JsonHandler.java
/*******************************************************************************
* Copyright (c) 2016 EclipseSource.
*
* Distributed under MIT license
* See https://github.com/ralfstx/minimal-json/blob/master/LICENSE
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
******************************************************************************/
package net.sourceforge.plantuml.json;
/**
* A handler for parser events. Instances of this class can be given to a
* {@link JsonParser}. The parser will then call the methods of the given
* handler while reading the input.
* <p>
* The default implementations of these methods do nothing. Subclasses may
* override only those methods they are interested in. They can use
* <code>getLocation()</code> to access the current character position of the
* parser at any point. The <code>start*</code> methods will be called while the
* location points to the first character of the parsed element. The
* <code>end*</code> methods will be called while the location points to the
* character position that directly follows the last character of the parsed
* element. Example:
* </p>
*
* <pre>
* ["lorem ipsum"]
* ^ ^
* startString endString
* </pre>
* <p>
* Subclasses that build an object representation of the parsed JSON can return
* arbitrary handler objects for JSON arrays and JSON objects in
* {@link #startArray()} and {@link #startObject()}. These handler objects will
* then be provided in all subsequent parser events for this particular array or
* object. They can be used to keep track the elements of a JSON array or
* object.
* </p>
*
* @param <A> The type of handlers used for JSON arrays
* @param <O> The type of handlers used for JSON objects
* @see JsonParser
*/
public abstract class JsonHandler<A, O> {
// ::remove folder when __HAXE__
JsonParser parser;
/**
* Returns the current parser location.
*
* @return the current parser location
*/
protected Location getLocation() {
return parser.getLocation();
}
/**
* Indicates the beginning of a <code>null</code> literal in the JSON input.
* This method will be called when reading the first character of the literal.
*/
public void startNull() {
}
/**
* Indicates the end of a <code>null</code> literal in the JSON input. This
* method will be called after reading the last character of the literal.
*/
public void endNull() {
}
/**
* Indicates the beginning of a boolean literal (<code>true</code> or
* <code>false</code>) in the JSON input. This method will be called when
* reading the first character of the literal.
*/
public void startBoolean() {
}
/**
* Indicates the end of a boolean literal (<code>true</code> or
* <code>false</code>) in the JSON input. This method will be called after
* reading the last character of the literal.
*
* @param value the parsed boolean value
*/
public void endBoolean(boolean value) {
}
/**
* Indicates the beginning of a string in the JSON input. This method will be
* called when reading the opening double quote character
* (<code>'"'</code>).
*/
public void startString() {
}
/**
* Indicates the end of a string in the JSON input. This method will be called
* after reading the closing double quote character (<code>'"'</code>).
*
* @param string the parsed string
*/
public void endString(String string) {
}
/**
* Indicates the beginning of a number in the JSON input. This method will be
* called when reading the first character of the number.
*/
public void startNumber() {
}
/**
* Indicates the end of a number in the JSON input. This method will be called
* after reading the last character of the number.
*
* @param string the parsed number string
*/
public void endNumber(String string) {
}
/**
* Indicates the beginning of an array in the JSON input. This method will be
* called when reading the opening square bracket character (<code>'['</code>).
* <p>
* This method may return an object to handle subsequent parser events for this
* array. This array handler will then be provided in all calls to
* {@link #startArrayValue(Object) startArrayValue()},
* {@link #endArrayValue(Object) endArrayValue()}, and {@link #endArray(Object)
* endArray()} for this array.
* </p>
*
* @return a handler for this array, or <code>null</code> if not needed
*/
public A startArray() {
return null;
}
/**
* Indicates the end of an array in the JSON input. This method will be called
* after reading the closing square bracket character (<code>']'</code>).
*
* @param array the array handler returned from {@link #startArray()}, or
* <code>null</code> if not provided
*/
public void endArray(A array) {
}
/**
* Indicates the beginning of an array element in the JSON input. This method
* will be called when reading the first character of the element, just before
* the call to the <code>start</code> method for the specific element type
* ({@link #startString()}, {@link #startNumber()}, etc.).
*
* @param array the array handler returned from {@link #startArray()}, or
* <code>null</code> if not provided
*/
public void startArrayValue(A array) {
}
/**
* Indicates the end of an array element in the JSON input. This method will be
* called after reading the last character of the element value, just after the
* <code>end</code> method for the specific element type (like
* {@link #endString(String) endString()}, {@link #endNumber(String)
* endNumber()}, etc.).
*
* @param array the array handler returned from {@link #startArray()}, or
* <code>null</code> if not provided
*/
public void endArrayValue(A array) {
}
/**
* Indicates the beginning of an object in the JSON input. This method will be
* called when reading the opening curly bracket character (<code>'{'</code>).
* <p>
* This method may return an object to handle subsequent parser events for this
* object. This object handler will be provided in all calls to
* {@link #startObjectName(Object) startObjectName()},
* {@link #endObjectName(Object, String) endObjectName()},
* {@link #startObjectValue(Object, String) startObjectValue()},
* {@link #endObjectValue(Object, String) endObjectValue()}, and
* {@link #endObject(Object) endObject()} for this object.
* </p>
*
* @return a handler for this object, or <code>null</code> if not needed
*/
public O startObject() {
return null;
}
/**
* Indicates the end of an object in the JSON input. This method will be called
* after reading the closing curly bracket character (<code>'}'</code>).
*
* @param object the object handler returned from {@link #startObject()}, or
* null if not provided
*/
public void endObject(O object) {
}
/**
* Indicates the beginning of the name of an object member in the JSON input.
* This method will be called when reading the opening quote character
* ('"') of the member name.
*
* @param object the object handler returned from {@link #startObject()}, or
* <code>null</code> if not provided
*/
public void startObjectName(O object) {
}
/**
* Indicates the end of an object member name in the JSON input. This method
* will be called after reading the closing quote character (<code>'"'</code>)
* of the member name.
*
* @param object the object handler returned from {@link #startObject()}, or
* null if not provided
* @param name the parsed member name
*/
public void endObjectName(O object, String name) {
}
/**
* Indicates the beginning of the name of an object member in the JSON input.
* This method will be called when reading the opening quote character
* ('"') of the member name.
*
* @param object the object handler returned from {@link #startObject()}, or
* <code>null</code> if not provided
* @param name the member name
*/
public void startObjectValue(O object, String name) {
}
/**
* Indicates the end of an object member value in the JSON input. This method
* will be called after reading the last character of the member value, just
* after the <code>end</code> method for the specific member type (like
* {@link #endString(String) endString()}, {@link #endNumber(String)
* endNumber()}, etc.).
*
* @param object the object handler returned from {@link #startObject()}, or
* null if not provided
* @param name the parsed member name
*/
public void endObjectValue(O object, String name) {
}
}