Mastering Angular Material Table: Select and Deselect Row on Click

Angular Material is a popular UI component library that helps developers build modern and responsive web applications. One of the essential components is the Angular Material table. In this blog post, we’ll explore how to implement a feature that allows users to select and deselect rows within an Angular Material table by clicking on them.

The Problem

Imagine the following Angular Material table scenario:

The table has a delete icon for each row, and when a user clicks on it, the row should be highlighted. However, when the user clicks on the delete icon again, the row should be deselected. This functionality is not working as expected, and the row does not deselect when clicked again.

Implementing the Solution

1. Modify the TypeScript Function

First, update the highlight() function in your TypeScript code:

highlight(row) {
  if (this.highlightedRows.indexOf(row) > -1) {
    this.highlightedRows.splice(this.highlightedRows.indexOf(row), 1);
  } else {
    this.highlightedRows.push(row);
  }
}

This modification checks if the clicked row exists in the highlightedRows array. If it does, the row is removed from the array (deselected); otherwise, it is added (selected).

2. Alternative Solution: Use a Highlight Object

Another approach is to use an object instead of an array to store the toggle state of each row. This can be done using a unique row value (e.g., row ID or name) as the key. For example:

<mat-row 
  *matRowDef="let row; columns: displayedColumns;"
  (click)="highlightedRows[row.name]  = !highlightedRows[row.name] 
"
  [style.background] ="highlightedRows[row.name] 
 ? 'lightblue' : ''">
</mat-row>

This code snippet toggles the row’s background color based on the state of the highlightedRows object.

Best Practices for Angular Material Tables

• Consistent Naming and Formatting: Use a consistent naming convention for variables, functions, and components. This will make your code easier to read and maintain.
• Documentation: Comment your code to explain the purpose of different components, functions, and variables. This will help others understand your code and make it easier to maintain.
• Test Your Code: Test your application regularly to ensure that all features are working as expected. This will help you identify and fix issues before they become bigger problems.

Conclusion

Implementing the select and deselect functionality in Angular Material tables can be achieved using a few simple modifications to your TypeScript and HTML code. By following the solutions provided in this blog post, you’ll be able to create a more interactive and user-friendly table experience for your web application. Keep experimenting and exploring the Angular Material library to discover more ways to enhance your applications!