Một thú vị, nhưng phần nào hạn chế tập hợp các tính năng có sẵn là cài đặt các phần mở rộng và chủ đề toàn cầu. Các tùy chọn này là tùy chọn dòng lệnh sau khi Firefox đã được cài đặt, do đó họ lựa chọn Firefox và không cài đặt các tùy chọn tập tin. | 342 Part VI Creating Extensions and Themes When this preference is set to true Firefox displays JavaScript warnings in the JavaScript Console. A warning usually means that you are doing something illegal or nonstandard in your code and that might cause unexpected behavior or other problems. It is always recommended to solve all such problems before releasing your extension. Enabling this preference causes all the warnings not only those originating in your extension to be reported to the JavaScript Console. Many extensions have warnings in their code and having several such extensions installed while trying to debug your own code might make finding only the relevant warnings difficult. You should set this preference to true if you want to use the dump function to print messages to the standard console. More information on this appears later in this chapter. As with other preference settings you can type about config in your Firefox address bar and use the Preferences window to create new preferences and modify the existing ones. Other methods for setting preferences such as modifying the file will also work. Logging Logging is a simple but very efficient method for debugging your code. Printing the values of your variables the received messages return codes and so on can help you figure out where the problem is and how it can be solved. Logging can also be used to report major events and errors in your application and looking at these messages can help you make sure that the application is actually doing what you expect it to do. There are several logging mechanisms in Mozilla Standard Console You can use the dump function to print messages to the standard console. Similar to the alert function dump expects a single string argument. By default the standard console is disabled in Firefox. To enable it set the value of the preference to true and start Firefox with the .
