <code>$("form#userQuestions").submit(</code>

When submit happens, it asks for the values of <code>$('#userName').val();</code> and <code>$('#userLocation').val();</code>
which get stored in the variables <code>userName</code> and <code>userLocation</code>

and is finally added of text to the <nowiki><h2></nowiki> just appended.

Note: <code>event.preventDefault();</code> is there to prevent the form submission to produce its default behavior, which would be to refresh the page. This way we can get the values of $('form#userName') and $('form#userLocation') and keep the form as it was

==Adventure: with text user input==
Expanding last week's adventure game, but with added user input interaction.

=== Code explained ===
The HTML page is divided in 2 divs: 
*  $('div#form') - a div w/ a form that receives user input   
*  $('div#scene') - a div that contains text, image and buttons for each scene

On start:
*  $('div#form') is SHOWN. 
*  $('div#scene') is HIDDEN (css display:none)

On $("form#userQuestions").submit():
*  userName, userLocation are STORED and '''REPLACED''' in scenes object %%userName%% and %%location%% 
* $('div#scene') is FILLED with values from scene_1, with the FUNCTION: replace_scene('scene_1');
*  $('div#form') is HIDDEN. 
*  $('div#scene') is SHOWN (css display:block)

User is on scene 1:
* every time the user CLICKS a button: $("button").click()
** a next_scene is CREATED from the clicked button 'name' attribute
** replace_scene()  for the next_scene

===code===
<source lang="html4strict">
<!DOCTYPE html>
<html>
<head>
  <script src="http://code.jquery.com/jquery-1.11.3.min.js"></script>

  <title>Choose your own adventure</title>
  <meta charset="utf-8" />
    <style>
    img{width: 300px;}
button{ margin-left:10px;}
input {margin-bottom:10px;}
div#scene {display: none;}

    </style>
</head>
<body>

<div id="form">
    <h1 id="question">In order to begin, you must tell...</h1>
<form id="userQuestions">
    <input name="userName" id="userName" required="" placeholder="Your first name" type="text">
    <br/>
    <input name="userLocation" id="userLocation" required="" placeholder="Your current location" type="text">
    <br/>
  <input value="Send" type="submit">
</div>

<div id="scene">
  <p class="msg"></p>
  <img class="image" />
   <br/>
  <div class="buttons">
      <p class="question"></p>
    <!-- buttons: will have to be created dynamically -->
  </div>
</div>

<script>
    //object containing collection of scenes:
    var scenes={ 
        scene_1: {title:"start", msg:"<b>Hey %%userName%%</b>, welcome to the game. The game will have as starting point <b>%%location%%</b>.", img: "http://thepiratebook.net/wp-content/uploads/2015/11/Sonideros_L.Radwanski_PirateBook_2.jpg", question:"What do you want to do next?", 
connect:[2,5] },  
        scene_2: {title:"walk", msg:"From %%location%%, walk in a straight line until you encounter and obstacle", img: "", question:"How large is the object?", connect:[3,4] },  
        scene_3: {title:"small", msg:"Take the object with you. Walk back to to you started. Leave the object there and look around. Is %%location%% still the same place?", img: "", question:"Go to", connect:[1] },  
        scene_4: {title:"large", msg:"%%userName%%, leave a message in the obstacle for someone to see", img: "", question:"Go to", connect:[1] },  
        scene_5: {title:"follow" , msg:"Follow a moving object, until you feel bored.", img:"", question:"How is this object?",  connect:[3,6,4] },  
        scene_6: {title:"too far" , msg:"Look at the object from where you are now. Move your head slowly towards the sky above %%location%%. Look at it carefully.", img: "", question:"Go to",  connect:[1] },  
    }


$("form#userQuestions").submit(function(event){ //when form is submitted
        // form user-input values
        var userName = $('#userName').val();
        var userLocation = $('#userLocation').val();

        //for loop: replaces sentences placeholders (%%placeholder%%) w/ user-input values
        for (var key in scenes) {
            var newscene = scenes[key];
            console.log(userName, userLocation);
            newscene = newscene.msg.replace('%%userName%%', userName)
                               .replace('%%location%%', userLocation);      
            scenes[key].msg=newscene; 
        }

        event.preventDefault();
        $("#userName").val(''); //clean inputs
        $("#userLocation").val(''); //clean input#userName
        $('div#form').css('display', 'none'); //hide form

        replace_scene('scene_1'); // start scene 1 
        $('div#scene').css('display', 'block'); //make visible div#scene
})



function replace_scene(n){ // function to replace the scene content base on its number
    var scene = scenes[n];

    $("p.msg").html( scene.msg );
    $("img.image").attr( "src", scene.img );
    $("p.question").html( scene.question );
    
    for (var i=0; i < scene.connect.length; i=i+1) { var numb='scene_'+scene.connect[i]; //create buttons
                                                     var next_title=scenes[numb].title; 
                                                     button = document.createElement('button')
                                                     $(button).text(next_title);
                                                     $(button).attr('name', numb);
                                                     $('div.buttons').append(button);

                                                     $("button").click( // when user makes choice (click any button)
                                                         function(){ 
                                                             $("button").remove();//remove all buttons
                                                             var next_scene = $(this).attr('name'); //get next scene through the button name attribute
                                                             replace_scene(next_scene); //move to another scene
                                                         })
                                                   }

}
</script>
</body>
</html>
</source>