org.mybatis.scripting.velocity.RepeatDirective Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of mybatis-velocity Show documentation
Show all versions of mybatis-velocity Show documentation
Velocity support for MyBatis
/**
* Copyright 2012-2018 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.mybatis.scripting.velocity;
import java.io.IOException;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Iterator;
import org.apache.velocity.context.ChainedInternalContextAdapter;
import org.apache.velocity.context.InternalContextAdapter;
import org.apache.velocity.exception.TemplateInitException;
import org.apache.velocity.exception.VelocityException;
import org.apache.velocity.runtime.RuntimeServices;
import org.apache.velocity.runtime.directive.Directive;
import org.apache.velocity.runtime.directive.Scope;
import org.apache.velocity.runtime.directive.StopCommand;
import org.apache.velocity.runtime.parser.node.ASTReference;
import org.apache.velocity.runtime.parser.node.ASTStringLiteral;
import org.apache.velocity.runtime.parser.node.Node;
import org.apache.velocity.runtime.parser.node.ParserTreeConstants;
import org.apache.velocity.util.introspection.Info;
/**
* #repeat($collection $item SEP OPEN CLOSE).
*/
public class RepeatDirective extends Directive {
protected static final int MAX_IN_CLAUSE_SIZE = 1000;
/** Immutable fields */
private String var;
private String open = "";
private String close = "";
private String separator = "";
protected Info uberInfo;
@Override
public String getName() {
return "repeat";
}
@Override
public void init(RuntimeServices rs, InternalContextAdapter context, Node node) {
super.init(rs, context, node);
final int n = node.jjtGetNumChildren() - 1;
for (int i = 1; i < n; i++) {
Node child = node.jjtGetChild(i);
if (i == 1) {
if (child.getType() == ParserTreeConstants.JJTREFERENCE) {
this.var = ((ASTReference) child).getRootString();
} else {
throw new TemplateInitException("Syntax error", getTemplateName(), getLine(), getColumn());
}
} else if (child.getType() == ParserTreeConstants.JJTSTRINGLITERAL) {
String value = (String) ((ASTStringLiteral) child).value(context);
switch (i) {
case 2:
this.separator = value;
break;
case 3:
this.open = value;
break;
case 4:
this.close = value;
break;
default:
break;
}
} else {
throw new TemplateInitException("Syntax error", getTemplateName(), getLine(), getColumn());
}
}
this.uberInfo = new Info(this.getTemplateName(), getLine(), getColumn());
}
@Override
public boolean render(InternalContextAdapter context, Writer writer, Node node) throws IOException {
Object listObject = node.jjtGetChild(0).value(context);
if (listObject == null) {
return false;
}
Iterator i = null;
try {
i = this.rsvc.getUberspect().getIterator(listObject, this.uberInfo);
} catch (RuntimeException e) {
throw e;
} catch (Exception ee) {
String msg = "Error getting iterator for #repeat at " + this.uberInfo;
this.rsvc.getLog().error(msg, ee);
throw new VelocityException(msg, ee);
}
if (i == null) {
throw new VelocityException("Invalid collection");
}
int counter = 0;
boolean maxNbrLoopsExceeded = false;
Object o = context.get(this.var);
ParameterMappingCollector collector = (ParameterMappingCollector) context
.get(SQLScriptSource.MAPPING_COLLECTOR_KEY);
String savedItemKey = collector.getItemKey();
collector.setItemKey(this.var);
RepeatScope foreach = new RepeatScope(this, context.get(getName()), this.var);
context.put(getName(), foreach);
NullHolderContext nullHolderContext = null;
StringWriter buffer = new StringWriter();
while (!maxNbrLoopsExceeded && i.hasNext()) {
Object value = i.next();
put(context, this.var, value);
foreach.index++;
foreach.hasNext = i.hasNext();
try {
if (value == null) {
if (nullHolderContext == null) {
nullHolderContext = new NullHolderContext(this.var, context);
}
node.jjtGetChild(node.jjtGetNumChildren() - 1).render(nullHolderContext, buffer);
} else {
node.jjtGetChild(node.jjtGetNumChildren() - 1).render(context, buffer);
}
} catch (StopCommand stop) {
if (stop.isFor(this)) {
break;
}
clean(context, o, collector, savedItemKey);
// close does not perform any action and this is here
// to avoid eclipse reporting possible leak.
buffer.close();
throw stop;
}
counter++;
maxNbrLoopsExceeded = counter >= MAX_IN_CLAUSE_SIZE;
if (i.hasNext() && !maxNbrLoopsExceeded) {
buffer.append(this.separator);
}
}
String content = buffer.toString().trim();
if (!"".equals(content)) {
writer.append(this.open);
writer.append(content);
writer.append(this.close);
}
clean(context, o, collector, savedItemKey);
return true;
}
protected void clean(InternalContextAdapter context, Object o, ParameterMappingCollector collector,
String savedItemKey) {
if (o != null) {
context.put(this.var, o);
} else {
context.remove(this.var);
}
collector.setItemKey(savedItemKey);
postRender(context);
}
protected void put(InternalContextAdapter context, String key, Object value) {
context.put(key, value);
}
@Override
public int getType() {
return BLOCK;
}
public static class RepeatScope extends Scope {
protected int index = -1;
protected boolean hasNext = false;
protected final String var;
public RepeatScope(Object newOwner, Object replaces, String newVar) {
super(newOwner, replaces);
this.var = newVar;
}
public int getIndex() {
return this.index;
}
public int getCount() {
return this.index + 1;
}
public boolean hasNext() {
return getHasNext();
}
public boolean getHasNext() {
return this.hasNext;
}
public boolean isFirst() {
return this.index < 1;
}
public boolean getFirst() {
return isFirst();
}
public boolean isLast() {
return !this.hasNext;
}
public boolean getLast() {
return isLast();
}
public String getVar() {
return this.var;
}
}
protected static class NullHolderContext extends ChainedInternalContextAdapter {
private String loopVariableKey = "";
private boolean active = true;
protected NullHolderContext(String key, InternalContextAdapter context) {
super(context);
if (key != null) {
this.loopVariableKey = key;
}
}
@Override
public Object get(String key) {
return (this.active && this.loopVariableKey.equals(key)) ? null : super.get(key);
}
@Override
public Object put(String key, Object value) {
if (this.loopVariableKey.equals(key) && (value == null)) {
this.active = true;
}
return super.put(key, value);
}
@Override
public Object remove(String key) {
if (this.loopVariableKey.equals(key)) {
this.active = false;
}
return super.remove(key);
}
}
@Override
public boolean isScopeProvided() {
return true;
}
}