Image modals on multi-tab page

Question

I want to create a multi-tabs page with an image modal on each tab.

I used code from w3school.com. The modal only shows on the first page but not in the others. No matter what image I click, the modal with that image will show only in the first page. I am new to web design, so I prefer to use CSS and simple JavaScript.

Can anybody help me figure out how to make the modal show on the correct page?

Edited on Oct 02, 2021, I revised my CSS and Javascript and fixed the issue using a loop. Just sharing for anyone might be interested in.

Revised JavaScript

    ///// Image display modals
    // All page modals
    var modals = document.querySelectorAll('.modal');

    // Get the image and insert it inside the modal - use its "alt" 
    // text as a caption
    var img = document.querySelectorAll("img.myImg")
    var modalImg = document.querySelectorAll("img.modal-content")
    var captionText = document.querySelectorAll(".modal-caption");

    // Get the <span> element that closes the modal
    var spans = document.getElementsByClassName("close");
 
    // When the user clicks the image, open the modal
    for (var i = 0; i < img.length; i++) {
        img[i].onclick = function() {
            for (var index in modals) {
            modals[index].style.display = "block";
            for (var index in modalImg) {
                modalImg[index].src = this.src;}; 
            for (var index in captionText) {
                captionText[index].innerHTML = this.alt;}
            }
        }
    }


    // When the user clicks on <span> (x), close the modal
    for (var i = 0; i < spans.length; i++) {
    spans[i].onclick = function() {
        for (var index in modals) {
        if (typeof modals[index].style !== 'undefined') modals[index].style.display = "none";    
        }
    }
    }

    // When the user clicks anywhere outside of the modal, close it
    window.onclick = function(event) {
        if (event.target.classList.contains('modal')) {
        for (var index in modals) {
        if (typeof modals[index].style !== 'undefined') modals[index].style.display = "none";    
        }
        }
    }

Revised CSS

* {box-sizing: border-box}

/* Set height of body and the document to 100% */
body, html {
  height: 100%;
  margin: 0;
  font-family: Arial;
}

/* Style tab links */
.tablink {
  background-color: #555;
  color: white;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  font-size: 17px;
  width: 25%;
}

.tablink:hover {
  background-color: #777;
}

/* Style the tab content (and add height:100% for full page content) */
.tabcontent {
  color: white;
  display: none;
  padding: 100px 20px;
  height: 100%;
}

#Home {background-color: red;}
#News {background-color: green;}
#Contact {background-color: blue;}
#About {background-color: orange;}

.myImg {
  border-radius: 5px;
  cursor: pointer;
  transition: 0.3s;
}

.myImg:hover {opacity: 0.7;}

/* The Modal (background) */
.modal {
  display: none; /* Hidden by default */
  position: fixed; /* Stay in place */
  z-index: 1; /* Sit on top */
  padding-top: 100px; /* Location of the box */
  left: 0;
  top: 0;
  width: 100%; /* Full width */
  height: 100%; /* Full height */
  overflow: auto; /* Enable scroll if needed */
  background-color: rgb(0,0,0); /* Fallback color */
  background-color: rgba(0,0,0,0.9); /* Black w/ opacity */
}

/* Modal Content (image) */
.modal-content {
  margin: auto;
  display: block;
  width: 80%;
  max-width: 700px;
}

/* Caption of Modal Image */
.modal-caption {
  margin: auto;
  display: block;
  width: 80%;
  max-width: 700px;
  text-align: center;
  color: #ccc;
  padding: 10px 0;
  height: 150px;
}

/* Add Animation */
.modal-content, .modal-caption {  
  -webkit-animation-name: zoom;
  -webkit-animation-duration: 0.6s;
  animation-name: zoom;
  animation-duration: 0.6s;
}

@-webkit-keyframes zoom {
  from {-webkit-transform:scale(0)} 
  to {-webkit-transform:scale(1)}
}

@keyframes zoom {
  from {transform:scale(0)} 
  to {transform:scale(1)}
}

/* The Close Button */
.close {
  position: absolute;
  top: 15px;
  right: 35px;
  color: #f1f1f1;
  font-size: 40px;
  font-weight: bold;
  transition: 0.3s;
}

.close:hover,
.close:focus {
  color: #bbb;
  text-decoration: none;
  cursor: pointer;
}

/* 100% Image Width on Smaller Screens */
@media only screen and (max-width: 700px){
  .modal-content {
    width: 100%;
  }
}

HTML

<button class="tablink" onclick="openPage('Home', this, 'red')">Home</button>
<button class="tablink" onclick="openPage('News', this, 'green')" id="defaultOpen">News</button>
<button class="tablink" onclick="openPage('Contact', this, 'blue')">Contact</button>
<button class="tablink" onclick="openPage('About', this, 'orange')">About</button>

<div id="Home" class="tabcontent">
<h2>Image Modal</h2>
<p>In this example, we use CSS to create a modal (dialog box) that is hidden by default.</p>
<p>We use JavaScript to trigger the modal and to display the current image inside the modal when it is clicked on. Also note that we use the value from the image's "alt" attribute as an image caption text inside the modal.</p>

<img id="myImg" src="img_nature.jpg" alt="Snow" style="width:100%;max-width:300px">

<!-- The Modal -->
<div id="myModal" class="modal">
  <span class="close">&times;</span>
  <img class="modal-content" id="img01">
  <div id="caption"></div>
</div>
</div>

<div id="News" class="tabcontent">
<h2>Image Modal</h2>
<p>In this example, we use CSS to create a modal (dialog box) that is hidden by default.</p>
<p>We use JavaScript to trigger the modal and to display the current image inside the modal when it is clicked on. Also note that we use the value from the image's "alt" attribute as an image caption text inside the modal.</p>

<img id="myImg" src="img_snow.jpg" alt="Snow" style="width:100%;max-width:300px">

<!-- The Modal -->
<div id="myModal" class="modal">
  <span class="close">&times;</span>
  <img class="modal-content" id="img01">
  <div id="caption"></div>
</div>
</div>

<div id="Contact" class="tabcontent">
<h2>Image Modal</h2>
<p>In this example, we use CSS to create a modal (dialog box) that is hidden by default.</p>
<p>We use JavaScript to trigger the modal and to display the current image inside the modal when it is clicked on. Also note that we use the value from the image's "alt" attribute as an image caption text inside the modal.</p>

<img id="myImg" src="img_snow.jpg" alt="Snow" style="width:100%;max-width:300px">

<!-- The Modal -->
<div id="myModal" class="modal">
  <span class="close">&times;</span>
  <img class="modal-content" id="img01">
  <div id="caption"></div>
</div>
</div>

<div id="About" class="tabcontent">
  <h3>About</h3>
  <p>Who we are and what we do.</p>
</div>

Original CSS

* {box-sizing: border-box}

/* Set height of body and the document to 100% */
body, html {
  height: 100%;
  margin: 0;
  font-family: Arial;
}

/* Style tab links */
.tablink {
  background-color: #555;
  color: white;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  font-size: 17px;
  width: 25%;
}

.tablink:hover {
  background-color: #777;
}

/* Style the tab content (and add height:100% for full page content) */
.tabcontent {
  color: white;
  display: none;
  padding: 100px 20px;
  height: 100%;
}

#Home {background-color: red;}
#News {background-color: green;}
#Contact {background-color: blue;}
#About {background-color: orange;}

#myImg {
  border-radius: 5px;
  cursor: pointer;
  transition: 0.3s;
}

#myImg:hover {opacity: 0.7;}

/* The Modal (background) */
.modal {
  display: none; /* Hidden by default */
  position: fixed; /* Stay in place */
  z-index: 1; /* Sit on top */
  padding-top: 100px; /* Location of the box */
  left: 0;
  top: 0;
  width: 100%; /* Full width */
  height: 100%; /* Full height */
  overflow: auto; /* Enable scroll if needed */
  background-color: rgb(0,0,0); /* Fallback color */
  background-color: rgba(0,0,0,0.9); /* Black w/ opacity */
}

/* Modal Content (image) */
.modal-content {
  margin: auto;
  display: block;
  width: 80%;
  max-width: 700px;
}

/* Caption of Modal Image */
#caption {
  margin: auto;
  display: block;
  width: 80%;
  max-width: 700px;
  text-align: center;
  color: #ccc;
  padding: 10px 0;
  height: 150px;
}

/* Add Animation */
.modal-content, #caption {  
  -webkit-animation-name: zoom;
  -webkit-animation-duration: 0.6s;
  animation-name: zoom;
  animation-duration: 0.6s;
}

@-webkit-keyframes zoom {
  from {-webkit-transform:scale(0)} 
  to {-webkit-transform:scale(1)}
}

@keyframes zoom {
  from {transform:scale(0)} 
  to {transform:scale(1)}
}

/* The Close Button */
.close {
  position: absolute;
  top: 15px;
  right: 35px;
  color: #f1f1f1;
  font-size: 40px;
  font-weight: bold;
  transition: 0.3s;
}

.close:hover,
.close:focus {
  color: #bbb;
  text-decoration: none;
  cursor: pointer;
}

/* 100% Image Width on Smaller Screens */
@media only screen and (max-width: 700px){
  .modal-content {
    width: 100%;
  }
}

Original JavaScript

<script>
function openPage(pageName,elmnt,color) {
  var i, tabcontent, tablinks;
  tabcontent = document.getElementsByClassName("tabcontent");
  for (i = 0; i < tabcontent.length; i++) {
    tabcontent[i].style.display = "none";
  }
  tablinks = document.getElementsByClassName("tablink");
  for (i = 0; i < tablinks.length; i++) {
    tablinks[i].style.backgroundColor = "";
  }
  document.getElementById(pageName).style.display = "block";
  elmnt.style.backgroundColor = color;
}

// Get the element with id="defaultOpen" and click on it
document.getElementById("defaultOpen").click();


// Get the modal
var modal = document.getElementById("myModal");

// Get the image and insert it inside the modal - use its "alt" text as a caption
var img = document.getElementById("myImg");
var modalImg = document.getElementById("img01");
var captionText = document.getElementById("caption");
img.onclick = function(){
  modal.style.display = "block";
  modalImg.src = this.src;
  captionText.innerHTML = this.alt;
}

// Get the <span> element that closes the modal
var span = document.getElementsByClassName("close")[0];

// When the user clicks on <span> (x), close the modal
span.onclick = function() { 
  modal.style.display = "none";
}
</script>

Answer 1

Separate function for each modal will work out now , further you can look into this and loops for small code in the near future

function openPage(pageName, elmnt, color) {
  var i, tabcontent, tablinks;
  tabcontent = document.getElementsByClassName("tabcontent");
  for (i = 0; i < tabcontent.length; i++) {
    tabcontent[i].style.display = "none";
  }
  tablinks = document.getElementsByClassName("tablink");
  for (i = 0; i < tablinks.length; i++) {
    tablinks[i].style.backgroundColor = "";
  }
  document.getElementById(pageName).style.display = "block";
  elmnt.style.backgroundColor = color;
}

// Get the element with id="defaultOpen" and click on it
document.getElementById("defaultOpen").click();


// Get the modal
var modal = document.getElementById("myModal");
// Get the image and insert it inside the modal - use its "alt" text as a caption
var img = document.getElementById("myImg");
var modalImg = document.getElementById("img01");
var captionText = document.getElementById("caption");
img.onclick = function() {
  modal.style.display = "block";
  modalImg.src = this.src;
  captionText.innerHTML = this.alt;
}
// Get the <span> element that closes the modal
var span = document.getElementsByClassName("close")[0];
// When the user clicks on <span> (x), close the modal
span.onclick = function() {
  modal.style.display = "none";
}

// Get the 2nd modal
var modal2 = document.getElementById("myModal2");
// Get the image and insert it inside the modal - use its "alt" text as a caption
var img2 = document.getElementById("myImg2");
var modalImg2 = document.getElementById("img02");
var captionText2 = document.getElementById("caption2");
img2.onclick = function() {
  modal2.style.display = "block";
  modalImg2.src = this.src;
  captionText2.innerHTML = this.alt;
}
// Get the 2nd <span> element that closes the modal
var span2 = document.getElementsByClassName("close")[1];


// When the user clicks on <span> (x), close the modal
span2.onclick = function() {
  modal2.style.display = "none";
}

// Get the 3rd modal
var modal3 = document.getElementById("myModal3");
// Get the image and insert it inside the modal - use its "alt" text as a caption
var img3 = document.getElementById("myImg3");
var modalImg3 = document.getElementById("img03");
var captionText3 = document.getElementById("caption3");
img3.onclick = function() {
  modal3.style.display = "block";
  modalImg3.src = this.src;
  captionText3.innerHTML = this.alt;
}
// Get the 2nd <span> element that closes the modal
var span3 = document.getElementsByClassName("close")[2];


// When the user clicks on <span> (x), close the modal
span3.onclick = function() {
  modal3.style.display = "none";
}

* {
  box-sizing: border-box
}


/* Set height of body and the document to 100% */

body,
html {
  height: 100%;
  margin: 0;
  font-family: Arial;
}


/* Style tab links */

.tablink {
  background-color: #555;
  color: white;
  float: left;
  border: none;
  outline: none;
  cursor: pointer;
  padding: 14px 16px;
  font-size: 17px;
  width: 25%;
}

.tablink:hover {
  background-color: #777;
}


/* Style the tab content (and add height:100% for full page content) */

.tabcontent {
  color: white;
  display: none;
  padding: 100px 20px;
  height: 100%;
}

#Home {
  background-color: red;
}

#News {
  background-color: green;
}

#Contact {
  background-color: blue;
}

#About {
  background-color: orange;
}

.myImg {
  border-radius: 5px;
  cursor: pointer;
  transition: 0.3s;
}

.myImg:hover {
  opacity: 0.7;
}


/* The Modal (background) */

.modal {
  display: none;
  /* Hidden by default */
  position: fixed;
  /* Stay in place */
  z-index: 1;
  /* Sit on top */
  padding-top: 100px;
  /* Location of the box */
  left: 0;
  top: 0;
  width: 100%;
  /* Full width */
  height: 100%;
  /* Full height */
  overflow: auto;
  /* Enable scroll if needed */
  background-color: rgb(0, 0, 0);
  /* Fallback color */
  background-color: rgba(0, 0, 0, 0.9);
  /* Black w/ opacity */
}


/* Modal Content (image) */

.modal-content {
  margin: auto;
  display: block;
  width: 80%;
  max-width: 700px;
}


/* Caption of Modal Image */

.caption {
  margin: auto;
  display: block;
  width: 80%;
  max-width: 700px;
  text-align: center;
  color: #ccc;
  padding: 10px 0;
  height: 150px;
}


/* Add Animation */

.modal-content,
.caption {
  -webkit-animation-name: zoom;
  -webkit-animation-duration: 0.6s;
  animation-name: zoom;
  animation-duration: 0.6s;
}

@-webkit-keyframes zoom {
  from {
    -webkit-transform: scale(0)
  }
  to {
    -webkit-transform: scale(1)
  }
}

@keyframes zoom {
  from {
    transform: scale(0)
  }
  to {
    transform: scale(1)
  }
}


/* The Close Button */

.close {
  position: absolute;
  top: 15px;
  right: 35px;
  color: #f1f1f1;
  font-size: 40px;
  font-weight: bold;
  transition: 0.3s;
}

.close:hover,
.close:focus {
  color: #bbb;
  text-decoration: none;
  cursor: pointer;
}


/* 100% Image Width on Smaller Screens */

@media only screen and (max-width: 700px) {
  .modal-content {
    width: 100%;
  }
}

<button class="tablink" onclick="openPage('Home', this, 'red')">Home</button>
<button class="tablink" onclick="openPage('News', this, 'green')" id="defaultOpen">News</button>
<button class="tablink" onclick="openPage('Contact', this, 'blue')">Contact</button>
<button class="tablink" onclick="openPage('About', this, 'orange')">About</button>

<div id="Home" class="tabcontent">
  <h2>Image Modal</h2>
  <p>In this example, we use CSS to create a modal (dialog box) that is hidden by default.</p>
  <p>We use JavaScript to trigger the modal and to display the current image inside the modal when it is clicked on. Also note that we use the value from the image's "alt" attribute as an image caption text inside the modal.</p>

  <img id="myImg" src="img_nature.jpg" alt="Snow" style="width:100%;max-width:300px">

  <!-- The Modal -->
  <div id="myModal" class="modal">
    <span class="close">&times;</span>
    <img class="modal-content" id="img01">
    <div id="caption" class="caption"></div>
  </div>
</div>

<div id="News" class="tabcontent">
  <h2>Image Modal</h2>
  <p>In this example, we use CSS to create a modal (dialog box) that is hidden by default.</p>
  <p>We use JavaScript to trigger the modal and to display the current image inside the modal when it is clicked on. Also note that we use the value from the image's "alt" attribute as an image caption text inside the modal.</p>

  <img id="myImg2" class="myImg" src="img_snow.jpg" alt="Snow" style="width:100%;max-width:300px">

  <!-- The Modal -->
  <div id="myModal2" class="modal">
    <span class="close">&times;</span>
    <img class="modal-content" id="img02">
    <div id="caption2" class="caption"></div>
  </div>
</div>

<div id="Contact" class="tabcontent">
  <h2>Image Modal</h2>
  <p>In this example, we use CSS to create a modal (dialog box) that is hidden by default.</p>
  <p>We use JavaScript to trigger the modal and to display the current image inside the modal when it is clicked on. Also note that we use the value from the image's "alt" attribute as an image caption text inside the modal.</p>

  <img id="myImg3" class="myImg" src="img_snow.jpg" alt="Snow" style="width:100%;max-width:300px">

  <!-- The Modal -->
  <div id="myModal3" class="modal">
    <span class="close">&times;</span>
    <img class="modal-content" id="img03">
    <div id="caption3" class="caption"></div>
  </div>
</div>

<div id="About" class="tabcontent">
  <h3>About</h3>
  <p>Who we are and what we do.</p>
</div>