LESS - Import Options Once Keyword

Quiz

Description

The @import (once) keyword ensures that the file is imported only once and any following import statements will be neglected for that file. This is the default behavior of the @import statements. This was released in version 1.4.0.

Example

The following example demonstrates the use of once keyword in the LESS file −

<html>
   <head>
      <link rel = "stylesheet" href = "style.css" type = "text/css" />
      <title>Import Options Once</title>
   </head>

   <body>
      <h1>Welcome to Tutorialspoint</h1>
      <p class = "para_1">LESS is a CSS pre-processor that enables customizable, 
      manageable and reusable style sheet for web site.</p>
      <p class = "para_2">LESS is a CSS pre-processor that enables customizable, 
      manageable and reusable style sheet for web site.</p>
   </body>
</html>

Now, create the style.less file.

style.less

@import (once) "http://www.tutorialspoint.com/less/once.less";
@import (once) "http://www.tutorialspoint.com/less/once.less"; // this statement will be ignored
.para_1 {
   color: red;
   .style;
}

.para_2 {
   color: blue;
}

The following code will import the once.less file into style.less from the https://www.tutorialspoint.com/less/once.less path −

once.less

.style {
   font-family: "Comic Sans MS";
   font-size: 20px;
}

You can compile the style.less to style.css by using the following command −

lessc style.less style.css

Execute the above command; it will create the style.css file automatically with the following code −

style.css

.style {
   font-family: "Comic Sans MS";
   font-size: 20px;
}

.para_1 {
   color: red;
   font-family: "Comic Sans MS";
   font-size: 20px;
}

.para_2 {
   color: blue;
}

Output

Follow these steps to see how the above code works −

Save the above html code in the import_options_once.html file.
Open this HTML file in a browser, the following output will get displayed.

less_import_options.htm

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