THIS chapter describes the World Wide Web and the component of the ANT Internet Suite, Fresco®, which enables you to browse it.
The World Wide Web is a widely-used feature of the Internet. Computers linked to the Internet (Web sites) hold collections of hypertext pages, each containing links to other page of related information on other servers. Pages can contain text and graphics, links to other pages, and also links to other Internet facilities including email addresses, newsgroups and FTP sites.
Who is on the Web?
There are sites for all kinds of places, institutions, organisations and companies across the Web.
As with email, a printed Web directory book or magazine will contain the addresses of some sites to try out, but exploring for yourself is a good way to find new sites. There are other sources of Web addresses:
How the Web works
When you click on a link, the address it contains (known as a uniform resource locator or URL) is triggered, and your computer connects to the requested address and downloads the page, including text and graphics, from the web server at that address.
Moving from page to page, and site to site, in this way is called browsing and so programs like Fresco are known as Web browsers.
You can also access other Internet facilities such as mail, FTP and Gopher searches using Fresco.
To start up Fresco, double-click on the Web icon in the Internet panel, then click Select on the Fresco icon on the icon bar.
All work with Fresco takes place inside the Fresco window, which displays Web pages and includes buttons and other controls. The first time you start Fresco, it loads a welcome page from the disc, including a link to the ANT web site. Follow this link and you will be able to register your software online.
The Fresco window
Jumping from link to link
Links are usually shown as different coloured, or underlined, text. Graphics can also be links: if a graphic is a link it may have a border the same colour as the colour used for text links, and you will see an address at the bottom of the window when you point to it.
To jump to the page shown by a link:
1 Point to the link text or graphic.
The URL contained in the link will appear at the bottom of the Fresco window, for example:
Link to http://www.riscos.com/
The pointer will change shape to a pointing hand whenever the it is over any clickable objects such as links on a page.
2 Click on the link text or graphic in the Fresco window.
Fresco will attempt to contact that computer and retrieve and display the page.
3 The globe icon will revolve and a series of messages will appear at the bottom of the window:
Connecting to remote host
Waiting for response from remote host
Receiving data from the remote host
Image fetching complete
4 As these messages appear, the page will be displayed. You can usually monitor progress by checking how many bytes have been downloaded and how large the page is in total.
Returning to pages viewed in a session
As you move from page to page, Fresco stores details of the pages accessed in a History list. You can use this to:
Adjust-click the Back button to return to the first page you displayed in the window.
You can set the home page, the page loaded when you first click on the Fresco icon, in the Files dialogue box accessed from the Choices menu.
Abandoning a fetch
If it seems that a page has stopped fetching, or there is no progress, or a page is larger than you expected and you don't want to wait for it to download, you can stop a fetch.
To stop a page from being fetched:
Opening a named location
You may want to move directly to a particular web page, rather than simply browsing through the web. To do this:
1 Place the caret in the URL line and press Ctrl-U to clear its contents.
2 Type in the URL you want to open, for example:
http://www.riscos.com/
You can use shortcuts to enter some of the address:
3 Press Return. Fresco will attempt to load the page.
Reloading a page
Sometimes a page may fail to load, or the transfer become interrupted. If activity appears to have stalled it is worth clicking the Reload button to start loading the page again.
Reload is also useful to fetch a fresh version of a page which is stored in your cache, for example a news service which is regularly updated
To reload the page you are looking at:
Accessing authenticated sites
Some Web pages require you to create and enter a user ID and password in order to access them. If you return to such a site, a dialogue will be displayed:
Fresco can remember and store these IDs and passwords for you, if you wish.
Viewing images
Most Web pages contain images in a variety of formats. Fresco includes the software needed to display images in most formats in common use, including GIF, JPEG and PNG. Some images are stored in special `progressive' formats so that they can be displayed as they are being loaded: Fresco supports these versions too.
Displaying images can be slow if you have a slow Internet connection. You can choose not to display all images automatically (see Setting display options on page 20-144).
To find out more about any image you see on a web site, such as what format the original file was, and its size:
Searching text within a page
Fresco contains a search facility which enables you to search for text within the page you are currently displaying. This is particularly useful for searching long documents such as FAQs and gopher pages.
To search for text:
You can use the Hotlist facility to access favourite sites.
There will be many sites you want to visit often. You can create a hotlist of these sites so that you can load their URL by clicking on their entry in the list.
To add a site to the hotlist:
To view the hotlist:
To go to a page in the hotlist:
You can also access pages directly from the !Hotlist utility. Click on the entry in the Hotlist and the pages will be loaded by Fresco. See Using Hotlist for details.
If you are using Fresco in a school setting or at home you may wish to restrict access to some sites, or only to allow access to certain authorised sites.
Fresco contains some access control features which enable you to allow or deny access to named sites. If a user attempts to access a URL which is not permitted, a warning message will tell them that they may not access that site.
This feature works by embedding a list of authorised or banned sites in Fresco's config file.
Editing the config file
To set up your list:
You are now ready to add the names of sites to include or exclude to the config file.
Allowing access to named sites
This is the more powerful of the two options though it will severely limit Fresco's capacity for browsing. Only those sites specifically named in Fresco's config file may be accessed. Attempts to access any other URL will be denied.
To set up the file:
To add the file to the Configuration details:
The next time you restart Fresco only the nominated sites will be accessible to users.
Denying access to named sites
This is the less powerful of the two options. Access will only be denied to those sites specifically named in Fresco's config file. Attempts to access any other URL will be allowed.
To set up the file:
To add the file to the Configuration details:
The next time you restart Fresco only the nominated sites will be accessible to users.
You can export information from Fresco in a variety of formats by saving pages as files. You can also save images separately from the pages on which they are stored.
Note that because Web pages have many possible components it is not always possible to save everything.
Saving pages
You can save a copy of the page, either their text contents or their HTML source, on your computer.
You can save pages in four formats:
To save a page:
To save in other formats you will need to:
Saving images
You may save images from Web pages either in their original formats or converted into sprites.
To save an image:
You can print pages directly from Fresco. Printing a page preserves the formatting and graphics.
To print a page:
There are several ways you can customise Fresco to suit your requirements, changing the colours used, the parts of the window displayed, the fonts used, and so forth. You can also change the way Fresco operates by setting up disc caches to store pages locally, or using a proxy server to fetch pages for you.
You can change the configuration options permanently, or just for the current session. So, for example, if you have proxy servers set, you can turn them off for a session but revert to your original settings next time you load the software.
Working with Fresco configuration
To change Fresco configurations on a temporary or permanent basis:
Click OK to make a temporary change which will remain in force for this session only.
Click Reload to reload the original settings.
Setting display options
You can change the way Fresco displays pages using the Display choices dialogue from the Choices option on the icon bar. This changes your default settings for the display of pages and the images they contain.
The Use more colours option enables Fresco to display JPEG and other image formats in greater colour depths (that is, at 16 or 24-bits per pixel), but requires more memory. You should only choose this option if you have a fast computer with plenty of memory and which is capable of displaying 16-bit colour images.
To set your default display choices:
1 Choose Choices... from the Fresco icon menu.
2 Click Display options.
The Display options dialogue will be displayed:
3 Tick the boxes for the default settings you want in the Display options section:
It is recommended that you leave these options switched on.
4 Tick the box to Use more colours to use 16-bit colour for image display where appropriate.
5 Tick Automatically fetch images to download images on a page automatically.
6 Enter the maximum number of image fetches to allow at once.
7 Click Set to save your options.
Fonts
You can choose which fonts you use to display the text on Web pages. You can choose two fonts, the standard font used for most text and headings, and a fixed width (typewriter style) font used by some paragraph and character tags. You can also set the font sizes used to display text.
Colours
You can set the colours used to display each part of web pages, including colours for text, links and page backgrounds, and for rules and parts of forms.
6. When you have set all the colours you want, click Set to return to the Fresco configuration panel.
Files and cache
You can choose any page you like to act as your home page, the page which is displayed when you load Fresco, by entering its URL as your Welcome page.
You can also choose:
The Cache size options limits the amount of hard disc space used by Fresco. Fresco stores copies of web pages you access on your hard disc, and caches them so that next time in a session you look at them it can fetch them from your disc rather than their original site.
To set file and cache options:
Printing options
You can choose several options to customise the way Web pages are printed.
Proxy options
Proxies tells Fresco to use copies of pages stored on servers close to you, and to use the requested servers to fetch pages for you. The advantages of doing this are that the server may already have a copy of the requested page in its cache, and be able to deliver it to you directly, and that the server may be able to access a higher bandwidth route to distant servers and thus fetch the page more quickly.
You can set proxy options separately for HTTP, FTP and Gopher fetches, and turn proxying on and off. You can also exclude certain domains from proxy service, if you know that you can fetch them more efficiently than your chosen proxy server can, such as your pages in own local domain.
For details of suitable proxy servers for you to use, and domains to exclude, contact Technical Support at your service provider.
To set proxy options:
Display settings
You can also change the way Fresco works for the duration of a session using the Display menu. Click Menu inside the Fresco window and choose Display:
You can send mail directly from Fresco. Many pages contain mailto URLs, which contain email addresses. For example, the manager of a Web site may invite your comments and include a mailto address for you to write to.
If you see a mailto URL link and want to send a message:
Web pages can contain links to FTP sites. You can recognise them by their FTP URLs, in the form:
ftp://ftp.demon.net/pub
Downloading files
To download an FTP file:
Entering account names and passwords
If you are downloading files from systems where you have an account or where there is no public access, you will need to enter an account name and password in order to be able to download any files.
Where this is the case, Fresco will display a dialogue for you to enter the required information before you download the file.
You can perform gopher searches direct from Fresco.
What is Gopher?
Gopher is in some ways a predecessor of the Web. It is an index of documents stored on special servers called Gopher servers which can be accessed via the Internet. You can search using keywords or by burrowing through the hierarchy of directories in which the documents are stored.
Using Gopher
Gopher capability is built into Fresco. To access a Gopher site, you simply click on a link. You can recognise Gopher links because they take the form:
gopher://gopher.micro.umn.edu:70/1
Once you reach a gopher site, you can either:
While the World Wide Web is one of the easiest ways to use the Internet, you may occasionally encounter problems accessing a particular page. This section lists some problems and suggests solutions.
A link didn't work or took me to the wrong place
Sometimes links are entered incorrectly by the authors of the web page, so you don't get the results expected. Link addresses may change without the page containing them being updated, so that the link is broken.
I know I've got the address right, but I can't access the page
The server holding the page may be busy, or off-line. Try again later, trying to avoid the peak times for that server, especially busy US sites.
Some servers do go off-line at night. Try again at a different time, after a week day.
It's very slow fetching pages
There are several reasons why pages fetch slowly. Some solutions are:
Fresco didn't fetch all the graphics
Sometimes part of a file, such as a graphics file, may fail to load, or load incorrectly. To solve this, click the Reload button. The page will be fetched again from the Server (not reloaded from the cache).
What does the error message `No data could be fetched for this URL' mean?
Any of the following:
Test your connection by trying other sites.
Some pictures do not display properly or are only partially displayed.
When trying to access a URL, I get the message `404 File not found'.
The server exists but the file which you requested is not valid. This could be because the file was moved somewhere else, was removed or that you entered the URL incorrectly.
When trying to access a URL, I get a message saying that this page can only be viewed with Netscape x.xx or higher.
The author of the web page(s) assumes that only Netscape can be used to view these pages. There is nothing you can do about this other than to complain to the site's web master. As more web browsers are made available this is likely to occur less and less. The faking facilities available as part of the ANTUtils may resolve these type of problems.
Pictures are not saved when I save a page as HTML.
An HTML document only contains links to images rather than the images themselves. The images are always separate files which are stored on the server. Saving the page as a Draw file will save both text and images as a single file: see 7.5 Exporting information from Fresco.
`Transport for this URL is not supported'. What does this mean?
Fresco can handle various types of transport such as http://, ftp://, gopher:// etc.. If an attempt is made to visit a URL which has a transport type that is not supported by Fresco, this error will be generated e.g. https:// which is the secure http protocol.
How can I prevent children from accessing unsuitable sites?
Fresco lets you restrict the Web sites that can be accessed. See section 7.4, Controlling access to sites.
`The access control list denies access to the requested site.' What does this mean?
See section 7.4, Controlling access to sites.
How do I reset my configuration?
If your configuration options become corrupted or damaged or you simply want to return to the defaults, delete the file !Fresco.Config. Next time you run Fresco a new file will be created if you choose Save from the Choices dialogue box.
Some pages look different when viewed with other Web browsers.
A lot of the HTML specification is left open to interpretation by web browser authors, this usually accounts for slightly different appearances of web pages when viewed with different browsers.
In some cases, the HTML itself may be badly written but happens to look okay on the browser used by the page author.
When I try to download a file from a Web site, the page is filled with garbage and no save window appears when the transfer is complete.
This happens because the server is not telling Fresco that the file is a binary/archive and not a HTML page. Try clicking once on the Reload button.
If Fresco thinks that it is an HTML page, it will try to display it. The file can still be saved in the normal fashion by clicking on the disc icon but you must ensure that you set the filetype correctly when it is saved. In most cases, this will be an Archive file.
Sometimes when I download a file from a web site, the Save window appears but the disappears. Does this mean that I have to start the download again?
If this happens, simply click on the link again, the file will be held on disc and will not need to be transferred from the server again.
When I click on a link to a movie, sound file or PDF, Fresco opens a save window. Why is this?
Fresco cannot deal directly with these files. Instead, you must save the file to disc and then give it to an appropriate application.