News For Previous Grail Releases

New Features in Grail 0.3

Many bugs present in previous versions have been fixed. (See also the list of Grail 0.2 bugs fixed.)

Contents:

• New in Grail 0.3 (final)
• New in Grail 0.3b3
• New in Grail 0.3b2
• General
• HTML
• User Interface
• Printing
• Applets
• Advanced HTML
• SGML

New in Grail 0.3 (final)

• All showstopper bugs in 0.3b3 fixed.
• New -d/--display option.
• More (XXX To be done).

New in Grail 0.3b3

General:
• Support optional use of the Python Imaging Library if available and Tk integration is detected. This allows support of most image formats used on the Web without requiring NetPBM or other external filters. This allows better handling than Tk for some GIF images and supports JPEG/JFIF and PNG images directly, including transparent PNGs and image scaling. Add the line:

  	browser--enable-pil: 0

  to the ~/.grail/grail-preferences file if you don't want to use PIL for some reason. Leaving it enabled will not affect Grail if PIL is not available.
• Support standardized color names from the HTML 3.2 (``Wilbur'') W3C recommendation.
• Revise interpretation of " " to be more like that of other browsers by default. The more correct interpretation is used when ``advanced'' recognition mode is enabled.
• Implemented client-pull updating of documents.
• Fixed a bunch of really tedious bugs.
• Use filetypes extension mechanism to load the parsers for text/html and text/plain; this allows user customization of the existing parsers via subclassing as well as replacement.
• Support ALIGN, BGCOLOR, and VALIGN attributes for table cells.

User Interface:
• Added a ``Document Info'' window showing server response headers and query fields. Also indicates whether or not the document was loaded from the cache.
• Added command to open the URL marked by the selection.
• Extended the document menu (third button for X11 users) to allow access to the Document Info window for a frame, open or save an image under the pointer, and bookmark, print, or save the document pointed to by a link under the pointer.
• Allow the bookmarks file title to be edited similarly to bookmark section headers.
• History dialog key bindings more closely match those of the Bookmarks dialog.
• Downloads are now fully asynchronous.
• Grail-initiated ``Save As...'' dialogs now indicate the content type of the document being saved.

Applets:
• Applet objects may now provide an additional special method, __cleanup__(), that is called when the viewer is reset in preparation for loading another page. This allows applets to release resources if needed.

Printing:
• Paper size and orientation may be configured in the ``Printing Preferences'' dialog. Additional configurability for printing is supported.
• Base font size and leading distance are now configurable.
• Local files may be printed even if a MIME type cannot be determined; the type text/plain is used and the user is warned.
• Horizontal alignment is now supported.
• Improved wrapping of text at the right margin.
• Right-hand margin now supported for BLOCKQUOTE element.
• Added support for BIG and SMALL elements, also <FONT SIZE="..."> elements (other FONT attributes are ignored).

New in Grail 0.3b2

• Dan Connolly's SGML lexer code has been removed temporarily, until we have more clarity about its copyright status.
• Interpretation of sys.argv[0] is even more clever now -- it follows symbolic links, so you can have a symlink "/usr/local/bin/grail" pointing to the grail.py file where it is installed.
• Fixed problem retrieving ftp: URLs containing %-quoted characters in the filename.
• Tables: bug fixes and memory leaks patched; some minor performance improvements.
• Coloring of active link (red) takes place at the right time.
• Histification (i.e. adding to the global history list and coloring the link purple) of link when saving a file (via FileDialog) has been fixed.
• Bookmarks: Fixes to various dialog windows so that window deletes via the window manager are handled properly. The Insert Entry (`K') command no longer adds bogus leading spaces in Location field. Fixed a bug when popping up main bookmarks dialog after Browser window has been deleted. Allowed bookmarks and history to load pages into new windows.
• Remote control: More robustness in checking the remote control socket. If a socket is found to have a live Grail on the other end, the new Grail will not abscond with it. If the socket doesn't have a live Grail (i.e. doesn't respond to a PING), then the new Grail will steal the socket. Some API changes to allow for callbacks to respond to the remote caller (see the web page). Fixed broken import of tkinter.
• Choose default font sizes that are more generally available (superseding the patch for 0.3b1).
• Generalized the fonts preferences scheme so it includes symbols and dingbats.
• Proxy support enhancement: the proxy exceptions list now supports the use of domain wildcards by specifying a domain with a leading dot (e.g., .python.org).
• HTML parsing and display:
  • Header numbering is enabled automatically only on encountering a SKIP or SEQNUM attribute on a header.
  • Math & Greek entities support resizing when the needed fonts are available (always for Greek). Bullets use Dingbat font when the size needed is available but fallback to constant size GIFs if needed.
  • Improved handling of URLs containing whitespace.
  • Supported <HR SRC="...">.
  • Added some additional font-based entities based on HTML 3.0 and existing practice.
  • Added support for <FN ID="name">, empty <A NAME="name"> and <FN ID="name"> elements.
  • Fixed indentation of nested definition lists.
  • Improved compatibility of comment recognition in non-strict mode; robustification in both modes.
• Printing changes:
  • De-tab PRE data before display; corrects lots of problems in preformatted text.
  • Fixed some vertical spacing problems.
• Context/AsyncImage, bug fixed: make sure that only a single AsyncImage reader is created for an image. Bug occured when a page had multiple inlines of the same image; a seperate reader was created for each one.
• Save to disk: when a user decides to save a file to disk instead of viewing it, boost the readers bufsize to 8k. Makes downloading a little faster.
• IOError, bug fix: catch exceptions from the protocol object in BaseReader. Prevents socket errors from crashing grail.
• SocketQueue: control for the number of sockets open at one time. Involved changes to grail.py (added SocketQueue) and extensive changes to http protocol api and base reader so that they don't open connections immediately, but wait to be called back by socket queue.
• SocketQueue/display: the number of active streams is shown in the status window along with the total number of streams.
• SharedItem/SharedAPI: changed name of CacheItem/API. The old names were confusing because a SharedAPI for a SharedItem is returned by grail.open_url regardless of whether the item is in the cache. The primary purpose of these objects is to allow multiple readers to share the same protocol object.
• Synchronous refresh, bug fix: when a page in the cache needed to be refresh, the HTTP If-Modified-Since request was made synchronously. Ouch! Changed so that SharedItem does this asynchronously.
• SharedItem.getdata, performance fix for reading files: each time getdata was called, the SharedItem stored the results of reading from the protocol object by using string append (e.g. data = data + new). This was expensive, so data became a list of strings and a dictionary of offsets to string indices. This makes performance much faster in the common case where there is a single reader and the data member is used *only* to write to the cache. Performance is also improved for multiple readers, because they probably all ask for the same chunks of data in the same order; as a result, we can just hand them back successive strings from the data list.
• Cache log, performance improvement: the cache log code was also written with string appends (e.g. field1 + field2 + field3 + ... + fieldn). Changed this to a string.join, which improved performance by 70 percent.

General

• An architecture for user preference management has been implemented.
• A proper persistent disk cache replaces the in-memory cache.
• An attempt has been made at improving performance, but there's still a long way to go...

Major HTML Features

• Grail now supports tables (to the extent made possible by Tk).
• Grail now supports frame sets, much like Netscape's. The pop-up menu bound to mouse button 3 supports frame-specific operations.
• Improvements to forms:
  • Form contents is now retained in history stack.
  • Input items with type=image.
  • File upload.
• More image formats (JPEG, XBM, TIFF) are supported if NetPBM is present.

User Interface

• A preferences menu with dialogs to control aspects of Grail's behavior is now provided.
• I/O status messages now show the percentage or number of bytes received.
• An I/O status monitor window has been added for more detailed viewing of I/O status.
• The file selector boxes for Save As and Open File are much improved: they remember their last directory, contain scroll bars, and support ~ expansion.
• History commands (Back, Reload, Forward) and "Clone current window" remember the scrolling position as well as forms contents.
• The bookmarks viewer interface has been reorganized.
• The Bookmarks and History dialogs support loading a selection into a new browser window using a double-click on mouse button 2. The Bookmarks dialog also provides this in the menus.
• Several dialogs (e.g. Find, and perhaps most importantly the splash screen) no longer need to be placed manually.
• All windows and dialogs now support Alt-W as a shortcut for Close or Cancel, as well as the window manager "delete window" operation.
• Mouse button 3 is now bound to a pop-up menu with some common operations. The "open this link in a new window" command has been moved to mouse button 2.
• A "smooth scrolling hack" can optionally be installed. This allows viewing of images or tables larger than the screen. Its use is a mixed blessing, unfortunately; the Page Down/Up keyboard shortcuts and Tk's middle-mouse-button scrolling feature don't work any more, applets that resize their frame may end up partially hidden, scrolling to a fragment identified by <A NAME="id">...</A> doesn't work, and (worst of all) scrolling big tables looks horrible. We really need to put more pressure on Ousterhout's group to add smooth scrolling to the text widget.

Printing

• Faster!
• Now handles images, including the ALIGN attribute, if NetPBM is present.
• Output includes footnotes for anchors found in the document, page header with the document title, and a page footer with the document URL and page number. Footnotes and anchor underlines are optional, and can be toggled from the Print dialog. Footnotes make use of the advisory TITLE attribute of the <A> tag if present.
• Added support for arbitrary nesting of <SUP> and <SUB> elements. <SUB> and <SUP> are currently only supported in printing.
• Some printing features can be controlled by check buttons in the print dialog.
• Text containing tabs in <PRE> elements is now printed correctly.

Applets

• Two new tags are supported to embed applets in a page: <OBJECT> (a W3C proposal) and <APPLET> (also used by Java).
• It is possible to disable applet loading selectively or completely.
• Applets have much more restricted access to Grail objects, and all objects are now "bastionized", meaning that their instance variables are made unaccessible and only selected methods can be called.
• Applets are now divided in "applet groups" based on the host or domain name of the server from which the HTML page containing the applet is loaded. Each group has its own restricted execution environment, so applets can't mess with each other's globals.
• Applets can now write files in an area reserved to their applet group (and only there).

Advanced HTML

Many of the features added are defined in some form in the expired HTML 3.0 internet draft. While we recognize that the draft is no longer considered a significant document and is not on a standards track, it has proved a valuable source of direction for many extensions to HTML 2.0. Hence, it has been used as an advisory document during the development of Grail's HTML support. A detailed description of Grail's HTML support is available.

• Headings (<H1> .. <H6>) now support the ALIGN, DINGBAT, and SRC attributes proposed in HTML 3. For ALIGN, the 'justify' alternative is not supported: the value of ALIGN must be left, center, or right.
• Footnotes (<FN ID=name>) are supported as link targets.
• Strike-out is supported by the <S> and <STRIKE> elements. Note the <S> is font-oriented markup and <STRIKE> is logical markup. <S> is proposed in HTML 3.0, and <STRIKE> is implemented by some other browsers. Logical markup also makes more sense. The <DEL> element should probably be preferred to <STRIKE> since it is part of the formal HTML 3.0 proposal.
• Underlining is supported by the <U> element. This is from the HTML 3.0 proposal.
• Inserted and deleted text are supported via the <INS> and <DEL> elements. These are derived from the HTML 3.0 proposal.
• <BLOCKQUOTE> provides a right margin.
• Target anchors (<A NAME=id></A>) and footnotes (<FN ID=id></FN>) with no content are correctly supported.
• Iconic entities as proposed in a W3C working draft. The mechanism used to implement this is extensible & customizable.
• <HR> elements now handle the ALIGN, NOSHADE, SIZE, SRC, and WIDTH attributes. For printing, NOSHADE is always assumed.
• Several improvements in lists have been made:
  • <OL> supports the START and SEQNUM attributes.
  • <LI> tags now handle the DINGBAT, SEQNUM, and VALUE attributes, and emulates other browsers' ideas about TYPE more flexibly. Real bullets are provided (disc, circle, and square).
  • The <LH> (list heading) tag from HTML 3 is dealt with intelligently, and is affected by the COMPACT attribute of the enclosing list.
  • The COMPACT attribute is propogated to nested lists.
  • Formatting is generally more reasonable, and nested block elements are correctly sized and indented.
• <ISINDEX> now understands the HREF attribute defined in HTML 3.
• Support for the ALIGN attribute on DIV and P elements is provided. The 'justify' option, however, is not: the value of ALIGN must be left, center, or right.
• Content of the <SCRIPT> and <STYLE> elements is discarded rather than displayed.
• Closure of open elements is handled more intelligently as the document is parsed.

SGML

There have been many mprovements in the SGML capabilities underlying the HTML support. These affect the HTML handling provided with Grail and any extensions built on the SGML layer. These changes are mostly of interest to extension authors.

• Grail ensures that open contained elements are closed in the correct order even if some end tags are ommitted. An example of this in HTML would be: <P>text..<A NAME=target>more text</P>. In this instance, the handler for the end tag of the A element would be called before the end tag handler for the P element. Many HTML browsers get this wrong.
• Provided a preference setting to allow stricter parsing of SGML syntax. Enabling ``advanced'' SGML recognition enables support for named character entities, null end tags, empty tags, and unclosed tags. Note that these are not normally recognized by other browsers; the default is ``browser style'' parsing. The parsers for each DTD must explicitly select the parsing modes.
• Entity references in attribute values are now handled properly. Iconic entities are not supported in attribute values.
• Changed approach to passing attributes to start-tag handlers. Extensions for individual tags are backward compatible, but methods of parser classes based on SGMLParser are not. New modules are provided for the new SGML base implementation; these are required for extensions wishing to support the faster lexical analyzer or to track future improvements in the SGML base.

The list of features new in Grail 0.2 is still available.