[brailleblaster] Another version of the block diagram
- From: "John J. Boyer" <john.boyer@xxxxxxxxxxxxxxxxx>
- To: brailleblaster@xxxxxxxxxxxxx
- Date: Mon, 15 Oct 2012 22:57:28 -0500
Some things have been clarified. Steps have been slightly rearranged.
Notes on user setings and a sample semantic-action file have been
included.
--------------------
This is a sort of informal block diagram in narrative form. It is
intended as a guide for the future development of BrailleBlaster.
Input may be in the form of an xml file or it may be a utd working file
which has been saved so that work can be resumed later. xml files may be
original well-formed files of any flavor, for example, dtbook, docbook,
etc. They may also be derived from other formats such as MSWord, rtf,
and so on. Another source is file sets, such as NIMAS or epub. In this
case the manifest is opened, and the file to be processed is chosen from
it. A means is provided to concatenate several files into one. xml files
can also be derived from plain-text by calling the translateTextFile
method with formatFor utd or from brf files by calling backTrnslateFile,
also with formatFor utd.
Whatever its source, an xml file is rendered by calling translateFile
with formatFor utd. BrailleBlaster then works on the utd file produced.
In the case of formerly saved utd files or those produced by importing
plain text or brf files, BrailleBlaster works with these directly.
Configuration files have been eliminated in this revision because most
of the information they would contain belongs in the UserSettings file
or in the semantic-action file for the particular xml flavor. Some of
the things which may be specified in the UserSettings file are listed
in Appendix A.
Semantic-action files are then read. A file is chosen by looking for a
file with the name of the root element and the extension .sem It is used
to construct the semantic table, which will be used for determining how
information should be displayed on the screen and what markup should be
used when new information is added. For more on semantic-action files
see Appendix B. Appendix C. gives an example semantic-action file.
The input file is then parsed to produce a parse tree.
If the semantic-action files contain XPath expressions as keys these are
applied to the parse tree, and the selected nodes are modified by adding
an attribute indicating the entry in the semantic table to be used. The
value of each key will already have been entered into this table.
The keys containing markup in the semantic files are then applied to the
parse tree, and a similar attribute is added to the matching nodes,
unnless it is already present because it has been added by an XPath
expression.
This forms the DOM of the document.
This DOM is then used to display the document on the screen. Both the
print and Braille windows are filled in this process. The print window
resembles WordPad. The Braille window shows the Braille line-by-line,
with blank lines, indentations, etc. Its editor is like a simple text
editor, but with features for locking Braille.
Editing of the print document can then take place. If the contents of a
text node are altered the new contents replace the old. They are also
dynamically translated and the translation is shown in the Braille
window. If an element node is deleted its entire subtree is deleted. If
a new block of characters is created the user is prompted to asign it a
style and a node with the appropriate markup (derived from the
semantic-action files) is added to the document at the place where the
new block was created.
if focus is shifted to the Braille window and the user has checked the
Edit Braille box on the advanced menu the window can be edited. Any
editing is highlighted in both the Braille and print windows. The print
window also changes to show the part of the original text that
corresponds to each line of Braille.
Since the user may wish to view the result of editing Braille in the
context of the entire document, The translate and back-translate items
on the menu are replaced with retranslate and reback-translate.
The file can be saved as a utd file so work can be resumed later or it
can be saved as the original xml file with enhancements. These consist
of edited Braille which has been moved into the print document with
proper markup (specified in the semantic-action files). The attributes
used to create the DOM are removed during the save process. Editing in
the print window is handled automatically as part of the conversion of
the parse tree to a file.
Besides saving the file as utd or as an enhanced document, it can be
saved as a brf file or embossed.
The enhanced document can then later be rendered by liblouisutdml with
any liblouisutdml configuration and semantic-action files that the user
wishes. This can be done either by BrailleBlaster or by another
application which uses the loblouis-liblouisutdml transcription engine.
Appendix A. User settings
The settings below are largely for printed output. Analogous settings
for embosser output would be included.
hyphenate=no
topMargin=0.5
leftMargin=1
rightMargin=0.5
bottomMargin=0.5
paperHeight=11
paperWidth=8.5
Appendix B: Semantic-Action Files
Semantic-action files associate the markup in a particular type of xml
document with BrailleBlaster styles, methods (actions) and macros.
Usually they are named by concatenating the name of the root element of
the document flavor with the extension .sem They are not to be confused
with liblouisutdml semantic-action files. The latter are concerned with
rendering an xml document into Braille and tactile graphics.
BrailleBlaster semantic-action files are concerned with displaying the
contents of a document on the screen and with editing them. Their format
is completely different from the format of liblouisutdml semantic-action
files. They are stored in the semantics directory in the programData
directory. There is a dialogue for creating and editing them. If an
unknown xml flavor is encountered a prototype semantic-action file is
created.
the key part of a line in a semantic-action file is a reference to
markup in the document. This may be literal markup or an XPath
expression. There are a few exceptions, which will be discussed later.
The value part contains the name of a style or action, or of a macro,
which can combine several styles and actions. it may also contain
parameters.
Literal keys may have one of the following forms: an element name; an
element name, a comma, and an attribute name; an element name, a comma,
an attribute name, an attribute value. XPath keys begin with the
characters &xpath with the XPath expression imediately following and
enclosed in parentheses. The key may also be the word newEntries. If the
value is yes markup which has not yet been associated with anything is
recorded and placed in a prototype semantic-action file. The key may
also be the word file, followed by a colon followed by a filename. In
this case the value is the word include, and the line specifies that
another semantic file should be read at this point. Finally, the key may
be internetAccessRequired This is used to specify that internnet access
is needed to process this xml flavor.
Values start with one of the words action macro style. This is followed
by a space. If action is specified, the action is one of those below. If
style is specified a style name follows. The extension .properties is
added to it and it is looked up in the styles directory. Likewise,
macros are looked up in the macro directory. All three may have
parameters preceded by a space and separated by comas.
The following actions may be specified.
internetAccessRequired, This document needs Internet access.
no, Do nothing except insert a space.
skip, Skip the subtree of which this markup is the root.
generic, Apply the parameters.
cdata, Special processing for CData sections.
htmllink, Insert a link
htmltarget, to this target.
# reserved styles. These styles are predefined, but may be altered
document, Assign to the node that actually contains the content, such
as the book node in dtbook.
para, A paragraph.
heading1,various levels of headings
heading2,
heading3,
heading4,
heading5,
heading6,
heading7,
heading8,
heading9,
heading10,
contentsheader, The heading of the table of contents.
contents1, Various levels within the contents.
contents2,
contents3,
contents4,
contents5,
contents6,
contents7,
contents8,
contents9,
contents10,
# General text
notranslate, do not translate the contents of the markup.
attrtotext, Transform an attribute value to text.
runninghead, Specify a running header.
footer, Specify a page footer.
boxline, Specify a line of identical characters.
italic, Italicise the text within the markup.
bold, Bold it.
underline, Underline it.
compbrl, Show it in computer Braille.
linespacing, Number of blank lines between lines of characters.
blankline, Leave a blank line.
softreturn, Start a new line, but not a new style.
newpage, Start a new page.
brl, Process the <brl> subtree rooted at this node.
music, Display/edit the music notation in this subtree.
math, Display/edit the MathML notation in this subtree.
chemistry, Display/edit the chemistry notation in this subtree.
graphic, Display/edit the graphic pointed to by the markup.
Appendix C. Example Semantic-Action File (dtbook.sem)
newEntries=no
internetAccesRequired=no
book=style document
docauthor=style para
p=style para
doctitle=style heading1
h1=style heading1
h2=style heading2
h3=style heading3
h4=style heading4
h5=style heading4
h6=style heading4
a,href=action htmlLink
a,name=action htmlTarget
code=style computerCode
code,class,inline=action compbrl
span,class,italic=action italic \s,\s
b=action bold
acronym=action notranslate
li=style list
pagenum=action pagenum
th=style para
tr=style para
strong=action italic \s,\s
code,class,display=style computerCode
em=action italic \s,\s
note=style note
blockquote=style blockquote
samp=style para
sidebar=style para
br=action softReturn
abbr=style para
--
John J. Boyer; President, Chief Software Developer
Abilitiessoft, Inc.
http://www.abilitiessoft.com
Madison, Wisconsin USA
Developing software for people with disabilities
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