org.directwebremoting.extend.InboundVariable Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of dwr Show documentation
Show all versions of dwr Show documentation
DWR is easy Ajax for Java. It makes it simple to call Java code directly from Javascript.
It gets rid of almost all the boiler plate code between the web browser and your Java code.
/*
* Copyright 2005 Joe Walker
*
* 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.directwebremoting.extend;
import java.util.StringTokenizer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.directwebremoting.dwrp.ParseUtil;
import org.directwebremoting.dwrp.ProtocolConstants;
import org.directwebremoting.json.InvalidJsonException;
import org.directwebremoting.json.JsonArray;
import org.directwebremoting.json.JsonBoolean;
import org.directwebremoting.json.JsonHack;
import org.directwebremoting.json.JsonNull;
import org.directwebremoting.json.JsonNumber;
import org.directwebremoting.json.JsonObject;
import org.directwebremoting.json.JsonString;
import org.directwebremoting.json.JsonValue;
import org.directwebremoting.util.LocalUtil;
import org.directwebremoting.util.Messages;
/**
* A simple struct to hold data about a single converted javascript variable.
* An inbound variable will have either a value or a fileValue but not both.
* If file is true fileValue will be populated, otherwise value
* will be populated.
* @author Joe Walker [joe at getahead dot ltd dot uk]
*/
public final class InboundVariable
{
/**
* Parsing ctor
* @param context How we lookup references
* @param key The name of the variable that this was transfered as
* @param type The type information from javascript
* @param value The javascript variable converted to a string
*/
public InboundVariable(InboundContext context, String key, String type, String value)
{
this(context, key, type, new FormField(value));
}
/**
* Parsing ctor
* @param context How we lookup references
* @param key The name of the variable that this was transfered as
* @param type The type information from javascript
* @param fileValue The javascript variable converted to a FormField
*/
public InboundVariable(InboundContext context, String key, String type, FormField fileValue)
{
this.context = context;
this.type = type;
this.formField = fileValue;
this.key = key;
}
/**
* Attempt to de-reference an inbound variable.
* We try de-referencing as soon as possible (why? there is a good reason
* for it, it fixes some bug, but I can't remember what right now) However
* the referenced variable may not exist yet, so the de-referencing may
* fail, requiring us to have another go later.
* @throws MarshallException If cross-references don't add up
*/
public void dereference() throws MarshallException
{
int maxDepth = 0;
while (ProtocolConstants.TYPE_REFERENCE.equals(type))
{
InboundVariable cd = context.getInboundVariable(formField.getString());
if (cd == null)
{
throw new MarshallException(getClass(), Messages.getString("InboundVariable.MissingVariable", formField.getString()));
}
type = cd.type;
formField = cd.getFormField();
// For some reason we used to leave this until the loop finished
// and then only set it if the key was null. I think this logic
// may have been broken by named objects
key = cd.key;
maxDepth++;
if (maxDepth > 20)
{
throw new MarshallException(getClass(), "Max depth exceeded when dereferencing " + formField.getString());
}
}
// For references without an explicit variable name, we use the
// name of the thing they point at
// if (key == null)
// {
// key = formField.getString();
// }
}
/**
* @return Returns the lookup table.
*/
public InboundContext getLookup()
{
return context;
}
/**
* If we are using object parameters that have specified types then the
* {@link ConverterManager} will need to get to know what the required type
* is.
* @return The requested object type, or null if one was not specified
*/
public String getNamedObjectType()
{
if (type.startsWith("Object_"))
{
return type.substring("Object_".length());
}
else
{
return null;
}
}
public enum OnJsonParseError
{
/**
* If there is anything about the {@link InboundVariable} that can not
* be represented in 100% pure JSON, then throw
*/
Throw,
/**
* If there is anything about the {@link InboundVariable} that can not
* be represented in 100% pure JSON, then insert null and carry on
*/
Skip,
/**
* If there is anything about the {@link InboundVariable} that can not
* be represented in 100% pure JSON, then find some hack to do the best
* we can and carry on. This option may produce invalid JSON
*/
Hack,
}
/**
* Convert the set of {@link InboundVariable}s to JSON
* @return This object in JSON
* @throws InvalidJsonException If this can't be represented as JSON
*/
public JsonValue getJsonValue(OnJsonParseError onError) throws InvalidJsonException
{
return getJsonValue(onError, 0);
}
/**
* Convert the set of {@link InboundVariable}s to JSON
* @return This object in JSON
* @throws InvalidJsonException If this can't be represented as JSON
*/
private JsonValue getJsonValue(OnJsonParseError onError, int currentDepth) throws InvalidJsonException
{
if (currentDepth > 50)
{
throw new InvalidJsonException("JSON structure too deeply nested. Is it recursive?");
}
String value = getValue();
if (type.equalsIgnoreCase("boolean"))
{
return new JsonBoolean(Boolean.parseBoolean(value));
}
else if (type.equalsIgnoreCase("number"))
{
return new JsonNumber(Double.parseDouble(value));
}
else if (type.equalsIgnoreCase("string"))
{
return new JsonString(value);
}
else if (type.equalsIgnoreCase("date"))
{
switch (onError)
{
case Throw:
throw new InvalidJsonException("Can't use date in JSON");
case Skip:
return new JsonNull();
case Hack:
return new JsonHack("new Date(" + value + ")");
}
}
else if (type.equalsIgnoreCase("xml"))
{
switch (onError)
{
case Throw:
throw new InvalidJsonException("Can't use XML in JSON");
case Skip:
return new JsonNull();
case Hack:
return new JsonHack(EnginePrivate.xmlStringToJavascriptDom(value));
}
}
else if (type.equalsIgnoreCase("array"))
{
JsonArray array = new JsonArray();
// If the text is null then the whole bean is null
if (value.trim().equals(ProtocolConstants.INBOUND_NULL))
{
return new JsonNull();
}
if (!value.startsWith(ProtocolConstants.INBOUND_ARRAY_START))
{
throw new InvalidJsonException(Messages.getString("CollectionConverter.FormatError", ProtocolConstants.INBOUND_ARRAY_START));
}
if (!value.endsWith(ProtocolConstants.INBOUND_ARRAY_END))
{
throw new InvalidJsonException(Messages.getString("CollectionConverter.FormatError", ProtocolConstants.INBOUND_ARRAY_END));
}
value = value.substring(1, value.length() - 1);
StringTokenizer st = new StringTokenizer(value, ProtocolConstants.INBOUND_ARRAY_SEPARATOR);
int size = st.countTokens();
for (int i = 0; i < size; i++)
{
String token = st.nextToken();
String[] split = ParseUtil.splitInbound(token);
String splitValue = split[LocalUtil.INBOUND_INDEX_VALUE];
InboundVariable nested = context.getInboundVariable(splitValue);
array.add(nested.getJsonValue(onError, currentDepth + 1));
}
return array;
}
else if (type.startsWith("Object_"))
{
JsonObject object = new JsonObject();
// If the text is null then the whole bean is null
if (value.trim().equals(ProtocolConstants.INBOUND_NULL))
{
return new JsonNull();
}
if (!value.startsWith(ProtocolConstants.INBOUND_MAP_START))
{
throw new InvalidJsonException(Messages.getString("MapConverter.FormatError", ProtocolConstants.INBOUND_MAP_START));
}
if (!value.endsWith(ProtocolConstants.INBOUND_MAP_END))
{
throw new InvalidJsonException(Messages.getString("MapConverter.FormatError", ProtocolConstants.INBOUND_MAP_END));
}
value = value.substring(1, value.length() - 1);
// Loop through the property declarations
StringTokenizer st = new StringTokenizer(value, ",");
int size = st.countTokens();
for (int i = 0; i < size; i++)
{
String token = st.nextToken();
if (token.trim().length() == 0)
{
continue;
}
int colonpos = token.indexOf(ProtocolConstants.INBOUND_MAP_ENTRY);
if (colonpos == -1)
{
throw new InvalidJsonException(Messages.getString("MapConverter.MissingSeparator", ProtocolConstants.INBOUND_MAP_ENTRY, token));
}
// Convert the value part of the token by splitting it into the
// type and value (as passed in by Javascript)
String valStr = token.substring(colonpos + 1).trim();
String[] splitIv = ParseUtil.splitInbound(valStr);
String splitIvValue = splitIv[LocalUtil.INBOUND_INDEX_VALUE];
String keyStr = token.substring(0, colonpos).trim();
InboundVariable nested = context.getInboundVariable(splitIvValue);
object.put(keyStr, nested.getJsonValue(onError, currentDepth + 1));
}
return object;
}
log.warn("Data type: " + type + " is not one that InboundVariable understands");
throw new InvalidJsonException("Unknown data type");
}
/**
* Was this type null on the way in
* @return true if the javascript variable was null or undefined.
*/
public boolean isNull()
{
return type.equals(ProtocolConstants.INBOUND_NULL);
}
/**
* @return Returns the value.
*/
public String getValue()
{
return formField.getString();
}
/**
* @return Returns the file value
*/
public FormField getFormField()
{
return formField;
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString()
{
return type + ProtocolConstants.INBOUND_TYPE_SEPARATOR + formField.getString();
}
/* (non-Javadoc)
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj)
{
if (this == obj)
{
return true;
}
if (!(obj instanceof InboundVariable))
{
return false;
}
InboundVariable that = (InboundVariable) obj;
if (!this.type.equals(that.type))
{
return false;
}
if (!this.formField.equals(that.formField))
{
return false;
}
if (this.key == null || that.key == null)
{
return false;
}
return true; // this.key.equals(that.key);
}
/* (non-Javadoc)
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode()
{
return formField.hashCode() + type.hashCode();
}
/**
* How do be lookup references?
*/
private InboundContext context;
/**
* The variable name
*/
private String key;
/**
* The javascript declared variable type
*/
private String type;
/**
* The javascript declared file value
*/
private FormField formField;
/**
* The log stream
*/
private static final Log log = LogFactory.getLog(InboundVariable.class);
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy