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Code Scanner

This page describes the properties of the Code Scanner widget, which is used for scanning barcodes and QR codes.

Building a Self-Checkout Payment System with Code Scanner Widget

The following formats for QR and barcodes are supported:

1D product1D industrial2D
UPC-ACode 39QR Code
UPC-ECode 128Data Matrix
EAN-8ITFAztec
EAN-13RSS-14PDF 417

Content properties​

These properties are customizable options present in the property pane of the widget, allowing users to modify the widget according to their preferences.

Basic​

Scanner layout​

Determines the visual appearance and behavior of the code scanner widget.

Options:

  • Always On: The code scanner widget is always active and ready for scanning.
  • Click to Scan: The code scanner widget acts as a button that is activated only when clicked by the user.

Text string​

Specifies the label text displayed alongside the scanning widget. This property is only available when the Scanner layout is selected as Click to Scan.

General​

Visible boolean​

Controls the visibility of the widget. If you turn off this property, the widget is not visible in View mode. Additionally, you can use JavaScript by clicking on JS next to the Visible property to control the widget's visibility conditionally.

For example, if you want to make the widget visible only when the user checks an item in a Checkbox widget, you can use the following JavaScript expression in the visible property of the Code Scanner widget:

{{Checkbox1.isChecked}}

Disabled boolean​

Prevents users from selecting the widget. Even though the widget remains visible, user input is not permitted. Additionally, you can use JavaScript by clicking on JS next to the Disabled property to control the widget's disabled state conditionally.

For example, if you want to allow only a specific user to interact with the Code Scanner widget, you can use the following JavaScript expression: 

{{appsmith.user.email=="john@appsmith.com"?false:true}}

Animate Loading boolean​

Controls whether the widget is displayed with a loading animation. When enabled, the widget shows a skeletal animation during the loading process. Additionally, you can control it through JavaScript by clicking on the JS next to the property.

Tooltip string​

Sets a tooltip that appears when the user hovers over the widget. It enables you to add hints or provide additional information for the button. The icon properties are only available for the Click to Scan Scanner layout option.

Events​

When an event is triggered, these event handlers can execute queries, JS code, or other supported actions.

onCodeDetected​

Triggered when a valid code is detected.

Style properties​

Style properties allow you to change the look and feel of the button.

Icon​

The icon properties are only accessible for the Click to Scan Scanner layout option.

Select icon string​

Specifies the icon to be displayed on the widget. Additionally, you can use JS to dynamically set the icon. You can refer to the documentation of blueprintjs to explore a wide range of available icons.

Position string​

This property allows you to configure the Icon's placement.

Options:

  • Left: Aligns the icon to the left side of the Text.
  • Right: Aligns the icon to the right side of the Text.

Placement string​

Determines the spacing between the Icon and the Text.

Options:

  • Start: The icon and text appear on the leftmost side of the button.
  • Between: The icon and text appear at opposite ends of the button's space.
  • Center: The icon and text appear in the center of the button space.

This property can be dynamically set using JavaScript by providing a string value of START, CENTER, or BETWEEN.

Color​

Button color string​

Represents the color of the button, specified as a CSS color value. Additionally, the font color can be programmatically modified using JavaScript functions.

Border and shadow​

Border radius string​

Applies rounded corners to the outer edge of the widget. If JavaScript is enabled, you can specify a valid CSS border-radius to adjust the radius of the corners.

Box Shadow string​

This property adds a drop shadow effect to the frame of the widget. If JavaScript is enabled, you can specify valid CSS box-shadow values to customize the appearance of the shadow.

Reference properties​

Reference properties enable you to access the widget's data and state using the dot operator in other widgets or JavaScript functions. They provide additional information or allow interaction with the widget programmatically. For instance, to retrieve the visibility status of a Select widget, you can use CodeScanner1.isVisible.

isDisabled boolean​

It reflects the state of the widget's Disabled setting. It is represented by a boolean value, where true indicates that the widget is disabled, and false indicates that it is enabled for user interaction.

Example:

{{Select1.isDisabled}}

isVisible boolean​

The isVisible property indicates the visibility state of a widget, with true indicating it is visible and false indicating it is hidden.

Example:

{{Select1.isVisible}}

value string​

Retrieves the scanned code value from the widget.

Example:

{{CodeScanner1.value}}

Methods​

Widget property setters enable you to modify the values of widget properties at runtime, eliminating the need to manually update properties in the editor.

These methods are asynchronous and return a Promise. You can use the .then() block to ensure the execution and sequencing of subsequent lines of code in Appsmith.

setVisibility (param: boolean): Promise​

Sets the visibility of the widget.

Example:

CodeScanner1.setVisibility(true)

setDisabled (param: boolean): Promise​

Sets the disabled state of the widget.

Example:

CodeScanner1.setDisabled(false)