Fabric.js | Rect dirty Property

In this article, when we set the dirty property to true then the object cache will be rerendered next render call to canvas rectangle using FabricJS. The canvas rectangle means rectangle is movable and can be stretched according to requirement. Further, the rectangle can be customized when it comes to initial stroke color, height, width, fill color, or stroke width.

Approach: To make it possible, we are going to use a JavaScript library called FabricJS. After importing the library, we will create a canvas block in the body tag which will contain the rectangle. After this, we will initialize instances of Canvas and Rectangle provided by FabricJS and set the dirty property of canvas rectangle and it will render the Rectangle on the Canvas as given in the below example.

Syntax:

fabric.Rect({
    width: number,
    height: number,
    dirty: Boolean
});

Parameters: This function accepts three parameters as mentioned above and described below:

width: It specifies the width of rectangle.
height: It specifies the height of rectangle.
dirty: It specifies the object cache will be rerendered next render call or not.

Example: This example uses FabricJS to set the dirty property on canvas rectangle as given below.

<!DOCTYPE html>  

<html>  

<head>  

    <title>  

        Fabric.js | Rect dirty Property 

    </title>  

    <!-- Adding the FabricJS library -->

    <script src=  

"https://cdnjs.cloudflare.com/ajax/libs/fabric.js/3.6.2/fabric.min.js">  

    </script>  

</head>  

<body>  

    <canvas id="canvas" width="600" height="200"

        style="border:1px solid #000000">  

    </canvas>  

    <script>  

        // Initiate a Canvas instance  

        var canvas = new fabric.Canvas("canvas");  

        // Initiate a Rect instance  

        var rectangle = new fabric.Rect({  

            width: 200, 

            height: 100, 

            fill: '',  

            stroke: 'green', 

            strokeWidth: 3, 

            cornerStyle: 'circle', 

            dirty: false 

        });  

        // Render the Rect in canvas  

        canvas.add(rectangle);  

        canvas.centerObject(rectangle); 

    </script>  

</body>  

</html>

Output:

Article Tags :

JavaScript

Web Technologies

Fabric.js