Thiết kế web với joomla 1.6(5).x part 8 docx

Part I: Getting Started with Joomla! 60 Using the System Tab The System tab includes a number of important controls that enable you to specify the conditions relating to user registration, the permissible file types for uploads to your system, and the cache and session settings. The System tab of the Global Configuration Manager is accessed by clicking on the text link labeled System, on the top left side of the page. Figure 4.2 shows the workspace of the System tab. FIGURE 4.2 The System tab of the Global Configuration Manager in Joomla 1.5.x. The workspace of the System tab is broken into six areas; each area is discussed in the following sections. System settings The system settings are largely populated automatically by your Joomla! system. Several of these values cannot, or should not be changed. Chapter 4: Getting the Most from Site Configuration 61 l Secret Word: The Secret Word is unique to every Joomla! site and is used by the system as the basis for creating tokens and for encrypting user passwords. The Secret Word is auto- matically created by the system during installation. This cannot be changed. l Path to Log folder: This field shows the location of the log files on your server. This information is supplied automatically by Joomla! during installation. l Enable Web Services: Click Yes to enable Remote Procedure Calls (RPC) using HTTP and XML. There is no need to change this setting unless it is specifically called for by a third party extension. The default value is No. l Help Server: The URL of the site used to supply the information your administrators see when they click on the Help icons in the admin interface. By default this is set to the offi- cial Joomla! site. User settings The settings in this area of the workspace relate to the ability of users to register on your site and are only relevant if your site does permit user registration from the front end. The settings are: l Allow User Registration: Click Yes to allow site visitors to apply to become registered users of your site. Note that you must have the user registration form published for public visitors or there is no point in enabling this option. The default value is Yes. l New User Registration Type: Select from the combo box the level that you want assigned automatically to new users. This selection can always be overridden on a case-by- case basis by the site administrator through the User Manager. The options here are lim- ited to Registered, Author, Editor, and Publisher. The default value is Registered. l New User Account Activation: Set this value to Yes to require the system to send all new users a confirmation e-mail that the user must act upon to validate and activate his account; until the user validates the account, it cannot be used. Setting this to No means that user accounts will be immediately active without the need for the user to take further action. The default value is Yes. l Front-end User Parameters: Set to Show to permit users to set certain preferences that are specific to their account. The options include the ability to set preferences for lan- guage, editor, and help site. This is only applicable to registered users and the options will only be available on the user’s page. The default value is Show. Cross-Reference Managing users and user registration is discussed in more detail in Chapter 10. Media settings The controls in this section relate to the permissible and forbidden file types for your system. These limitations apply to yours, or your users’, ability to upload new files to the system for use in Part I: Getting Started with Joomla! 62 the content and components of your site. The controls in this area also allow you to specify the location where the uploaded files will be stored. You can adjust the following settings: l Legal Extensions (File Types): The field contains a list of permitted file types, shown by their extensions. You can add new types or delete existing ones. The default values are: bmp, csv, doc, epg, gif, ico, jpg, odg, odp, ods, odt, pdf, png, ppt, swf, txt, xcf, and xls. l Maximum Size (in bytes): Sets a limit on the size of files that can be uploaded. The value is expressed in bytes. The default value is 100,000,000 — that is, 100 MB. l Path to Media Folder: Shows the destination for all uploaded nonimage media files. You can change this to whatever path you prefer. The default value is images. l Path to Image Folder: Shows the destination for all uploaded image files. You can change this to whatever path you prefer. The default value is images/stories. Caution You can set alternative paths for either the media or the image files, but do not move the system-created images directory or the files or directories that are located inside the images folder. The system needs files located inside those directories, and moving them will break the links to those files. l Restrict Uploads: When set to Yes, this imposes the restrictions on the file uploads. The default setting is Yes. l Check MIME Types: Leave this set to Yes to have the system check the file’s MIME type against the filenames to make sure that what is actually being uploaded is what the name says it is. The default setting is Yes. l Legal Image Extensions (File Types): The field contains a list of permitted image file types, shown by their extensions. You can add new types or delete an existing one. The default values are: bmp, gif, jpg, and png. l Ignored Extensions: Enter here the extensions of any files you want to exempt from restrictions, including the confirmation of MIME type. By default, no file types are exempted. l Legal MIME Types: By default, this field contains a list of permitted file extensions with their related MIME types. The default values are image/jpeg, image/gif, image/png, image/ bmp, application/x-shockwave-flash, application/msword, application/excel, application/ pdf, application/powerpoint, text/plain, and application/x-zip. l Illegal MIME Types: Contains a list of the blocked MIME types. The default value is text/ html. l Enable Flash Uploader: Set to Yes to enable the Flash Uploader in the Media Manager. The Flash Uploader allows you to easily upload multiple files at one time. The default value is No. Joomla! 1.6 Joomla! 1.6 includes an additional option here: Minimum User Level for Media Manager. The combo box con- tains a list of the user groups on the site and allows you to restrict the use of the Media Manager to only those users who belong to the selected group, or higher. Chapter 4: Getting the Most from Site Configuration 63 Cross-Reference The Media Manager is discussed in detail in Chapter 6. Debug settings You can use the Debug Settings during development or if you are having problems with your site. The settings should not be enabled for a live site, because the output will be visible to site visitors at the bottom of the pages. This section only includes two options: l Debug System: Set to Yes to enable the debugging system. The tool provides you with diagnostic information as well as language translations and the output of SQL errors. By default this is set to No. l Debug Language: Set to Yes to enable debugging of language files. This control does not work unless the preceding control, Debug System, is set to Yes. By default this is set to No. Cache settings Use these controls to enable and configure the system-wide caching. The options available here include the following: l Cache: Set this to Yes to enable systemwide caching. l Cache Time: Type an integer value to set the number of minutes that the cache contents are kept before being dumped and refreshed. The default value is 15 minutes. This setting is dependent upon the control above, Cache, being set to Yes. l Cache Handler: This setting has only one option, so there are no options here for you to set. Session settings The Session settings enable you to choose how to handle a logged-in, but inactive, user. The two controls are: l Session Lifetime: Set an integer value to specify the number of minutes the user can be inactive before the system forces them to log out. The default value is 15 minutes. l Session Handler: Select from the combo box how the session data will be maintained. The default setting is Database. Note Longer session values are more convenient for the users and the administrator, but excessively long values can be a security threat to your site, as they open up the possibility that a user who does not log out properly will leave an active open session which might be used by an unauthorized user. During development, however, very long session times are extremely convenient when working on the site contents. Part I: Getting Started with Joomla! 64 Managing Server Tab Options The Server Tab provides a collection of settings that relate to the way your system interacts with the server upon which is it hosted. Settings here cover not only the web server, but also the Database, FTP, and Mail systems. The Server tab of the Global Configuration Manager is accessed by clicking on the text link labeled Server, on the top-left side of the page. Figure 4.3 shows the workspace. FIGURE 4.3 The Server tab of the Global Configuration Manager. The workspace of the Site tab is broken into five areas; each area is discussed in the following sections. Server settings The following settings discussed relate to your general server configuration. l Path to Temp-folder: This field shows the path to the directory where the system’s tem- porary files are kept. The value for this field is created automatically by Joomla! during installation. Chapter 4: Getting the Most from Site Configuration 65 l GZIP Page Compression: Set this to Yes if your server supports GZIP page compression. Doing this improves site performance, but note that it only works if this feature is pro- vided by your server. l Error Reporting: Select a value from the combo box to set the level of error reporting you want the system to use. The options available are System Default, None, Simple, and Maximum. The default setting is System Default, which allows the level of error reporting to be determined by the settings in the server’s php.ini file. Note The output from the error reporting is displayed at the bottom of all pages and is visible to both front-end and back-end users. l Force SSL: Choose from the combo box to select whether the system requires the use of SSL for connections. The options are None, Administrator Only, and Entire Site. The default is None. Note that this control depends upon whether your server supports SSL. Locale settings The Locale setting allows you to adjust the time settings to suit your site, regardless of the server’s default time setting — Time Zone: Select your preferred time zone from the combo box. FTP settings Joomla! has a built-in FTP function that will assist you with moving files to the server without hav- ing to resort to a third party piece of software. The settings in this area of the workspace allow you to set up this feature. If you wish to use traditional FTP or your web site file manager, there is no reason to enable the following: l Enable FTP: Set to Yes to use Joomla’s FTP function. l FTP Host: Type the FTP URL of the host server. There is likely to be a value already in this field; it is Joomla’s best guess at the proper FTP URL and is likely to be correct. l FTP Port: Type an integer value for the port number where FTP is accessed. The default value is 21. l FTP Username: Type the username that Joomla! can use to access the server via FTP. l FTP Password: Type the password that goes with the FTP username. l FTP Root: Type the name of the directory where the files should be uploaded. Database settings The values in the fields in the Database Settings area are initially created during the installation of your site. The information in this section should not be modified, except under exceptional cir- cumstances, for example, moving your site to a new server. The fields provided are: . swf, txt, xcf, and xls. l Maximum Size (in bytes): Sets a limit on the size of files that can be uploaded. The value is expressed in bytes. The default value is 10 0,000,000 — that is, 10 0 MB. l. files at one time. The default value is No. Joomla! 1. 6 Joomla! 1. 6 includes an additional option here: Minimum User Level for Media Manager. The combo box con- tains a list of the user groups on. png. l Ignored Extensions: Enter here the extensions of any files you want to exempt from restrictions, including the confirmation of MIME type. By default, no file types are exempted. l Legal