How can you generate a slug-url using javascript in an input field from a title field?

To generate a slug URL from a title field using JavaScript, you can use the following steps:

1. Retrieve the value of the title field using the value property of the title field's DOM element.
2. Convert the title to a slug by replacing all spaces and special characters with hyphens and converting all characters to lowercase.
3. Set the value of the input field to the generated slug.

Here's an example code snippet that shows how to do this

const titleField = document.getElementById('title');

const slugField = document.getElementById('slug');

titleField.addEventListener('input', function() {

  const title = titleField.value;

  const slug = title.toLowerCase().replace(/[^a-zA-Z0-9]+/g, '-').replace(/^-+|-+$/g, '');

  slugField.value = slug;

});

and the HTML code that goes along with the JavaScript code

<label for="title">Title:</label>

<input type="text" id="title" name="title">

<label for="slug">Slug:</label>

<input type="text" id="slug" name="slug">

In this example, we first retrieve the DOM elements for the title field and the slug field. We then add an event listener to the title field that listens for input events. When the user types in the title field, the event listener retrieves the value of the title field and generates a slug from it. Finally, the event listener sets the value of the slug field to the generated slug.

In this example, we have two input fields, one for the title and one for the generated slug. The for attribute on the label elements specifies which input field they are associated with, and the id attribute on the input fields provides a unique identifier for each field.

Note that the name attributes on the input fields are not strictly necessary for generating the slug, but they are often used in form submissions to identify the data being sent.

Also, we will look at the slug generating part,

const slug = title.toLowerCase().replace(/[^a-zA-Z0-9]+/g, '-').replace(/^-+|-+$/g, '');

This line of code generates a slug from the title string by performing two operations:

• Converting the string to lowercase: title.toLowerCase()

This method is used to make sure that the generated slug only contains lowercase letters.

• Replacing all non-alphanumeric characters with hyphens: title.toLowerCase().replace(/[^a-zA-Z0-9]+/g, '-')

This method uses a regular expression to match all characters that are not letters or numbers ([^a-zA-Z0-9]) and replaces them with hyphens ('-'). The g flag is used to perform a global search and replace, meaning that all matches in the string will be replaced.

• Removing leading and trailing hyphens: title.toLowerCase().replace(/[^a-zA-Z0-9]+/g, '-').replace(/^-+|-+$/g, '')

This method uses another regular expression to remove any leading or trailing hyphens that may have been added as a result of the previous replacement operation. The regular expression ^-+|-+$ matches one or more hyphens at the beginning (^-+) or end (-+$) of the string, and replaces them with an empty string.

So, for example, if the title is "The Quick Brown Fox! 123", the generated slug will be "the-quick-brown-fox-123". This slug can then be used in a URL to identify the resource associated with the title.