How to set a multiplier to scale by in the URL string of IText object using FabricJS?

In this tutorial, we are going to learn about how to set a multiplier to scale by in the URL string of IText object using FabricJS. The IText class was introduced in FabricJS version 1.4, extends fabric.Text and is used to create IText instances. An IText instance gives us the freedom to select, cut, paste or add new text without additional configurations. There are also various supported key combinations and mouse/touch combinations which make text interactive which are not provided in Text.

Textbox, however, which is based on IText allows us to resize the text rectangle and wraps lines automatically. This is not true for IText as height is not adjusted based on the wrapping of lines. We can manipulate our IText object by using various properties. Likewise, we can set a multiplier to scale by in the URL string of IText object by using the multiplier property.

Syntax

toDataURL({ multiplier: Number }: Object): String

Parameters

  • options (optional) − This parameter is an Object which provides additional customizations to the URL representation of the IText object. Using this parameter height, quality, format and a lot of other properties can be changed of which multiplier is a property.

Options Keys

  • multiplier − This property accepts a Number value which denotes the multiplier to scale the final IText output image by. The default value is 1.

Example 1

Without using the multiplier property

Let’s see a code example to see the output image when the multiplier property is not used. As soon as we open the console from the dev tools, we can see the URL representation of the IText object. We can copy that URL and paste it into the address bar of a new tab to see the final output. Since we have not used the multiplier property, the default multiplier value will be used, which is 1.

<!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>Without using the multiplier property</h2>
   <p>You can open console from dev tools and see the output URL. You can copy that and paste it in the address bar of a new tab to see that the image</p>
   <canvas id="canvas"></canvas>

   <script>
      // Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas");
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);

      // Initiate a shadow object
      var shadow = new fabric.Shadow({
         blur: 25,
         color: "grey",
         offsetX: 12,
         offsetY: 15,
      });

      // Initiate an itext object
      var itext = new fabric.IText(
         "Add sample text here.
Lorem ipsum dolor sit amet 
consectetur adipiscing.",{
            width: 300,
            left: 310,
            top: 70,
            fill: "#c70039",
            backgroundColor: "#c1dfed",
            stroke: "#c70039",
            originX: "center",
            shadow: shadow,
         }
      );

      // Add it to the canvas
      canvas.add(itext);

      // Using the toDataURL method
      console.log(itext.toDataURL());
   </script>
</body>
</html>

Example

Using the multiplier property

Let’s see a code example to see how the final output image of the IText object looks like when the multiplier property is used. In this case, we passed it a value of 2. Therefore the final image will be scaled by twice in both x and y directions.

<!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 multiplier property</h2>
   <p>You can open console from dev tools and see the output URL. You can copy that and paste it in the address bar of a new tab to see the final image </p>
   <canvas id="canvas"></canvas>

   <script>
      // Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas");
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);

      // Initiate a shadow object
      var shadow = new fabric.Shadow({
         blur: 25,
         color: "grey",
         offsetX: 12,
         offsetY: 15,
      });

      // Initiate an itext object
      var itext = new fabric.IText(
         "Add sample text here.
Lorem ipsum dolor sit amet 
consectetur adipiscing.",{
            width: 300,
            left: 310,
            top: 70,
            fill: "#c70039",
            backgroundColor: "#c1dfed",
            stroke: "#c70039",
            originX: "center",
            shadow: shadow,
         }
      );

      // Add it to the canvas
      canvas.add(itext);

      // Using the toDataURL method
      console.log(itext.toDataURL({ multiplier: 2 }));
   </script>
</body>
</html>

Updated on: 13-Sep-2022

279 Views

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