/**
* Returns a string built using a particular grammar. Single-quotes strings are counted as literal
* strings, whereas all other strings appearing in the grammar require substitution with the
* corresponding value from the extraparams hashmap.
*/
private String buildGrammar(String grammar, Map<String, String> extraparams) {
StringBuilder outboundstring = new StringBuilder();
String[] fields = Pattern.compile("\\s+").split(grammar);
for (int i = 0; i < fields.length; i++) {
if (fields[i].substring(0, 1).equals("'")) {
outboundstring.append(fields[i].substring(1, fields[i].length() - 1));
} else {
outboundstring.append(extraparams.get(fields[i]));
}
}
return outboundstring.toString();
}
/**
* Returns the value of a specified fieldname from the specified hashmap and returns an integer
* value or throws an exception if the value is not an integer
*/
private int getIntValue(String fieldname, Map<String, String> extraparams) {
Matcher checkint = Pattern.compile("^\\d+$").matcher(fieldname);
int rv;
if (checkint.matches()) {
rv = Integer.parseInt(fieldname);
} else {
if (extraparams.containsKey(fieldname)) {
rv = Integer.parseInt(extraparams.get(fieldname));
} else {
rv = -1;
throw new TDTException(
"No integer value for " + fieldname + " can be found - check extraparams");
}
}
return rv;
}
/**
* Adds additional entries to the extraparams hashmap by processing various rules defined in the
* TDT definition files. Typically used for string processing functions, lookup in tables,
* calculation of check digits etc.
*/
private void processRules(Map<String, String> extraparams, Rule tdtrule) {
String tdtfunction = tdtrule.getFunction();
int openbracket = tdtfunction.indexOf("(");
assert openbracket != -1;
String params = tdtfunction.substring(openbracket + 1, tdtfunction.length() - 1);
String rulename = tdtfunction.substring(0, openbracket);
String[] parameter = params.split(",");
String newfieldname = tdtrule.getNewFieldName();
// System.out.println(tdtfunction + " " + parameter[0] + " " + extraparams.get(parameter[0]));
/**
* Stores in the hashmap extraparams the value obtained from a lookup in a specified XML table.
*
* <p>The first parameter is the given value already known. This is denoted as $1 in the
* corresponding XPath expression
*
* <p>The second parameter is the string filename of the table which must be present in the
* auxiliary subdirectory
*
* <p>The third parameter is the column in which the supplied input value should be sought
*
* <p>The fourth parameter is the column whose value should be read for the corresponding row,
* in order to obtain the result of the lookup.
*
* <p>The rule in the definition file may contain an XPath expression and a URL where the table
* may be obtained.
*/
if (rulename.equals("TABLELOOKUP")) {
// parameter[0] is given value
// parameter[1] is table
// parameter[2] is input column supplied
// parameter[3] is output column required
assert parameter.length == 4 : "incorrect number of parameters to tablelookup " + params;
if (parameter[1].equals("tdt64bitcpi")) {
String s = extraparams.get(parameter[0]);
assert s != null : tdtfunction + " when " + parameter[0] + " is null";
String t = gs1cpi.get(s);
assert t != null : "gs1cpi[" + s + "] is null";
assert newfieldname != null;
extraparams.put(newfieldname, t);
// extraparams.put(newfieldname, gs1cpi.get(extraparams.get(parameter[0])));
} else { // JPB! the following is untested
String tdtxpath = tdtrule.getTableXPath();
String tdttableurl = tdtrule.getTableURL();
String tdtxpathsub = tdtxpath.replaceAll("\\$1", extraparams.get(parameter[0]));
extraparams.put(newfieldname, xpathlookup("ManagerTranslation.xml", tdtxpathsub));
}
}
/**
* Stores the length of the specified string under the new fieldname specified by the
* corresponding rule of the definition file.
*/
if (rulename.equals("LENGTH")) {
assert extraparams.get(parameter[0]) != null
: tdtfunction + " when " + parameter[0] + " is null";
if (extraparams.get(parameter[0]) != null) {
extraparams.put(newfieldname, Integer.toString(extraparams.get(parameter[0]).length()));
}
}
/**
* Stores a GS1 check digit in the extraparams hashmap, keyed under the new fieldname specified
* by the corresponding rule of the definition file.
*/
if (rulename.equals("GS1CHECKSUM")) {
assert extraparams.get(parameter[0]) != null
: tdtfunction + " when " + parameter[0] + " is null";
if (extraparams.get(parameter[0]) != null) {
extraparams.put(newfieldname, gs1checksum(extraparams.get(parameter[0])));
}
}
/**
* Obtains a substring of the string provided as the first parameter. If only a single second
* parameter is specified, then this is considered as the start index and all characters from
* the start index onwards are stored in the extraparams hashmap under the key named
* 'newfieldname' in the corresponding rule of the definition file. If a second and third
* parameter are specified, then the second parameter is the start index and the third is the
* length of characters required. A substring consisting characters from the start index up to
* the required length of characters is stored in the extraparams hashmap, keyed under the new
* fieldname specified by the corresponding rule of the defintion file.
*/
if (rulename.equals("SUBSTR")) {
assert extraparams.get(parameter[0]) != null
: tdtfunction + " when " + parameter[0] + " is null";
if (parameter.length == 2) {
if (extraparams.get(parameter[0]) != null) {
int start = getIntValue(parameter[1], extraparams);
if (start >= 0) {
extraparams.put(newfieldname, extraparams.get(parameter[0]).substring(start));
}
}
}
if (parameter.length
== 3) { // need to check that this variation is correct - c.f. Perl substr
assert extraparams.get(parameter[0]) != null
: tdtfunction + " when " + parameter[0] + " is null";
if (extraparams.get(parameter[0]) != null) {
int start = getIntValue(parameter[1], extraparams);
int end = getIntValue(parameter[2], extraparams);
if ((start >= 0) && (end >= 0)) {
extraparams.put(
newfieldname, extraparams.get(parameter[0]).substring(start, start + end));
}
}
}
}
/**
* Concatenates specified string parameters together. Literal values must be enclosed within
* single or double quotes or consist of unquoted digits. Other unquoted strings are considered
* as fieldnames and the corresponding value from the extraparams hashmap are inserted. The
* result of the concatenation (and substitution) of the strings is stored as a new entry in the
* extraparams hashmap, keyed under the new fieldname specified by the rule.
*/
if (rulename.equals("CONCAT")) {
StringBuilder buffer = new StringBuilder();
for (int p1 = 0; p1 < parameter.length; p1++) {
Matcher matcher = Pattern.compile("\"(.*?)\"|'(.*?)'|[0-9]").matcher(parameter[p1]);
if (matcher.matches()) {
buffer.append(parameter[p1]);
} else {
assert extraparams.get(parameter[p1]) != null
: tdtfunction + " when " + parameter[p1] + " is null";
if (extraparams.get(parameter[p1]) != null) {
buffer.append(extraparams.get(parameter[p1]));
}
}
}
extraparams.put(newfieldname, buffer.toString());
}
}
/** convert from a particular scheme / level */
private String convertLevel(
Scheme tdtscheme,
Level tdtlevel,
String input,
Map<String, String> inputParameters,
LevelTypeList outboundlevel) {
String outboundstring;
Map<String, String> extraparams =
// new NoisyMap
(new HashMap<String, String>(inputParameters));
// get the scheme's option key, which is the name of a
// parameter whose value is matched to the option key of the
// level.
String optionkey = tdtscheme.getOptionKey();
String optionValue = extraparams.get(optionkey);
// the name of a parameter which allows the appropriate option
// to be selected
// now consider the various options within the scheme and
// level for each option element inside the level, check
// whether the pattern attribute matches as a regular
// expression
String matchingOptionKey = null;
Option matchingOption = null;
Matcher prefixMatcher = null;
for (Enumeration e = tdtlevel.enumerateOption(); e.hasMoreElements(); ) {
Option opt = (Option) e.nextElement();
if (optionValue == null || optionValue.equals(opt.getOptionKey())) {
// possible match
Matcher matcher = Pattern.compile(opt.getPattern()).matcher(input);
if (matcher.matches()) {
if (prefixMatcher != null) throw new TDTException("Multiple patterns matched");
prefixMatcher = matcher;
matchingOptionKey = opt.getOptionKey();
matchingOption = opt;
}
}
}
if (prefixMatcher == null) throw new TDTException("No patterns matched");
optionValue = matchingOptionKey;
for (Enumeration e = matchingOption.enumerateField(); e.hasMoreElements(); ) {
Field field = (Field) e.nextElement();
int seq = field.getSeq();
String strfieldname = field.getName();
int fieldlength = field.getLength();
String strfieldvalue = prefixMatcher.group(seq);
// System.out.println(" processing field " + strfieldname + " = '" + strfieldvalue + "'");
if (field.getCompaction() == null) {
// if compaction is null, treat field as an integer
if (field.getCharacterSet() != null) { // if the character set is specified
Matcher charsetmatcher =
Pattern.compile("^" + field.getCharacterSet() + "$").matcher(strfieldvalue);
if (!charsetmatcher.matches()) {
throw new TDTException(
"field "
+ strfieldname
+ " ("
+ strfieldvalue
+ ") does not conform to the allowed character set ("
+ field.getCharacterSet()
+ ") ");
}
}
BigInteger bigvalue = null;
if (tdtlevel.getType() == LevelTypeList.BINARY) { // if the input was BINARY
bigvalue = new BigInteger(strfieldvalue, 2);
extraparams.put(strfieldname, bigvalue.toString());
} else {
if (field.getDecimalMinimum() != null || field.getDecimalMaximum() != null)
bigvalue = new BigInteger(strfieldvalue);
extraparams.put(strfieldname, strfieldvalue);
}
if (field.getDecimalMinimum() != null) { // if the decimal minimum is specified
BigInteger bigmin = new BigInteger(field.getDecimalMinimum());
if (bigvalue.compareTo(bigmin)
== -1) { // throw an exception if the field value is less than the decimal minimum
throw new TDTException(
"field "
+ strfieldname
+ " ("
+ bigvalue
+ ") is less than DecimalMinimum ("
+ field.getDecimalMinimum()
+ ") allowed");
}
}
if (field.getDecimalMaximum() != null) { // if the decimal maximum is specified
BigInteger bigmax = new BigInteger(field.getDecimalMaximum());
if (bigvalue.compareTo(bigmax)
== 1) { // throw an excpetion if the field value is greater than the decimal maximum
throw new TDTException(
"field "
+ strfieldname
+ " ("
+ bigvalue
+ ") is greater than DecimalMaximum ("
+ field.getDecimalMaximum()
+ ") allowed");
}
}
// after extracting the field, it may be necessary to pad it.
padField(extraparams, field);
} else {
// compaction is specified - interpret binary as a string value using a truncated byte per
// character
CompactionMethodList compaction = field.getCompaction();
PadDirectionList padDir = field.getPadDir();
String padchar = field.getPadChar();
String s;
if (compaction == CompactionMethodList.VALUE_5)
// "5-bit"
s = bin2uppercasefive(strfieldvalue);
else if (compaction == CompactionMethodList.VALUE_4)
// 6-bit
s = bin2alphanumsix(strfieldvalue);
else if (compaction == CompactionMethodList.VALUE_3)
// 7-bit
s = bin2asciiseven(strfieldvalue);
else if (compaction == CompactionMethodList.VALUE_2)
// 8-bit
s = bin2bytestring(strfieldvalue);
else throw new Error("unsupported compaction method " + compaction);
extraparams.put(strfieldname, stripPadChar(s, padDir, padchar));
}
} // for each field;
/**
* the EXTRACT rules are performed after parsing the input, in order to determine additional
* fields that are to be derived from the fields obtained by the pattern match process
*/
int seq = 0;
for (Enumeration e = tdtlevel.enumerateRule(); e.hasMoreElements(); ) {
Rule tdtrule = (Rule) e.nextElement();
if (tdtrule.getType() == ModeList.EXTRACT) {
assert seq < tdtrule.getSeq() : "Rule out of sequence order";
seq = tdtrule.getSeq();
processRules(extraparams, tdtrule);
}
}
/**
* Now we need to consider the corresponding output level and output option. The scheme must
* remain the same, as must the value of optionkey (to select the corresponding option element
* nested within the required outbound level)
*/
Level tdtoutlevel = findLevel(tdtscheme, outboundlevel);
Option tdtoutoption = findOption(tdtoutlevel, optionValue);
/**
* the FORMAT rules are performed before formatting the output, in order to determine additional
* fields that are required for preparation of the outbound format
*/
seq = 0;
for (Enumeration e = tdtoutlevel.enumerateRule(); e.hasMoreElements(); ) {
Rule tdtrule = (Rule) e.nextElement();
if (tdtrule.getType() == ModeList.FORMAT) {
assert seq < tdtrule.getSeq() : "Rule out of sequence order";
seq = tdtrule.getSeq();
processRules(extraparams, tdtrule);
}
}
/**
* Now we need to ensure that all fields required for the outbound grammar are suitably padded
* etc. processPadding takes care of firstly padding the non-binary fields if padChar and
* padDir, length are specified then (if necessary) converting to binary and padding the binary
* representation to the left with zeros if the bit string is has fewer bits than the bitLength
* attribute specifies. N.B. TDTv1.1 will be more specific about bit-level padding rather than
* assuming that it is always to the left with the zero bit.
*/
// System.out.println(" prior to processPadding, " + extraparams);
for (Enumeration e = tdtoutoption.enumerateField(); e.hasMoreElements(); ) {
Field field = (Field) e.nextElement();
// processPadding(extraparams, field, outboundlevel, tdtoutoption);
padField(extraparams, field);
if (outboundlevel == LevelTypeList.BINARY) binaryPadding(extraparams, field);
}
/**
* Construct the output from the specified grammar (in ABNF format) together with the field
* values stored in inputparams
*/
outboundstring = buildGrammar(tdtoutoption.getGrammar(), extraparams);
// System.out.println("final extraparams = " + extraparams);
// System.out.println("returned " + outboundstring);
return outboundstring;
}
@WebService(
endpointInterface = "uk.ac.open.lts.webmaths.image.MathsImagePort",
targetNamespace = "http://ns.open.ac.uk/lts/vle/filter_maths/",
serviceName = "MathsImage",
portName = "MathsImagePort")
public class WebMathsImage extends WebMathsService implements MathsImagePort {
private static boolean SHOWPERFORMANCE = false;
private Graphics2D context;
/** Initialises the graphics context (first time). */
private void initContext() {
if (context == null) {
// Create graphics context used for laying out equation
BufferedImage silly = new BufferedImage(1, 1, BufferedImage.TYPE_INT_ARGB);
context = silly.createGraphics();
}
}
private static final Pattern REGEX_RGB =
Pattern.compile("^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$");
private static final byte[] EMPTY = new byte[0];
@Override
public MathsImageReturn getImage(MathsImageParams params) {
long start = System.currentTimeMillis();
MathsImageReturn result = new MathsImageReturn();
result.setOk(false);
result.setImage(EMPTY);
result.setError("");
try {
// Parse XML
Document mathml = parseMathml(params, result, start);
if (mathml == null) {
return result;
}
return getImage(params, mathml, result, start);
} catch (Throwable t) {
result.setError("MathML unexpected error - " + t.getMessage());
t.printStackTrace();
return result;
}
}
@Override
public MathsEpsReturn getEps(MathsEpsParams params) {
long start = System.currentTimeMillis();
MathsEpsReturn result = new MathsEpsReturn();
result.setOk(false);
result.setEps(EMPTY);
result.setError("");
try {
// Parse XML
Document mathml = parseMathml(params, result, start);
if (mathml == null) {
return result;
}
return getEps(params, mathml, result, start);
} catch (Throwable t) {
result.setError("MathML unexpected error - " + t.getMessage());
t.printStackTrace();
return result;
}
}
/**
* Parses mathml from the input into a DOM document. Split out so that subclass can call.
*
* @param params Parameters including MathML
* @param result Blank result object
* @param start Request start time (milliseconds since epoch)
* @return Document or null if failed (in which case should return result)
*/
protected Document parseMathml(MathsImageParams params, MathsImageReturn result, long start)
throws Exception {
try {
Document mathml = parseMathml(params.getMathml());
if (SHOWPERFORMANCE) {
System.err.println("Parse DOM: " + (System.currentTimeMillis() - start));
}
return mathml;
} catch (SAXParseException e) {
int line = e.getLineNumber(), col = e.getColumnNumber();
result.setError("MathML parse error at " + line + ":" + col + " - " + e.getMessage());
return null;
}
}
/**
* Converts a colour from #rrggbb to Java Color object.
*
* @param rgb String e.g. #ff00ee
* @return Colour
* @throws IllegalArgumentException If colour string is not valid
*/
protected Color convertRgb(String rgb) throws IllegalArgumentException {
// Get colour parameter
Matcher m = REGEX_RGB.matcher(rgb);
if (!m.matches()) {
throw new IllegalArgumentException(
"MathML invalid colour '" + rgb + "'; expected #rrggbb (lower-case)");
}
return new Color(
Integer.parseInt(m.group(1), 16),
Integer.parseInt(m.group(2), 16),
Integer.parseInt(m.group(3), 16));
}
/**
* Does real work; separated out so it can be efficiently called from subclass.
*
* @param params Request parameters
* @param doc MathML as DOM document
* @param result Initialised result object with blank fields
* @param start Start time of request (milliseconds since epoch)
* @return Return result
* @throws IOException Any error creating image file
*/
protected MathsImageReturn getImage(
MathsImageParams params, Document doc, MathsImageReturn result, long start)
throws IOException {
initContext();
Color fg;
try {
fg = convertRgb(params.getRgb());
} catch (IllegalArgumentException e) {
result.setError(e.getMessage());
return result;
}
if (SHOWPERFORMANCE) {
System.err.println("Setup: " + (System.currentTimeMillis() - start));
}
// Parse XML to JEuclid document
DocumentElement document;
preprocessForJEuclid(doc);
document = DOMBuilder.getInstance().createJeuclidDom(doc);
if (SHOWPERFORMANCE) {
System.err.println("Parse: " + (System.currentTimeMillis() - start));
}
// Set layout options
LayoutContextImpl layout = new LayoutContextImpl(LayoutContextImpl.getDefaultLayoutContext());
layout.setParameter(Parameter.ANTIALIAS, Boolean.TRUE);
// This size is hardcoded to go well with our default text size
// and be one of the sizes that doesn't look too horrible.
layout.setParameter(Parameter.MATHSIZE, params.getSize() * 15f);
layout.setParameter(Parameter.SCRIPTSIZEMULTIPLIER, 0.86667f);
layout.setParameter(Parameter.MATHCOLOR, fg);
// These fonts are included with the JEuclid build so ought to work
layout.setParameter(
Parameter.FONTS_SERIF, Arrays.asList(new String[] {"DejaVu Serif", "Quivira"}));
layout.setParameter(Parameter.FONTS_SCRIPT, Arrays.asList(new String[] {"Allura"}));
layout.setParameter(Parameter.FONTS_SANSSERIF, "DejaVu Sans");
layout.setParameter(Parameter.FONTS_MONOSPACED, "DejaVu Sans Mono");
if (SHOWPERFORMANCE) {
System.err.println("Layout: " + (System.currentTimeMillis() - start));
}
// Layout equation
JEuclidView view = new JEuclidView(document, layout, context);
float ascent = view.getAscentHeight();
float descent = view.getDescentHeight();
float width = view.getWidth();
if (SHOWPERFORMANCE) {
System.err.println("View: " + (System.currentTimeMillis() - start));
}
// Create new image to hold it
int pixelWidth = Math.max(1, (int) Math.ceil(width)),
pixelHeight = Math.max(1, (int) Math.ceil(ascent + descent));
BufferedImage image = new BufferedImage(pixelWidth, pixelHeight, BufferedImage.TYPE_INT_ARGB);
if (SHOWPERFORMANCE) {
System.err.println("Image: " + (System.currentTimeMillis() - start));
}
view.draw(image.createGraphics(), 0, ascent);
if (SHOWPERFORMANCE) {
System.err.println("Draw: " + (System.currentTimeMillis() - start));
}
ByteArrayOutputStream output = new ByteArrayOutputStream();
ImageIO.write(image, "png", output);
if (SHOWPERFORMANCE) {
System.err.println("PNG: " + (System.currentTimeMillis() - start));
}
// Save results
result.setImage(output.toByteArray());
result.setBaseline(BigInteger.valueOf(image.getHeight() - (int) Math.round(ascent)));
result.setOk(true);
if (SHOWPERFORMANCE) {
System.err.println("End: " + (System.currentTimeMillis() - start));
}
return result;
}
/**
* Carries out preprocessing that makes JEuclid handle the document better.
*
* @param doc Document
*/
static void preprocessForJEuclid(Document doc) {
// underbrace and overbrace
NodeList list = doc.getElementsByTagName("mo");
for (int i = 0; i < list.getLength(); i++) {
Element mo = (Element) list.item(i);
String parentName = ((Element) mo.getParentNode()).getTagName();
if (parentName == null) {
continue;
}
if (parentName.equals("munder") && isTextChild(mo, "\ufe38")) {
mo.setAttribute("stretchy", "true");
mo.removeChild(mo.getFirstChild());
mo.appendChild(doc.createTextNode("\u23df"));
} else if (parentName.equals("mover") && isTextChild(mo, "\ufe37")) {
mo.setAttribute("stretchy", "true");
mo.removeChild(mo.getFirstChild());
mo.appendChild(doc.createTextNode("\u23de"));
}
}
// menclose for long division doesn't allow enough top padding. Oh, and
// <mpadded> isn't implemented. And there isn't enough padding to left of
// the bar either. Solve by adding an <mover> with just an <mspace> over#
// the longdiv, contained within an mrow that adds a <mspace> before it.
list = doc.getElementsByTagName("menclose");
for (int i = 0; i < list.getLength(); i++) {
Element menclose = (Element) list.item(i);
// Only for longdiv
if (!"longdiv".equals(menclose.getAttribute("notation"))) {
continue;
}
Element mrow = doc.createElementNS(WebMathsService.NS, "mrow");
Element mover = doc.createElementNS(WebMathsService.NS, "mover");
Element mspace = doc.createElementNS(WebMathsService.NS, "mspace");
Element mspaceW = doc.createElementNS(WebMathsService.NS, "mspace");
boolean previousElement = false;
for (Node previous = menclose.getPreviousSibling();
previous != null;
previous = previous.getPreviousSibling()) {
if (previous.getNodeType() == Node.ELEMENT_NODE) {
previousElement = true;
break;
}
}
if (previousElement) {
mspaceW.setAttribute("width", "4px");
}
menclose.getParentNode().insertBefore(mrow, menclose);
menclose.getParentNode().removeChild(menclose);
mrow.appendChild(mspaceW);
mrow.appendChild(mover);
mover.appendChild(menclose);
mover.appendChild(mspace);
}
}
private static boolean isTextChild(Node parent, String text) {
NodeList list = parent.getChildNodes();
if (list.getLength() != 1) {
return false;
}
Node child = list.item(0);
if (child.getNodeType() != Node.TEXT_NODE) {
return false;
}
return child.getNodeValue().equals(text);
}
/**
* Parses mathml from the input into a DOM document. Split out so that subclass can call.
*
* @param params Parameters including MathML
* @param result Blank result object
* @param start Request start time (milliseconds since epoch)
* @return Document or null if failed (in which case should return result)
*/
protected Document parseMathml(MathsEpsParams params, MathsEpsReturn result, long start)
throws Exception {
try {
Document mathml = parseMathml(params.getMathml());
if (SHOWPERFORMANCE) {
System.err.println("Parse DOM: " + (System.currentTimeMillis() - start));
}
return mathml;
} catch (SAXParseException e) {
int line = e.getLineNumber(), col = e.getColumnNumber();
result.setError("MathML parse error at " + line + ":" + col + " - " + e.getMessage());
return null;
}
}
/**
* Does real work; separated out so it can be efficiently called from subclass.
*
* @param params Request parameters
* @param doc MathML as DOM document
* @param result Initialised result object with blank fields
* @param start Start time of request (milliseconds since epoch)
* @return Return result
* @throws IOException Any error creating image file
*/
protected MathsEpsReturn getEps(
MathsEpsParams params, Document doc, MathsEpsReturn result, long start) throws IOException {
result.setError("EPS output from JEuclid not supported");
return result;
}
}
