com.techempower.data.util.CompositeReflectiveColumn Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of gemini Show documentation
Show all versions of gemini Show documentation
Gemini is a web framework created by TechEmpower.
/*******************************************************************************
* Copyright (c) 2018, TechEmpower, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name TechEmpower, Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL TECHEMPOWER, INC. BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*******************************************************************************/
package com.techempower.data.util;
import java.lang.reflect.*;
import java.util.*;
import com.techempower.helper.*;
/**
* Similar to ReflectiveColumn, except that this Composite version allows a
* macro to be created, resulting in multiple method calls to the provided
* object.
*/
public class CompositeReflectiveColumn
implements TabularColumn
{
//
// Constants.
//
private static final Class[] ARGUMENT_TYPES = new Class[0];
private static final Object[] ARGUMENTS = new Object[0];
//
// Member variables.
//
private final String[] methodNames;
private final String[] methodFinds;
private final String[] defaultValues;
private final String columnHeader;
private final Method[] methods;
private boolean initialized = false;
private String template;
//
// Member methods.
//
/**
* Standard Constructor.
*
* @param methodNames an array of methods to call to retrieve values.
* @param columnName the display name of the column.
* @param defaultValues an array of default values, in the same order as
* the method names.
* @param template a String representing how to render the gathered values.
* Values gathered from methods replace method names surrounded by
* { and }. For example: "{getLastname}, {getFirstname}"
*/
public CompositeReflectiveColumn(String[] methodNames, String columnName,
String defaultValues[], String template)
{
this.methodNames = methodNames.clone();
this.methods = new Method[this.methodNames.length];
this.methodFinds = new String[this.methodNames.length];
this.columnHeader = columnName;
this.defaultValues = defaultValues.clone();
this.template = template;
// Surround method names with { and } symbols so that we can quickly
// find and replace them in the template.
for (int i = 0; i < this.methodFinds.length; i++)
{
this.methodFinds[i] = "{" + this.methodNames[i] + "}";
}
}
/**
* Constructor that identifies method names and defaults by extracting
* them from the template. That is, "{getLastname}, {getFirstname}"
* ascertains that the two methods, getLastname() and getFirstname() are
* being called. Default values can be provided by following the method
* name with a colon. For example: "{getLastname:Unknown}".
*/
public CompositeReflectiveColumn(String columnHeader, String template)
{
List newMethodNames = new ArrayList<>();
List newDefaultValues = new ArrayList<>();
List newMethodFinds = new ArrayList<>();
if (StringHelper.isNonEmpty(template))
{
int pos = -1, endPos;
do
{
pos = template.indexOf('{', pos + 1);
if (pos >= 0)
{
endPos = template.indexOf('}', pos);
String extract = template.substring(pos + 1, endPos);
newMethodFinds.add("{" + extract + "}");
if (extract.indexOf(':') >= 0)
{
String[] split = extract.split(":");
newMethodNames.add(split[0]);
newDefaultValues.add(split[1]);
}
else
{
newMethodNames.add(extract);
newDefaultValues.add("");
}
}
}
while ( (pos >= 0)
&& (pos < template.length())
);
}
this.methodNames = CollectionHelper.toStringArray(newMethodNames);
this.methods = new Method[this.methodNames.length];
this.methodFinds = CollectionHelper.toStringArray(newMethodFinds);
this.columnHeader = columnHeader;
this.defaultValues = CollectionHelper.toStringArray(newDefaultValues);
this.template = template;
}
/**
* Gets the optional template to use for rendering values within the
* get(Object) method.
*
* @return the template
*/
public String getTemplate()
{
return this.template;
}
/**
* Sets an optional string template to use for rendering values within the
* get(Object) method. If specified, the template will be populated with
* the object's value where-ever the marker "$V" is found. E.g.,
*
* foo.setTemplate("/edit?id=$V");
*
*
* @param template the template to set
*/
public void setTemplate(String template)
{
this.template = template;
}
/**
* Gets the column's value for a provided object.
*/
@Override
public String getValue(Object object)
{
String[] values = getRawValues(object);
return StringHelper.replaceSubstrings(this.template, this.methodFinds, values);
}
/**
* Gets the raw values for a provided object. Note that Strings are
* escaped for rendering as HTML as they are gathered from the source
* object; it is not necessary to re-escape the resulting rendering.
*/
public String[] getRawValues(Object object)
{
if (!this.initialized)
{
this.initialized = true;
int i = 0;
try
{
for (i = 0; i < this.methodNames.length; i++)
{
this.methods[i] = object.getClass().getMethod(this.methodNames[i], ARGUMENT_TYPES);
}
}
catch (NoSuchMethodException exc)
{
throw new IllegalArgumentException("Could not find method " + this.methodNames[i], exc);
}
}
String[] values = new String[this.methods.length];
for (int i = 0; i < values.length; i++)
{
if (this.methods[i] != null)
{
try
{
Object objValue = this.methods[i].invoke(object, ARGUMENTS);
// Render the value accordingly.
if (objValue instanceof String)
{
final String string = (String)objValue;
if (StringHelper.isNonEmpty(string))
{
values[i] = NetworkHelper.render(string);
}
}
else if (objValue instanceof Integer || objValue instanceof Long)
{
values[i] = String.valueOf(objValue);
}
}
catch (InvocationTargetException | IllegalAccessException exc)
{
// Do nothing. Default will be used.
}
}
if (values[i] == null)
{
values[i] = this.defaultValues[i];
}
}
return values;
}
/**
* Gets the header for this column.
*/
@Override
public String getDisplayName()
{
return this.columnHeader;
}
} // End CompositeReflectiveColumn.