The document describes various functions in Ring for working with classes and objects. Some key functions covered include ispackageclass() to check if a class is in a package, classname() to get an object's class name, objectid() to get an object's ID, isobject() to check if a variable is an object, attributes() and methods() to get an object's attributes and methods, and addattribute() and addmethod() to add attributes and methods to objects.

1. Ring Documentation, Release 1.5.4
class2
class3
41.14 ispackageclass() Function
We can check if a class is defined inside package or not using the ispackageclass() function.
Syntax:
ispackageclass(cPackageName,cClassName) --> returns 1 if the Class is defined
returns 0 if the Class is not defined
Example:
see ispackageclass("package1","class1") + nl +
ispackageclass("package1","class2") + nl +
ispackageclass("package2","class1") + nl +
ispackageclass("package2","class2") + nl
Package Package1
Class class1
Func f1
Package Package2
Class class1
Func f1
Class class2
Func f1
Class class3
func f1
Output:
1
0
1
1
41.15 classname() Function
We can know the class name of an object using the classname() function
Syntax:
classname(object) --> Returns the object class name
Example:
o1 = new point
o2 = new rect
see classname(o1) + nl # print point
see classname(o2) + nl # print rect
class point
class rect
41.14. ispackageclass() Function 295

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41.16 objectid() Function
We can know the object id using the objectid() function
Syntax:
objectid(object) --> Returns the object id
Example:
o1 = new point
see objectid(o1) + nl
test(o1)
func test v
see objectid(v) + nl
Class point x y z
Output:
021B5808
021B5808
41.17 isobject() Function
We can check the variable to know if it’s an object or not using the isobject() function
Syntax:
isobject(variable) --> Returns True if it's an object, False if it's not
41.18 attributes() Function
We can get the object attributes using the attributes() function
Syntax:
attributes(object) --> Returns a list contains the object attributes
Example:
o1 = new point
aList = attributes(o1) # we can use see attributes(o1)
for t in aList see t next # print xyz
Class Point x y z
41.19 methods() Function
We can get the object methods using the methods() function
Syntax:
41.16. objectid() Function 296

3. Ring Documentation, Release 1.5.4
methods(object) --> Returns a list contains the object methods
Example:
o1 = new test
aList = methods(o1)
for x in aList
cCode = "o1."+x+"()"
eval(cCode)
next
Class Test
func f1
see "hello from f1" + nl
func f2
see "hello from f2" + nl
func f3
see "hello from f3" + nl
func f4
see "hello from f4" + nl
Output:
hello from f1
hello from f2
hello from f3
hello from f4
41.20 isattribute() Function
We can test if the object contains an attribute or not using the isattribute() function
Syntax:
isattribute(object,cAttributeName) --> Returns True if the object contains the attribute
Example:
o1 = new point
see isattribute(o1,"x") + nl # print 1
see isattribute(o1,"t") + nl # print 0
see isattribute(o1,"y") + nl # print 1
see isattribute(o1,"z") + nl # print 1
class point x y z
41.21 isprivateattribute() Function
We can test if the object contains a private attribute or not using the isprivateattribute() function
Syntax:
41.20. isattribute() Function 297

4. Ring Documentation, Release 1.5.4
isprivateattribute(object,cAttributeName) --> Returns True if the object
contains the private attribute
Example:
o1 = new person
see isprivateattribute(o1,"name") + nl +
isprivateattribute(o1,"address") + nl +
isprivateattribute(o1,"phone") + nl +
isprivateattribute(o1,"job") + nl +
isprivateattribute(o1,"salary")
Class Person
name address phone
private
job salary
Output:
0
0
0
1
1
41.22 ismethod() Function
We can test if the object class contains a method or not using the ismethod() function
Syntax:
ismethod(object,cMethodName) --> Returns True if the object class contains the method
Example:
o1 = new point
see ismethod(o1,"print") + nl # print 1
mylist = []
mylist + new point
see ismethod(mylist[1],"print") + nl # print 1
class point x y z
func print
see x + nl + y + nl + z + nl
41.23 isprivatemethod() Function
We can test if the object class contains a private method or not using the isprivatemethod() function
Syntax:
41.22. ismethod() Function 298

5. Ring Documentation, Release 1.5.4
isprivatemethod(object,cMethodName) --> Returns True if the object class contains
the private method
Example:
o1 = new Test
see isprivatemethod(o1,"f1") + nl +
isprivatemethod(o1,"f2")
Class Test
func f1
see "message from f1()" + nl
private
func f2
see "message from f2()" + nl
Output:
0
1
41.24 addattribute() Function
We can add an attribute (or a group of attributes) to the object state (not the class) using the addattribute() function
Syntax:
AddAttribute(object,cAttributeName|aAttributesList)
Example(1):
see new point {x=10 y=20 z=30}
Class Point
AddAttribute(self,["x","y","z"])
Example(2):
o1 = new point
addattribute(o1,"x")
addattribute(o1,"y")
addattribute(o1,"z")
see o1 {x=10 y=20 z=30}
class point
Output:
x: 10.000000
y: 20.000000
z: 30.000000
41.25 addmethod() Function
We can add a method to the object class using the addmethod() function This method can be used with any object from
the same class.
41.24. addattribute() Function 299

6. Ring Documentation, Release 1.5.4
Syntax:
AddMethod(Object,cNewMethodName,cMethodName|AnonymousFunction)
Example:
o1 = new point { x=10 y=20 z=30 }
addmethod(o1,"print", func { see x + nl + y + nl + z + nl } )
o1.print()
Class point
x y z
Output:
10
20
30
Instead of using anonymous function to add new method to the class, we can use the function name
Example:
o1 = new point { x=10 y=20 z=30 }
myfunc = func { see x + nl + y + nl + z + nl }
addmethod(o1,"print", myfunc )
addmethod(o1,"display", myfunc )
addmethod(o1,"show", myfunc )
o1.print()
o1.display()
o1.show()
Class point
x y z
Output:
10
20
30
10
20
30
10
20
30
Since we add the method to the class, any object from that class can use this method
Example:
o1 = new point { x=10 y=20 z=30 }
o2 = new point { x=100 y=200 z=300 }
o3 = new point { x=50 y=150 z=250 }
addmethod(o1,"print", func { see x + nl + y + nl + z + nl } )
41.25. addmethod() Function 300

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o1.print()
o2.print()
o3.print()
Class point
x y z
Output:
10
20
30
100
200
300
50
150
250
41.26 getattribute() function
We can get the object attribute value using the getattribute() function
Syntax:
GetAttribute(oObject,cAttributeName) ---> Attribute Value
Example:
o1 = new point
see getattribute(o1,"name") + nl +
getattribute(o1,"x") + nl +
getattribute(o1,"y") + nl +
getattribute(o1,"z") + nl
Class Point
x=10 y=20 z=30
name = "3D-Point"
Output:
3D-Point
10
20
30
Example:
We can Find a Class List Member using GetAttribute() using a function findclass() The Find uses the member name,
rather than the column number
myList =
[new Company {position=3 name="Mahmoud" symbol="MHD"},
new Company {position=2 name="Bert" symbol="BRT"},
new Company {position=1 name="Ring" symbol="RNG"}
]
41.26. getattribute() function 301

8. Ring Documentation, Release 1.5.4
see myList
see nl +"=====================" + nl + nl
for i = 1 to len(myList)
see "Pos: "+ i +" | "+ myList[i].position +" | "+ myList[i].name +
" | "+ myList[i].symbol +" | "+ nl
next
See findclass(myList, "MHD", "symbol") +nl ### Specify Member class name
###---------------------------------------
func findclass classList, cValue, classMember
See nl + "FindClass: " +" "+ cValue + nl + nl
for i = 1 to len(classList)
result = getattribute( classList[i], classMember )
See "Result-Attr: " + i +" "+ result +nl
if result = cValue
j = i
ok
next
return j
###--------------------------------------
class company position name symbol
Output:
Pos: 1 | 3 | Mahmoud | MHD |
Pos: 2 | 2 | Bert | BRT |
Pos: 3 | 1 | Ring | RNG |
FindClass: MHD
Result-Attr: 1 MHD
Result-Attr: 2 BRT
Result-Attr: 3 RNG
1
41.27 setattribute() function
We can set the object attribute value using the setattribute() function
Syntax:
SetAttribute(oObject,cAttributeName,Value)
Example:
o1 = new person
setattribute(o1,"cName","Mahmoud")
41.27. setattribute() function 302

9. Ring Documentation, Release 1.5.4
setattribute(o1,"nSalary",1000000)
setattribute(o1,"aColors",["white","blue","yellow"])
see o1
see o1.aColors
Class Person
cName
nSalary
aColors
Output:
cname: Mahmoud
nsalary: 1000000.000000
acolors: List...
white
blue
yellow
41.28 mergemethods() Function
We can share methods between classes without inheritance using the MergeMethods() function
This function merge class methods to another class.
Syntax:
MergeMethods(cClassNameDestination,cClassNameSource)
Example:
mergemethods("count","share")
mergemethods("count2","share")
o1 = new count { test() }
o1 = new count2 { test() }
Class Share
func one
see "one" + nl
func two
see "two" + nl
func three
see "three" + nl
Class Display
Func printline
see copy("*",20) + nl
Class Count from Display
Func test
printline()
one()
two()
three()
printline()
41.28. mergemethods() Function 303

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Class Count2 from Display
Func test
three()
two()
one()
printline()
Output:
********************
one
two
three
********************
three
two
one
********************
41.29 packagename() Function
We can know the package name of the latest sucessful import command using the packagename() function
Syntax:
packagename() --> Returns the package name of the latest sucessful import
Example:
load "weblib.ring"
import System.web
see packagename() # system.web
41.29. packagename() Function 304