How to create a String representation of an Image object using FabricJS?

FabricJS Javascript HTML5 Canvas

In this tutorial, we are going to show how you can create a String representation of an Image object using FabricJS. We can create an Image object by creating an instance of fabric.Image. Since it is one of the basic elements of FabricJS, we can also easily customize it by applying properties like angle, opacity etc. In order to create a String representation of an Image object, we use the toString method.

Syntax

toString(): String

Using the toString method

Example

Let’s see a code example to see the logged output when the toString method is used. In this case, a String representation of the image instance will be returned.


<!DOCTYPE html>
<html>
<head>
   <!-- Adding the Fabric JS Library-->
   <script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
</head>
<body>
   <h2>Using the toString method</h2>
   <p>
      You can open console from dev tools and see that the logged output contains the String representation of the image instance
   </p>
   <canvas id="canvas"></canvas>
   <img
      src="https://www.tutorialspoint.com/images/logo.png"
      id="img1"
      style="display: none"
   />
   <script>
      // Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas");
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);
      
      // Initiating the image element
      var imageElement = document.getElementById("img1");
      
      // Initiate an Image object
      var image = new fabric.Image(imageElement, {
         top: 50,
         left: 110,
      });
      
      // Add it to the canvas
      canvas.add(image);
      
      // Using the toString method
      console.log(
         "String representation of the Image instance is: ",
         image.toString()
      );
   </script>
</body>
</html>

Using toString method to compare two different elements

Example

Let’s see a code example to see how we can compare two objects by viewing their respective String representations. Here, we have initialized an Image instance and a rectangle instance. On applying the toString method on each of them we can see their respective string representations in the console.


<!DOCTYPE html>
<html>
<head>
   <!-- Adding the Fabric JS Library-->
   <script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
</head>
<body>
   <h2>Using toString method to compare two different elements</h2>
   <p>
      You can open console from dev tools and see that the logged output contains the String representation of the Image instance and the rectangle instance
   </p>
   <canvas id="canvas"></canvas>
   <img src="https://www.tutorialspoint.com/images/logo.png" id="img1" style="display: none" />
   <script>
      // Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas");
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);
      
      // Initiating the image element
      var imageElement = document.getElementById("img1");
      
      // Initiate an Image object
      var image = new fabric.Image(imageElement, {
         top: 50,
         left: 110,
      });
      
      // Initiate a Rectangle object
      var rect = new fabric.Rect({
         stroke: "red",
         strokeWidth: 20,
         width: 20,
         height: 50,
         left: 460,
         top: 55,
      });
      
      // Add them to the canvas
      canvas.add(image);
      canvas.add(rect);
      
      // Using the toString method
      console.log(
         "String representation of the Image instance is: ",
         image.toString()
      );
      console.log(
         "String representation of the Rectangle instance is: ",
         rect.toString()
      );
   </script>
</body>
</html>

Conclusion

In this tutorial, we used two examples to demonstrate how you can create a String representation of an Image object using FabricJS.

Rahul Gurung

Updated on: 26-Oct-2022

231 Views

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