org.itsnat.core.script

Interface ScriptUtil

public interface ScriptUtil

Utility interface to generate JavaScript code mainly to locate client nodes from server DOM nodes.

ItsNat provides two default implementations of this interface, these implementations are got calling ItsNatDocument.getScriptUtil() or ClientDocument.getScriptUtil()

If this utility object was got calling the method ItsNatDocument.getScriptUtil() the generated JavaScript code must be sent to the client calling ItsNatDocument.addCodeToSend(Object), this JavaScript code will be received by all clients (owner and attached) of this document.

If this utility object was got calling the method ClientDocument.getScriptUtil() the generated JavaScript code must be sent to the client calling ClientDocument.addCodeToSend(Object) this JavaScript code will be received by the specified client (use ever the same client for generating and sending code).

When a DOM node is used a parameter this node must be part of the document tree (server and client) otherwise an exception is thrown, and the generated code must be sent as soon as possible to the client/s calling the appropriated method as explained before. *

ItsNat generates JavaScript code referencing the specified node in client, when this utility object was got calling ItsNatDocument.getScriptUtil() this reference is valid for all clients of the document (in spite of internal node caching ItsNat ensures the same internal caching id is used for all clients or no caching is used).

Author:

Jose Maria Arranz Santamaria

Method Summary

Methods

Modifier and Type	Method and Description
ScriptExpr	createScriptExpr(Object value) Creates a new script expression object wrapping the specified object.
String	encodeURIComponent(char c) Is a Java implementation of the JavaScript encodeURIComponent function applied to a Java char.
String	encodeURIComponent(String text) Is a Java implementation of the JavaScript encodeURIComponent function.
String	getCallMethodCode(Object obj, String methodName, Object[] params) Generates the appropriated code to call the specified object method at the client.
String	getCallMethodCode(Object obj, String methodName, Object[] params, boolean endSentence) Generates the appropriated code to call the specified object method at the client.
String	getGetPropertyCode(Object obj, String propName) Generates the JavaScript code to get the value of the specified property.
String	getGetPropertyCode(Object obj, String propName, boolean endSentence) Generates the JavaScript code to get the value of the specified property.
String	getNodeReference(Node node) Generates the appropriated code to locate the specified DOM node at the client.
String	getSetPropertyCode(Object obj, String propName, Object value) Generates the JavaScript code to set a value to the specified property.
String	getSetPropertyCode(Object obj, String propName, Object value, boolean endSentence) Generates the JavaScript code to set a value to the specified property.
String	getTransportableCharLiteral(char c) Converts the specified Java String to a JavaScript string literal, this string can be sent to the client.
String	getTransportableStringLiteral(String text) Converts the specified Java String to a JavaScript string literal, this string can be sent to the client.
String	toScript(Object value) Converts the specified object value to JavaScript code.

Method Detail

getNodeReference

String getNodeReference(Node node)

Generates the appropriated code to locate the specified DOM node at the client.

Returned code may be considered as a JavaScript reference to the specified node.

The following example generates JavaScript to set 'City' to the "value" property of the specified DOM element aNode:

  ItsNatDocument itsNatDoc = ...;
  Element aNode = ...;
  String code = itsNatDoc.getScriptUtil().getNodeReference(aNode) + ".value = 'City';";
  itsNatDoc.addCodeToSend(code);
 

Parameters:

node - the node to generate a JavaScript reference.

Returns:

the JavaScript reference to send to the client.

createScriptExpr

ScriptExpr createScriptExpr(Object value)

Creates a new script expression object wrapping the specified object.

Returns:

a new script expression object.

getCallMethodCode

String getCallMethodCode(Object obj,
                       String methodName,
                       Object[] params,
                       boolean endSentence)

Generates the appropriated code to call the specified object method at the client.

Parameters:

obj - the object reference, converted to JavaScript calling toScript(Object).

methodName - method name.

params - the parameter list. Are converted to JavaScript calling toScript(Object).

endSentence - if true adds a ; at the end.

Returns:

the JavaScript code.

getCallMethodCode

String getCallMethodCode(Object obj,
                       String methodName,
                       Object[] params)

Generates the appropriated code to call the specified object method at the client.

Parameters:

obj - the object reference, converted to JavaScript calling toScript(Object).

methodName - method name.

params - the parameter list. Are converted to JavaScript calling toScript(Object).

Returns:

the JavaScript code.

getSetPropertyCode

String getSetPropertyCode(Object obj,
                        String propName,
                        Object value,
                        boolean endSentence)

Generates the JavaScript code to set a value to the specified property.

Parameters:

obj - the object reference, converted to JavaScript calling toScript(Object).

propName - property name.

value - the value to set. Is converted to JavaScript calling toScript(Object).

endSentence - if true adds a ; at the end.

Returns:

the JavaScript code.

getSetPropertyCode

String getSetPropertyCode(Object obj,
                        String propName,
                        Object value)

Generates the JavaScript code to set a value to the specified property.

Parameters:

obj - the object reference, converted to JavaScript calling toScript(Object).

propName - property name.

value - the value to set. Is converted to JavaScript calling toScript(Object).

Returns:

the JavaScript code.

getGetPropertyCode

String getGetPropertyCode(Object obj,
                        String propName,
                        boolean endSentence)

Generates the JavaScript code to get the value of the specified property.

Parameters:

obj - the object reference, converted to JavaScript calling toScript(Object).

propName - property name.

endSentence - if true adds a ; at the end.

Returns:

the JavaScript code.

getGetPropertyCode

String getGetPropertyCode(Object obj,
                        String propName)

Generates the JavaScript code to get the value of the specified property.

Parameters:

obj - the object reference, converted to JavaScript calling toScript(Object).

propName - property name.

Returns:

the JavaScript code.

getTransportableStringLiteral

String getTransportableStringLiteral(String text)

Converts the specified Java String to a JavaScript string literal, this string can be sent to the client.

Any special character like end of lines, tabs, " , ' , \ etc are escaped to sent to the client as a JavaScript string literal.

Parameters:

text - the String to convert.

Returns:

the resulting JavaScript string literal.

getTransportableCharLiteral

String getTransportableCharLiteral(char c)

Converts the specified Java String to a JavaScript string literal, this string can be sent to the client.

Any special character like end of lines, tabs, " , ' , \ etc are escaped to sent to the client as a JavaScript string literal.

Parameters:

c - the Java char to convert.

Returns:

the resulting JavaScript string literal.

encodeURIComponent

String encodeURIComponent(String text)

Is a Java implementation of the JavaScript encodeURIComponent function. The string encoded with this method can be unencoded using the JavaScript decodeURIComponent function.

This method is an alternative (slower and bigger) to getTransportableStringLiteral(String) to transport texts to the client.

The encoded Java String is not a string literal. The following example encloses the String as a literal:

String code = "\"" + encodeURIComponent(someText) + "\"";

Parameters:

text - the Java String to encode.

Returns:

the encoded text.

encodeURIComponent

String encodeURIComponent(char c)

Is a Java implementation of the JavaScript encodeURIComponent function applied to a Java char.

This method is an alternative (slower and bigger) to getTransportableCharLiteral(char) to transport characters to the client.

The encoded Java char is not a char literal. The following example encloses the char as a literal:

String code = "'" + encodeURIComponent(someChar) + "'";

Parameters:

c - the Java char to encode.

Returns:

the encoded char.

toScript

String toScript(Object value)

Converts the specified object value to JavaScript code.

Conversion rules if value is a:

• DOM Node: conversion is done calling getNodeReference(org.w3c.dom.Node).
• Boolean: calling value.toString() (returns the literals true and false.
• Character: calling getTransportableCharLiteral(char).
• Number: calling value.toString().
• ScriptExpr: calling ScriptExpr.getCode().
• String: calling getTransportableStringLiteral(String).
• Other: calling value.toString().

Parameters:

value - the object to convert to JavaScript.

Returns:

the JavaScript code.