package org.lilystudio.smarty4j.statement.function;
import static org.objectweb.asm.Opcodes.*;
import java.util.List;
import java.util.Map;
import org.lilystudio.smarty4j.Context;
import org.lilystudio.smarty4j.ParseException;
import org.lilystudio.smarty4j.Template;
import org.lilystudio.smarty4j.expression.IExpression;
import org.lilystudio.smarty4j.statement.Block;
import org.lilystudio.smarty4j.statement.BlockStatement;
import org.lilystudio.smarty4j.statement.IBlockFunction;
import org.lilystudio.smarty4j.statement.ILoop;
import org.lilystudio.smarty4j.statement.IStatement;
import org.lilystudio.smarty4j.statement.ParameterCharacter;
import org.objectweb.asm.Label;
import org.objectweb.asm.MethodVisitor;
/**
* 循环函数。
*
* <pre>
* from--待循环的数据集合，可以是数组，LIST/MAP或者单一对象
* item--当前获得的单个数据，$item是from中的一个元素
* key--如果是数组，LIST类的，$key就是当前的序号，如果是MAP，$key就是item对应的主键值
*
* {assign var="animals" value="Rat,Ox,Tiger,Hare,Dragon,Serpent,Horse,Sheep,Monkey,Rooster,Dog,Boar" delimiter=","}
* {foreach from=$animals item="item" key="key"}{$key}{$item}
* {/foreach}
* </pre>
*
* <b>OUTPUT:</b>
*
* <pre>
* 0:Rat
* 1:Ox
* 2:Tiger
* 3:Hare
* 4:Dragon
* 5:Serpent
* 6:Horse
* 7:Sheep
* 8:Monkey
* 9:Rooster
* 10:Dog
* 11:Boar
* </pre>
*
* @version 1.0.0, 2010/10/01
* @author 欧阳先伟
* @since Smarty 1.0
*/
public class $foreach extends Block implements ILoop {
/** ASM名称 */
public static final String NAME = $foreach.class.getName().replace('.', '/');
/** 参数定义 */
private static ParameterCharacter[] definitions = {
new ParameterCharacter(ParameterCharacter.OBJECT, "from"),
new ParameterCharacter(ParameterCharacter.STRING, "item"),
new ParameterCharacter(ParameterCharacter.STRING, null, "key"),
new ParameterCharacter(ParameterCharacter.STRING, null, "name") };
/**
* 获取一个循环体源对象包含的对象数组, 如果源对象是Map, 将取回关键字对应的数组,
* 如果无法将源对象转换成等价的对象数组, 源对象将直接被返回
*
* @param o
* 需要循环的源对象
* @return 源对象数组
*/
public static Object[] getLooper(Object o) {
if (o instanceof List) {
return ((List<?>) o).toArray();
} else if (o instanceof Object[]) {
return (Object[]) o;
} else if (o instanceof Map) {
return ((Map<?, ?>) o).entrySet().toArray();
} else {
return new Object[] { o };
}
}
/** 循环开始标签 */
private Label startLabel = new Label();
/** 循环结束标签 */
private Label endLabel = new Label();
/** 循环体为空时对应的区块 */
private IBlockFunction elseBlock;
public Label getStartLabel() {
return startLabel;
}
public Label getEndLabel() {
return endLabel;
}
public void restore(MethodVisitor mw, Map<String, Integer> variableNames) {
mw.visitInsn(POP2);
if (variableNames == null) {
if (getParameter(2) != null) {
mw.visitMethodInsn(INVOKEVIRTUAL, Context.NAME, "set",
"(Ljava/lang/String;Ljava/lang/Object;)V");
}
mw.visitMethodInsn(INVOKEVIRTUAL, Context.NAME, "set",
"(Ljava/lang/String;Ljava/lang/Object;)V");
}
}
@Override
public void addStatement(IStatement statement) throws ParseException {
if (statement instanceof $foreachelse) {
if (elseBlock != null) {
throw new ParseException("不能重复定义foreachelse");
} else {
elseBlock = new BlockStatement();
elseBlock.setParent(this.getParent());
}
} else if (elseBlock != null) {
elseBlock.addStatement(statement);
} else {
super.addStatement(statement);
}
}
public ParameterCharacter[] getDefinitions() {
return definitions;
}
@Override
public void scan(Template template) {
super.scan(template);
if (elseBlock != null) {
elseBlock.scan(template);
}
}
@Override
public void parse(MethodVisitor mw, int local,
Map<String, Integer> variableNames) {
Integer oldItemValue = null;
Integer oldKeyValue = null;
IExpression item = getParameter(1);
IExpression key = getParameter(2);
Label isnull = new Label();
Label isnotmap = new Label();
Label loopinit = new Label();
Label setstart = new Label();
Label setend = new Label();
Label setlist = new Label();
Label loopend = new Label();
Label end = new Label();
getParameter(0).parseObject(mw, local, variableNames);
mw.visitVarInsn(ASTORE, local);
mw.visitVarInsn(ALOAD, local);
mw.visitJumpInsn(IFNULL, isnull);
if (variableNames != null) {
oldItemValue = variableNames.get(item.toString());
variableNames.put(item.toString(), Integer.valueOf(local + 1));
if (key != null) {
oldKeyValue = variableNames.get(key.toString());
variableNames.put(key.toString(), Integer.valueOf(local + 2));
}
} else {
// 保存原始的循环变量名值
mw.visitVarInsn(ALOAD, CONTEXT);
item.parse(mw, local + 1, variableNames);
mw.visitInsn(DUP2);
mw.visitMethodInsn(INVOKEVIRTUAL, Context.NAME, "get",
"(Ljava/lang/String;)Ljava/lang/Object;");
if (key != null) {
mw.visitVarInsn(ALOAD, CONTEXT);
key.parse(mw, local + 2, variableNames);
mw.visitInsn(DUP2);
mw.visitMethodInsn(INVOKEVIRTUAL, Context.NAME, "get",
"(Ljava/lang/String;)Ljava/lang/Object;");
}
}
mw.visitVarInsn(ALOAD, local);
mw.visitMethodInsn(INVOKESTATIC, NAME, "getLooper",
"(Ljava/lang/Object;)[Ljava/lang/Object;");
mw.visitVarInsn(ALOAD, local);
mw.visitTypeInsn(INSTANCEOF, "java/util/Map");
mw.visitJumpInsn(IFEQ, isnotmap);
mw.visitVarInsn(ALOAD, local);
mw.visitTypeInsn(CHECKCAST, "java/util/Map");
mw.visitJumpInsn(GOTO, loopinit);
mw.visitLabel(isnotmap);
mw.visitInsn(ACONST_NULL);
mw.visitLabel(loopinit);
mw.visitVarInsn(ASTORE, local);
mw.visitInsn(DUP);
mw.visitInsn(ARRAYLENGTH);
mw.visitInsn(ICONST_0);
mw.visitVarInsn(ISTORE, local + 3);
mw.visitLabel(setstart);
mw.visitInsn(DUP2);
mw.visitVarInsn(ILOAD, local + 3);
mw.visitJumpInsn(IF_ICMPEQ, loopend);
if (getParameter(3) != null) {
mw.visitVarInsn(ASTORE, local + 4);
mw.visitInsn(DUP);
mw.visitVarInsn(ALOAD, CONTEXT);
mw.visitInsn(SWAP);
getParameter(3).parse(mw, local + 5, variableNames);
mw.visitVarInsn(ILOAD, local + 3);
mw.visitMethodInsn(INVOKEVIRTUAL, Context.NAME, "setForeach",
"(ILjava/lang/String;I)V");
mw.visitVarInsn(ALOAD, local + 4);
}
if (variableNames == null) {
mw.visitVarInsn(ALOAD, CONTEXT);
mw.visitInsn(SWAP);
item.parse(mw, local + 4, variableNames);
mw.visitInsn(SWAP);
}
mw.visitVarInsn(ILOAD, local + 3);
mw.visitInsn(AALOAD);
mw.visitVarInsn(ALOAD, local);
mw.visitJumpInsn(IFNULL, setlist);
// 循环源集合是Map型时所执行的处理
if (key != null) {
mw.visitInsn(DUP);
mw.visitMethodInsn(INVOKEINTERFACE, "java/util/Map$Entry", "getKey",
"()Ljava/lang/Object;");
// 是否设置主键的值
if (variableNames != null) {
mw.visitVarInsn(ASTORE, local + 2);
} else {
mw.visitVarInsn(ALOAD, CONTEXT);
mw.visitInsn(SWAP);
key.parse(mw, local + 4, variableNames);
mw.visitInsn(SWAP);
mw.visitMethodInsn(INVOKEVIRTUAL, Context.NAME, "set",
"(Ljava/lang/String;Ljava/lang/Object;)V");
}
}
mw.visitMethodInsn(INVOKEINTERFACE, "java/util/Map$Entry", "getValue",
"()Ljava/lang/Object;");
mw.visitJumpInsn(GOTO, setend);
// 循环源集合是List型时所执行的处理
mw.visitLabel(setlist);
if (key != null) {
if (variableNames == null) {
// 是否设置主键的值, 按数字编号
mw.visitVarInsn(ALOAD, CONTEXT);
key.parse(mw, local + 4, variableNames);
}
mw.visitVarInsn(ILOAD, local + 3);
mw.visitMethodInsn(INVOKESTATIC, "java/lang/Integer", "valueOf",
"(I)Ljava/lang/Integer;");
if (variableNames != null) {
mw.visitVarInsn(ASTORE, local + 2);
} else {
mw.visitMethodInsn(INVOKEVIRTUAL, Context.NAME, "set",
"(Ljava/lang/String;Ljava/lang/Object;)V");
}
}
mw.visitLabel(setend);
if (variableNames != null) {
mw.visitVarInsn(ASTORE, local + 1);
} else {
mw.visitMethodInsn(INVOKEVIRTUAL, Context.NAME, "set",
"(Ljava/lang/String;Ljava/lang/Object;)V");
}
super.parse(mw, local + 4, variableNames);
mw.visitLabel(startLabel);
mw.visitIincInsn(local + 3, 1);
mw.visitJumpInsn(GOTO, setstart);
mw.visitLabel(loopend);
mw.visitInsn(POP);
// 循环结束, 恢复恢复过程中被设置的属性的原始值
mw.visitLabel(endLabel);
restore(mw, variableNames);
mw.visitJumpInsn(GOTO, end);
// 循环源集合为空时的处理
mw.visitLabel(isnull);
if (elseBlock != null) {
elseBlock.parse(mw, local, variableNames);
}
mw.visitLabel(end);
if (variableNames != null) {
variableNames.put(item.toString(), oldItemValue);
if (key != null) {
variableNames.put(key.toString(), oldKeyValue);
}
}
}
}