HTML Viewer is a simple hypertext viewer, or "browser", meant to be used by people who do not have access to a full-featured browser like Mosaic or Netscape. It is also handy for authoring HTML documents, as it does not have the overhead that the more capable browsers have.
The basic code for HTML Viewer was written as a weekend project, and then enhanced over a few weeks. The reason that the viewer could be written so quickly is due in large part to the existence of Marco Piovanelli's WASTE text engine, for which I am greatful. This library made it possible to overcome the limitations of the Mac's built-in Text Edit Manager, and also made inline graphics possible.
HTML Viewer implements those portions of HTML that are most widely used. Anything HTML Viewer cannot do is probably something that the average HTML author will not want to do anyway. More details on the limitations of HTML Viewer are given below.
HTML Viewer also implements some simple extensions to HTML (which should be ignored by other browsers) that make it more suitable for distributing on-line documentation. More details on the extensions of HTML Viewer are given below.
"You are about to use one of the most powerful, yet easy to use software programs ever written." I've actually seen this statement on another software package (which will remain nameless). Well, HTML Viewer is not that powerful, but it is pretty easy to use. Just drag and drop any text document onto the HTML Viewer icon. If the text document contains any HTML tags, they will be interpreted (within the stated limitations). If the document is plain text, that's how it will appear. You can also use the Open command from the file menu to open any text document.
If you launch HTML Viewer without a document, a "Home Page" will be displayed (the term "Home Page" comes from the World Wide Web, which uses HTML documents heavily). The Home Page text is read from one of two places, scanned in this order:
If neither of these locations contains any text, then a blank window is displayed. An HTML document can then be opened using drag and drop or the Open command.
HTML Viewer maintains two lists of documents. Documents in these lists can be opened at any time by choosing from the appropriate menu.
This list contains the twenty most recent documents that have been opened. It is maintained by HTML Viewer (i.e., you cannot change the contents except by opening a new document). This list is persistant over multiple launches of HTML Viewer.
This is HTML Viewer's user-configurable document list. Bookmarks can be added to this list in one of two ways. First, you can select some text in a document and then choose the "Add Bookmark" command. You will be prompted for a bookmark label, which will appear in the Bookmarks menu. You can also add any hypertext link to the Bookmarks list by holding down the command key and clicking the link. Note that in this case the link will not be followed.
To remove a bookmark from the Bookmarks list, hold down the command key while selecting the item from the Bookmarks menu.
Some documents will provide an Index to their contents. In such cases, the Index menu appears, and when an item is chosen from it, HTML Viewer will scroll to the proper location in the document. This feature is provided by a simple extension to HTML, and will not be available in other browsers.
HTML Viewer has a few "hidden" features that might prove useful to some people.
Besides these, HTML Viewer also supports Macintosh Drag and Drop from its windows. This is really a feature of WASTE. I've extended this functionality so that GIF images can be dragged to other programs that support Drag and Drop, and will be translated to standard Mac PICTs. This means you can also make "clipping" files of any image if you are running a proper version of Finder.
HTML (HyperText Markup Language) is a powerful publishing tool that can be used to create technical and non-technical documents in a variety of fields. However, like any complex language, only a small subset of the language, a "working vocabulary", will be used by most people. This is especially true for those who use HTML to create World Wide Web pages.
HTML Viewer attempts to understand the most common working vocabulary of HTML, and no more. The three most important features of HTML that are not understood by HTML Viewer are the FIG, MATH, and TABLE related tags. Also missing are many of the attributes that can be added to certain anchors.
HTML Viewer does not currently support forms, either, as there is no way to send forms to the proper destination (HTML Viewer will never handle network connections to Web servers, or FTP, Gopher, etc). However, since it is nice to be able to see what a form will look like when designing it, HTML Viewer will support forms in a later version.
Most attributes are not supported. The exceptions to this rule are the HREF, NAME, SRC, and ALIGN attributes, which are necessary in order to locate and navigate files (well, the ALIGN attribute is just for looks). The HREF and NAME attribute are only recognized in the <A...> anchor (as is the ISIX extension attribute). The SRC and ALIGN attributes are only recognized in the <IMG...> anchor.
Finally, HTML Viewer will currently only handle one attribute per anchor. This means that you cannot do something like this:
...<A HREF=foo NAME=bar> Foobar <\A>...
You can easily get around this limitation by using the following construct:
...<A HREF=foo> <A NAME=bar> Foobar <\A> <\A>...
HTML Viewer is forgiving of missing <P> and/or </P> tags, although the rules for whitespace will not be overridden. This is about the extent of HTML Viewer's flexibility. If you are creating an HTML document, you should make every effort to write "good" HTML. Using HTML Viewer to check the layout of your work will be a good test whether or not you have succeeded. I still don't know if this is a feature or a flaw, but it is staying the way it is. Think of HTML Viewer as the lint of HTML ;-)
If you come across any other glaring omissions or strange behaviour in HTML Viewer, please let me know.
Extensions are typically only interesting to HTML authors, as they are not available except through the use of HTML. There are many good reasons why HTML browsers should not define any extensions and instead rely on the standard HTML as currently defined. There are even more reasons why HTML authors should not use any browser-specific extensions, but the main one is that the person who reads the document might not be using that particular browser.
None-the-less, I have decided to include two simple extensions in HTML Viewer so that it would be more useful for distributing on-line documentation. Both of these extensions will be ignored by other browsers.
The more useful extension is the ISIX attribute. When this attribute appears in a name anchor (<A NAME), HTML Viewer will place an item in the Index menu. For example:
...<A NAME = "Licensing" ISIX> Licensing Restrictions <\A>...
This anchor places an item named "Licensing" in the Index menu. When the user chooses that item, HTML Viewer will scroll to and select the enclosed text (in this case, "Licensing Restrictions"). Note that the value of the NAME attribute is used for the menu item.
There might be a better (or official) way to do this in HTML. If you know this for sure, let me know and I'll do it right. This is the second method that I've used for the index extension. The first method is still supported, but had some side effects that this new method does not have.
The second extension is most useful when writing HTML documents. If you have a graphic in PICT format and don't want to take the time (yet) to convert it to GIF format, then you can still view it in HTML Viewer. To do so, you must rename the file with the ".pict" extension, as HTML Viewer determines the type of a graphic file using its extension. You then use the standard method for including an inline image:
...<IMG SRC = "my_graphic.pict">...
Since other browsers do not support PICT files, you should convert any of these images to GIF format before distributing your HTML document.
Send e-mail on the Internet to kurash@dartmouth.edu, or on AppleLink to SASSAFRAS. You can send postal mail to:
Sassafras SoftwareBecause HTML Viewer uses the WASTE engine and reads GIF files, and also because it's just plain useful, there is no charge for non-commercial use. This means that you can use HTML Viewer without paying us anything, but if you want to charge for it you will have to get proper licenses from us (Sassafras Software), Marco Piovanelli (for WASTE), and CompuServe (for GIF).
Copyright. HTML Viewer (the "Software") and any accompanying documentation or written materials (the "Documentation") is copyrighted. You may make copies of the Software and Documentation, provided that you include the Sassafras copyright notice on all copies. Other duplication of the Software or the Documentation is strictly prohibited under the United States copyright laws and international treaties.
Limited warranty and disclaimer of liability. Sassafras makes no warranties, either express or implied, with respect to the Software or included written materials, its quality, performance, merchantability, or fitness for any particular purpose. The Software and written materials are provided "as is" without warranty of any kind. We cannot guarantee you uninterrupted service or the correction of any errors. The entire risk as to the results and performance of the Software is assumed by you. In no event will Sassafras, or anyone else who has been involved with the creation, production or delivery of this product, be liable for direct, indirect, incidental, or consequential damages arising out of the use of, or inability to use the product even if Sassafras has been advised of the possibility of such damages. Because some states do not allow the exclusion or limitation of liability for consequential or incidental damages, the above limitation may not apply to you. Our liability for any damage to you or any party in the event that any of the above limitations are held unenforceable shall not exceed the license fee you paid, regardless of the form of any claim.
Sassafras and the Sassafras logo are registered trademarks of Sassafras Software Inc.
HTML Viewer © 1995 Sassafras Software Inc.
WASTE text engine © 1993-1995 Marco Piovanelli
The Graphics Interchange Format © is the Copyright property of CompuServe Incorporated. GIF(sm) is a Service Mark property of CompuServe Incorporated.
All other product or brand names mentioned in this documentation are trademarks or registered trademarks of their respective companies.