001: /*
002: * Copyright (c) 2003 The Visigoth Software Society. All rights
003: * reserved.
004: *
005: * Redistribution and use in source and binary forms, with or without
006: * modification, are permitted provided that the following conditions
007: * are met:
008: *
009: * 1. Redistributions of source code must retain the above copyright
010: * notice, this list of conditions and the following disclaimer.
011: *
012: * 2. Redistributions in binary form must reproduce the above copyright
013: * notice, this list of conditions and the following disclaimer in
014: * the documentation and/or other materials provided with the
015: * distribution.
016: *
017: * 3. The end-user documentation included with the redistribution, if
018: * any, must include the following acknowledgement:
019: * "This product includes software developed by the
020: * Visigoth Software Society (http://www.visigoths.org/)."
021: * Alternately, this acknowledgement may appear in the software itself,
022: * if and wherever such third-party acknowledgements normally appear.
023: *
024: * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
025: * project contributors may be used to endorse or promote products derived
026: * from this software without prior written permission. For written
027: * permission, please contact visigoths@visigoths.org.
028: *
029: * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
030: * nor may "FreeMarker" or "Visigoth" appear in their names
031: * without prior written permission of the Visigoth Software Society.
032: *
033: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
034: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
035: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
036: * DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
037: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
038: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
039: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
040: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
041: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
042: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
043: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
044: * SUCH DAMAGE.
045: * ====================================================================
046: *
047: * This software consists of voluntary contributions made by many
048: * individuals on behalf of the Visigoth Software Society. For more
049: * information on the Visigoth Software Society, please see
050: * http://www.visigoths.org/
051: */
052:
053: package freemarker.core;
054:
055: import freemarker.template.*;
056:
057: /**
058: * An instruction that assigns a literal or reference, to a single-identifier
059: * variable.
060: */
061: final class Assignment extends TemplateElement {
062:
063: private String variableName;
064: private Expression value, namespaceExp;
065: private int scope;
066:
067: static final int NAMESPACE = 1;
068: static final int LOCAL = 2;
069: static final int GLOBAL = 3;
070:
071: /**
072: * @param variableName the variable name to assign to.
073: * @param value the expression to assign.
074: * @param scope the scope of the assignment, one of NAMESPACE, LOCAL, or GLOBAL
075: */
076: Assignment(String variableName, Expression value, int scope) {
077: this .variableName = variableName;
078: this .value = value;
079: this .scope = scope;
080: }
081:
082: void setNamespaceExp(Expression namespaceExp) {
083: this .namespaceExp = namespaceExp;
084: }
085:
086: void accept(Environment env) throws TemplateException {
087: TemplateModel tm = value.getAsTemplateModel(env);
088: Environment.Namespace namespace = null;
089: if (namespaceExp != null) {
090: boolean oops = false;
091: try {
092: namespace = (Environment.Namespace) namespaceExp
093: .getAsTemplateModel(env);
094: } catch (ClassCastException cce) {
095: oops = true;
096: }
097: if (oops || namespace == null) {
098: throw new InvalidReferenceException(getStartLocation()
099: + "\nInvalid reference to namespace: "
100: + namespaceExp, env);
101: }
102: }
103: if (tm == null) {
104: if (env.isClassicCompatible()) {
105: tm = TemplateScalarModel.EMPTY_STRING;
106: } else {
107: String msg = "Error " + getStartLocation() + "\n"
108: + value + " is undefined."
109: + "\nIt cannot be assigned to " + variableName;
110: throw new InvalidReferenceException(msg, env);
111: }
112: }
113: if (scope == LOCAL) {
114: env.setLocalVariable(variableName, tm);
115: } else {
116: if (namespace == null) {
117: if (scope == GLOBAL) {
118: namespace = env.getGlobalNamespace();
119: } else if (scope == NAMESPACE) {
120: namespace = env.getCurrentNamespace();
121: }
122: }
123: namespace.put(variableName, tm);
124: }
125: }
126:
127: public String getCanonicalForm() {
128: StringBuffer buf = new StringBuffer();
129: if (!(parent instanceof AssignmentInstruction)) {
130: if (scope == LOCAL) {
131: buf.append("<#local ");
132: } else if (scope == GLOBAL) {
133: buf.append("<#global ");
134: } else {
135: buf.append("<#assign ");
136: }
137: }
138: buf.append(variableName);
139: buf.append('=');
140: buf.append(value.getCanonicalForm());
141: if (!(parent instanceof AssignmentInstruction)) {
142: if (namespaceExp != null) {
143: buf.append(" in ");
144: buf.append(namespaceExp.getCanonicalForm());
145: }
146: buf.append(">");
147: }
148: return buf.toString();
149: }
150:
151: public String getDescription() {
152: String s = "";
153: if (!(parent instanceof AssignmentInstruction)) {
154: s = "assignment: ";
155: if (scope == LOCAL) {
156: s = "local " + s;
157: } else if (scope == GLOBAL) {
158: s = "global " + s;
159: }
160: }
161: return s + variableName + "=" + value;
162: }
163: }
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