X-Git-Url: http://jsfdemo.indexdata.com/?a=blobdiff_plain;f=src%2Forg%2Fz3950%2Fzing%2Fcql%2FCQLNode.java;h=5965da621c6eea1afa47700f5ebfad68da2e3d0d;hb=561a15208b3be53c0ad3a1eb5524badfc377c478;hp=3d16a37636653ddfbedcb760f30c67fa36997986;hpb=ac8fb2ba7ecad42eb920c65b7056e3a3e677275c;p=cql-java-moved-to-github.git

diff --git a/src/org/z3950/zing/cql/CQLNode.java b/src/org/z3950/zing/cql/CQLNode.java
index 3d16a37..5965da6 100644
--- a/src/org/z3950/zing/cql/CQLNode.java
+++ b/src/org/z3950/zing/cql/CQLNode.java
@@ -1,61 +1,96 @@
-// $Id: CQLNode.java,v 1.6 2002-10-29 10:15:58 mike Exp $
+// $Id: CQLNode.java,v 1.15 2002-11-20 01:15:15 mike Exp $
 
 package org.z3950.zing.cql;
+import java.util.Properties;
+import java.util.Vector;
 
 
 /**
- * Represents a node in a CQL parse-tree ...
- * ###
+ * Represents a node in a CQL parse-tree.
  *
- * @version	$Id: CQLNode.java,v 1.6 2002-10-29 10:15:58 mike Exp $
+ * @version	$Id: CQLNode.java,v 1.15 2002-11-20 01:15:15 mike Exp $
  */
 public abstract class CQLNode {
-    abstract String toXCQL(int level);
-    abstract String toCQL();
+    CQLNode() {}		// prevent javadoc from documenting this
 
-    protected String indent(int level) {
-	String x = "";
-	while (level-- > 0) {
-	    x += "  ";
-	}
-	return x;
+    /**
+     * Translates a parse-tree into an XCQL document.
+     * <P>
+     * @param level
+     *	The number of levels to indent the top element of the XCQL
+     *	document.  This will typically be 0 when invoked by an
+     *	application; it takes higher values when this method is
+     *	invoked recursively for nodes further down the tree.
+     * @return
+     *	A String containing an XCQL document equivalent to the
+     *	parse-tree whose root is this node.
+     */
+    public String toXCQL(int level) {
+	return toXCQL(level, new Vector());
     }
 
-    // XML Quote --
-    //	s/&/&amp;/g;
-    //	s/</&lt;/g;
-    //	s/>/&gt;/g;
-    // This is hideously inefficient, but I just don't see a better
-    // way using the standard JAVA library.
-    //
-    protected String xq(String str) {
-	str = replace(str, "&", "&amp;");
-	str = replace(str, "<", "&lt;");
-	str = replace(str, ">", "&gt;");
-	return str;
+    abstract public String toXCQL(int level, Vector prefixes);
+
+    protected static String renderPrefixes(int level, Vector prefixes) {
+	if (prefixes.size() == 0)
+	    return "";
+	String res = indent(level) + "<prefixes>\n";
+	for (int i = 0; i < prefixes.size(); i++) {
+	    CQLPrefix p = (CQLPrefix) prefixes.get(i);
+	    res += indent(level+1) + "<prefix>\n";
+	    if (p.name != null)
+		res += indent(level+2) + "<name>" + p.name + "</name>\n";
+	    res += indent(level+2) +
+		"<identifier>" + p.identifier + "</identifier>\n";
+	    res += indent(level+1) + "</prefix>\n";
+	}
+	return res + indent(level) + "</prefixes>\n";
     }
 
-    String replace(String str, String from, String to) {
-	StringBuffer sb = new StringBuffer();
-	int ix;			// index of next `from'
-	int offset = 0;		// index of previous `from' + length(from)
+    /**
+     * Decompiles a parse-tree into a CQL query.
+     * <P>
+     * @return
+     *	A String containing a CQL query equivalent to the parse-tree
+     *	whose root is this node, so that compiling that query will
+     *	yield an identical tree.
+     */
+    abstract public String toCQL();
 
-	while ((ix = str.indexOf(from, offset)) != -1) {
-	    sb.append(str.substring(offset, ix));
-	    sb.append(to);
-	    offset = ix + from.length();
-	}
+    /**
+     * Renders a parse-tree into a Yaz-style PQF string.
+     * PQF, or Prefix Query Format, is a cryptic but powerful notation
+     * that can be trivially mapped, one-to-one, int Z39.50 Type-1 and
+     * Type-101 queries.  A specification for the format can be found
+     * in
+     * <A href="http://indexdata.dk/yaz/doc/tools.php#PQF"
+     *	>Chapter 7 (Supporting Tools)</A> of the
+     * <A href="http://indexdata.dk/yaz/">YAZ</A> manual.
+     * <P>
+     * @param config
+     *	A <TT>Properties</TT> object containing configuration
+     *	information that specifies the mapping from CQL qualifiers,
+     *	relations, etc. to Type-1 attributes.  The mapping
+     *	specification is described in the cql-java distribution's
+     *	sample PQF-mapping configuration file,
+     *	<TT>etc/pqf.properties</TT>, which see.
+     * @return
+     *	A String containing a PQF query equivalent to the parse-tree
+     *	whose root is this node.  This may be fed into the tool of
+     *	your choice to obtain a BER-encoded packet.
+     */
+    abstract public String toPQF(Properties config)
+	throws PQFTranslationException;
 
-	// End of string: append last bit and we're done
-	sb.append(str.substring(offset));
-	return sb.toString();
-    }
+    /**
+     * Returns a String of spaces for indenting to the specified level.
+     */
+    protected static String indent(int level) { return Utils.indent(level); }
 
-    // Test harness
-    public static void main (String[] args) {
-	CQLNode n1 = new CQLTermNode("dc.author", "=", "kernighan");
-	CQLNode n2 = new CQLTermNode("dc.title", "all", "elements style");
-	CQLNode root = new CQLAndNode(n1, n2);
-	System.out.println(root.toXCQL(0));
-    }
+    /**
+     * Returns the argument String quoted for XML.
+     * For example, each occurrence of <TT>&lt;</TT> is translated to
+     * <TT>&amp;lt;</TT>.
+     */
+    protected static String xq(String str) { return Utils.xq(str); }
 }