How to store data into DOM?-JS Tutorial-php.cn

How to store data into DOM?

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Release： 2023-09-14 23:41:11

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如何将数据存储到 DOM 中？

Storing data in the DOM means storing data in plain text format. For example, we store data in state variables while using React or any other reactive framework. When the user updates the data in the input field, it stores the updated data in the state variable.

So we store the data in the state variable before submitting the form. When the form is submitted, we use the value of the state variable.

In plain JavaScript we can do the same thing like store data in plain text format and whenever we need to submit a form we can get the data from the DOM instead of the input field.

Here, we will learn to store data in DOM using JavaScript and Jquery.

Use JavaScript to store data in the DOM

In JavaScript, we can create an object to store data. We can store data in an object in plain text format and get it from the object when needed.

grammar

Users can use JavaScript to store data in the DOM according to the following syntax.

let data_obj = {
   prop1: "",  
}
data_obj.prop1 = value;

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In the above syntax, we create the data_obj object to store data, and we can update its value.

Example

In the example below, we create a form with two input fields. Additionally, we gave each input field a name. Whenever the user clicks on the store data function, it calls the storeInDOM() function, which takes the input value and stores it in the object. Whenever the user presses the "Get Stored Data" button, it calls the getFromDOM() function, which accesses the data from the data_obj object.

<html>
<body>
   <h2>Using JavaScript to store data in DOM</h2>
   <form>
      <label for = "fname"> First name: </label> <br>
      <input type = "text" id = "fname" name = "fname"> <br>
      <label for = "lname"> Last name: </label> <br>
      <input type = "text" id = "lname" name = "lname">
   </form>
   <button onclick = "storeInDOM()"> Store data </button>
   <button onclick = "getFromDOM()"> get stored data </button>
   <div id = "content"> </div>
   <script>
      let data_obj = {
         fname: "",
         lname: ""
      }
      function storeInDOM() {
         var fname = document.getElementById("fname").value;
         var lname = document.getElementById("lname").value;
         data_obj.fname = fname;
         data_obj.lname = lname;
      }
      function getFromDOM() {
         document.getElementById("content").innerHTML = "The value of first name is - " + data_obj.fname + " <br> The value of the second name is - " + data_obj.lname;
      }
   </script>
</body>
</html>

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In the output, the user can see the stored data.
Using jQuery to store data in the DOM

jQuery contains a data API, which we can call using the data() method. We can store data for specific elements. When we pass two parameters to the data API, it stores the data for the specific element; otherwise, it returns the data stored for the specific element.

grammar

Users can use Jquery's data() method to store data in the DOM according to the following syntax.

$("CSS_identifier ").data("key_name", value);

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CSS identifiers are used to select elements in the above syntax. The data() method takes the key as the first parameter and the related value as the second parameter.

Example

The form contains the email and password input fields as in the example below. Whenever the user presses the button to store the data, we use Jquery to get the value entered and store it in the DOM of the specific element using the data() method. Here, $("#email").data("email", email) will access the input with id equal to email and store 'email' as the key and the input value as the value of the 'email' key.

Therefore, we can use the data() method to store key-value pairs with any element as a reference, and users also need to use the same element as a reference when accessing the data.

<html>
<head>
   <script src = "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.6.3/jquery.min.js"></script>
</head>
<body>
   <h2>Using  jQuery to store data in DOM</h2>
   <form>
      <label for = "Email"> Email: </label> <br>
      <input type = "email" id = "email" name = "email"> <br>
      <label for = "password"> Password: </label> <br>
      <input type = "text" id = "password" name = "password">
   </form>
   <button onclick = "storeInDOM()"> Store data </button>
   <button onclick = "getFromDOM()"> Show stored data </button>
   <div id = "content"> </div>
   <script>
      // storing data in DOM using jQuery's data() method
      function storeInDOM() {
         var email = $("#email").val();
         var password = $("#password").val();
         $("#email").data("email", email);
         $("#password").data("password", password);
      }
      // getting data from DOM using jQuery's data() method
      function getFromDOM() {
         var email = $("#email").data("email");
         var password = $("#password").data("password");
         $("#content").html("Email: " + email + " Password: " + password);
      }
   </script>
</body>
</html>

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Users learned to store data in the DOM. However, storing data in the DOM is a bad practice because it is temporary. Users can use the browser's local or session storage to store data, and the syntax is simple.

In JQuery, users can use the data API to store data for specific elements. In JavaScript, users need to store all data in single or multiple objects.

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