<@interface name="KitHelpers" alias="$ENV">
Extension point for defining kit helper objects
(c) SAP AG 2003-2006. All rights reserved.
+
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# The name of the helper class
* # An argument to pass to the helper class constructor.
See further explanations about ARGS in
XML definition of channel: @env:KitChannels!defineChannel
Example
com.sap.vctests:HelperClass
{id: "someid"}
function defineHelper(className, p1, p2, p3, p4, p5, p6, p7) {
// case of helper anonymous object
if (arguments.length == 2 && typeof arguments[0] == 'object' && typeof arguments[1] == 'string') {
var name=arguments[1], obj=arguments[0];
if (!isValidId(name)) return raiseKitError('Invalid namespace specification of helper object name:'+ name + " in kit :" + _currentPackage);
if (name in _kitHelpers) return raiseKitError('Helper object "'+name+'" is already defined');
_kitHelpers[UPPER(name)] = obj;
return obj;
}
// case of helper function
if (arguments.length == 2 && typeof arguments[0] == 'string' && typeof arguments[1] == 'function') {
var name=arguments[0], func=arguments[1];
if (!isValidId(name)) return raiseKitError('Invalid namespace specification of helper function name:'+ name + " in kit :" + _currentPackage);
if (name in _kitHelpers) return raiseKitError('Helper function "'+name+'" is already defined');
try {
eval('func = '+func);
} catch(e) {
return raiseKitError('Syntax error in helper function "'+name+'": '+e.description);
}
_kitHelpers[UPPER(name)] = func;
return func;
}
// case of helper object
var obj = $ENV.createObject(className, p1, p2, p3, p4, p5, p6, p7);
if (!obj) return raiseKitError('Invalid helper "'+className+'" definition' );
#DEVTIME[
if (!ISA(obj , 'core.gml:Object') ) return raiseKitError(className +' is not sub class of Object');
]
var id = UPPER(obj.id);
if (!isValidId(obj.id)) return raiseKitError('Invalid namespace specification of helper object Id:'+ obj.id + " in kit :" + _currentPackage);
if (!id) return raiseKitError('Id is missing from helper "'+className+'" definition');
if (id in _kitHelpers) raiseKitError('Helper object "'+id+'" is already defined');
_kitHelpers[id] = obj
return obj;
}
<@method name="getHelper">
Returns a specified helper object/function
The Id of the helper object/function to get
The requested helper object/function
function getHelper(id) {
return _kitHelpers[UPPER(id)] || null;
}
<@method name="getHelpersTable">
Returns the complete helpers table
Table of helpers objects, indexed by their identifiers
Helper id's are stored in uppercase. Use @lib:Basic!UPPER macro to convert the helper id to uppercase
before using it as the index in this table.
function getHelpersTable() {
return _kitHelpers;
}
<@method name="parseHelper" scope="private">
Parses the given helper node and returns a string which represents its details
channel node to parse
Helper functions are not supported by this method
function parseHelper(helperNode) {
var map = getNodeProps(helperNode);
var classname = map['classname'];
if (!classname) return "";
var args = getNodeArgs(helperNode);
var res = "$ENV.defineHelper(" + STR(classname) + "," + JOIN(args,",") + ");";
return res;
}
<@method name="removeHelper">
Removes a specified helper object/function
The Id of the helper object/function to remove
function removeHelper(id) {
delete _kitHelpers[UPPER(id)];
}
<@method name="executeHelper">
Executes a specified helper function
The Id of the helper function to execute
A variable list of arguments to pass to the helper function
The helper function result
function executeHelper(id, p1, p2, p3, p4, p5, p6, p7) {
try {
var fn = _kitHelpers[UPPER(id)] || null;
return fn ? fn(p1, p2, p3, p4, p5, p6, p7) : undefined;
} catch(e) {
raiseKitError('Failed to execute helper function "'+id+'": '+e.description);
return undefined;
}
}