set_var_from_query

set_var_from_query.patch

Index: src/henplus/commands/SetCommand.java
===================================================================
RCS file: /cvsroot/henplus/henplus/src/henplus/commands/SetCommand.java,v
retrieving revision 1.25
diff -u -r1.25 SetCommand.java
--- src/henplus/commands/SetCommand.java	29 Nov 2006 17:57:53 -0000	1.25
+++ src/henplus/commands/SetCommand.java	7 Jan 2008 13:19:35 -0000
@@ -17,6 +17,9 @@
 import henplus.view.TableRenderer;
 import henplus.view.util.SortedMatchIterator;
 
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -33,6 +36,7 @@
     private final static String SETTINGS_FILENAME = "settings";
     private final static String SPECIAL_LAST_COMMAND="_HENPLUS_LAST_COMMAND";
     private final static ColumnMetaData[] SET_META;
+    private static final String VAR_FROM_QUERY_COMMAND = "set-var-from-query";
 
     static {
 	SET_META = new ColumnMetaData[2];
@@ -50,7 +54,7 @@
      */
     public String[] getCommandList() {
 	return new String[] {
-	    "set-var", "unset-var", "unset-all"
+	    "set-var", VAR_FROM_QUERY_COMMAND, "unset-var", "unset-all"
 	};
     }
     
@@ -75,7 +79,9 @@
             });
     }
 
-    public boolean requiresValidSession(String cmd) { return false; }
+    public boolean requiresValidSession(String cmd) {
+        return VAR_FROM_QUERY_COMMAND.equals(cmd); 
+    }
 
     public Map getVariableMap() {
 	return _variables;
@@ -88,7 +94,7 @@
 	StringTokenizer st = new StringTokenizer(param);
 	int argc = st.countTokens();
 	
-	if ("set-var".equals(cmd)) {
+	if ("set-var".equals(cmd) || VAR_FROM_QUERY_COMMAND.equals(cmd)) {
             /*
              * no args. only show.
              */
@@ -138,7 +144,16 @@
 		else if (value.startsWith("\'") && value.endsWith("\'")) {
 		    value = value.substring(1, value.length()-1);
 		}
-                setVariable(varname, value);
+        if ("set-var".equals(cmd)) {
+            setVariable(varname, value);
+        } else if (VAR_FROM_QUERY_COMMAND.equals(cmd)) {
+            try {
+                setVariable(varname, executeSQL(currentSession, value));
+            } catch (SQLException e) {
+                System.err.println("Could not set " + varname + ". " + e.getMessage());
+                return EXEC_FAILED;
+            }
+        }
 		return SUCCESS;
 	    }
 	    return SYNTAX_ERROR;
@@ -169,6 +184,21 @@
 	}
 	return SUCCESS;
     }
+    
+    private static String executeSQL(SQLSession currentSession, String sql) throws SQLException {
+        Statement stmt = currentSession.createStatement();
+        ResultSet rs = stmt.executeQuery(sql);
+        String result = sql;
+        
+        if (!rs.next()) {
+            throw new SQLException("No row could be selected.");
+        }
+        result = rs.getObject(1).toString();
+        
+        rs.close();
+        stmt.close();
+        return result;
+    }
 
     private void setVariable(String name, String value) {
         _variables.put(name, value);
@@ -205,7 +235,7 @@
 	String cmd = (String) st.nextElement();
 	int argc = st.countTokens();
 	final HashSet  alreadyGiven = new HashSet();
-	if ("set-var".equals(cmd)) {
+	if ("set-var".equals(cmd) || VAR_FROM_QUERY_COMMAND.equals(cmd)) {
 	    if (argc > ("".equals(lastWord) ? 0 : 1)) {
 		return null;
 	    }
@@ -250,6 +280,9 @@
 	if ("set-var".equals(cmd)) {
 	    return cmd + " [<varname> <value>]"; 
 	}
+    else if (VAR_FROM_QUERY_COMMAND.equals(cmd)) {
+        return cmd + " [<varname> <sql query>]";
+    }
 	else if ("unset-var".equals(cmd)) {
 	    return cmd + " <varname> [<varname> ..]";
 	}
@@ -275,6 +308,22 @@
 		+"\tIf you want to quote the dollarsign explicitly, write\n"
 		+"\ttwo dollars: $$FOO means $FOO";
 	}
+    else if (VAR_FROM_QUERY_COMMAND.equals(cmd)) {
+        dsc= "\tWithout parameters,  show all  variable settings.  With\n"
+            +"\tparameters, set variable with name <varname> to value which\n"
+            +"\tis retrieved from the sql query. The first colomn from the\n"
+            +"\tfirst row is used to set the variable.\n"
+            +"\tVariables are  expanded in any  command you issue on the\n"
+            +"\tcommandline.  Variable expansion works like on the shell\n"
+            +"\twith the dollarsign. Both forms, $VARNAME and ${VARNAME},\n"
+            +"\tare supported.  If the variable is  _not_  set, then the\n"
+            +"\ttext is  left untouched.  So  if  there  is  no variable\n"
+            +"\t$VARNAME, then it is not replaced by an empty string but\n"
+            +"\tstays '$VARNAME'. This is because some scripts use wierd\n"
+            +"\tidentifiers  containting  dollars  (esp. Oracle scripts)\n"
+            +"\tIf you want to quote the dollarsign explicitly, write\n"
+            +"\ttwo dollars: $$FOO means $FOO";
+    }
 	else if ("unset-var".equals(cmd)) {
 	    dsc="\tunset the variable with name <varname>. You may provide\n"
 		+"\tmultiple variables to be unset.";