A number of field types allow a set number of characters to be entered, for example, text area and long text area. A useful addition to the user interface for these fields is a mechanism to inform the user how many more characters they may enter.
In this recipe we will create a Visualforce page that allows a user to create a case. The subject standard field can contain a maximum of 255 characters. A counter of the number of characters remaining is displayed beneath the Subject input field. The character counter is updated when the user types a character, or if they cut or paste information from or to the field.
This recipe uses the jQuery (http://jquery.com/) JavaScript framework to handle the client-side events. The JavaScript file is included from the Google Hosted Libraries content delivery network rather than being uploaded as a Salesforce static resource, as this makes it straightforward to move to a new version simply by changing the URL of the included...