RIOT.JS - Expressions

RIOT js uses {} to define expressions. RIOT js allows following types of expressions.

  • Simple Expression − Define a variable and use within a tag.

<customTag>
   <h1>{title}</h1>
   <script>
      this.title = "Welcome to TutorialsPoint.COM";
   </script>
</customTag>

  • Evaluate Expression − Evaluate a variable when use in an operation.

<customTag>
   <h2>{val * 5}</h2>
   <script>
      this.val = 4;
   </script>
</customTag>

  • Get value from Options object − To get the value passed to tag via attributes.

Example

Following is the complete example of above concepts.

customTag.tag

<customTag>
   <h1>{title}</h1>
   <h2>{val * 5}</h2>
   <h2>{opts.color}</h2>
   <script>
      this.title = "Welcome to TutorialsPoint.COM";
      this.val = 4;
   </script>
</customTag>

index.htm

<!DOCTYPE html>
<html>
   <head>
      <script src = "https://cdnjs.cloudflare.com/ajax/libs/riot/3.13.2/riot+compiler.min.js"></script>
   </head>
   <body>
      <customTag color="red"></customTag>
      <script src = "customTag.tag" type = "riot/tag"></script>
      <script>
         riot.mount("customTag");
      </script>
   </body>
</html>

This will produce following result −

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