Learn how to create dynamic objects that you can add methods and variables too on the fly

1. Dynamic Objects

2. Overview
Objective
Learn how to create dynamic objects that you can add
methods and variables too on the fly.
Requirements
 Understanding of PVCollections
 Understanding of Closures/Anonymous Functions
Estimated Time
10 minutes
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3. Follow Along With A Code
Example
1. Download a copy of the example code at
www.prodigyview.com/source.
2. Install the system in an environment you feel
comfortable testing in.
3. Proceed to examples/design/Objects.php

4. The Object
In ProdigyView, PVObject and PVStaticObject are very
powerful classes.
 Have the design patterns to improve development
 Enable Object Oriented Programming
 Enable Aspect Oriented Programming
 Easily mutable code
Before we get into the higher level constructs, lets start
with understanding PVObjects and PVStaticObjects.

5. Create Our Class
We can start learning about how to use an object by
creating an empty class. Yes, just merely define a class
with nothing in it.
Extend PVObject or PVStaticObject
Take notice it’s empty, no methods or variables

6. Anonymous
functions/closures
Next step is to create our anonymous functions . These
functions are eventually going to become the class’s
methods.

7. Adding the Methods
We have a class with no methods and we have two
anonymous functions. Ok we are ready to go. Because
our class extends PVObject, we have access to a method
called addMethod(). This method will allow us to add our
anonymous functions as methods that become part of the
class.
Add our anonymous function
Set the name of the method

8. Calling the Methods
Ok so we’ve added the methods to our object that was
once empty. Now we can call those methods by using the
-> operator and the name we assigned the method.
Name of the method
Remember, the anonymous function $write_email accepted two parameters.

9. PVCollection
If you remember PVCollection, we could add information
and retrieve information from it at any time.
Every class that extends PVObject and PVStaticObject
has a PVCollection built in. This makes it possible to add
data to an object and also iterate through the objects
data.
Let’s take a look on the next slide.

10. Adding Variables
When we created our class, it was empty with no
variables. Let’s change that by adding some variables.
The method addToCollectionWithName is a method
inherited from PVObject and will allow us to add variables
to the objects collection that can be retrieved later. Or you
can explicitly add a variable by assigning it using the ‘->’
operator.
Name of the variable Value associated with the name
Name of the variable Value associated with the variable

11. Get the variables
Like the methods, we can now get the variables that were
assigned to our once empty object. Also we can iterate
through the variables that were added.
Get the variables by calling the name assigned to them

12. PVObjects
Pretty cool? Well this is only the tip of the ice berg.
With a clear understanding of adding methods and
variables to an object, we have the ability to create very
dynamic objects.
Once combined with design patterns, you will able to
leverage aspect oriented programming and other
capabilities that will make building an application
incredibly easy and robust.

13. Challenge!
To better understand the concepts covered, complete the
optional challenge below.
1. Start out with an empty class.
2. Add a variable to the class
3. Add a function to this call that will retrieve the variable
and pass it to another function that alters the result.
4. Then pass the altered result back to where the
function was originally called.

14. The Not So Obvious
1. Adding a variable to an object can also be accomplish
by using the method addToCollection. But the variable
will not be assigned a key for accessing it later. The
variable can retrieved when using the getIterator()
method.
2. All objects have a PVCollection. All variables are
assigned and pulled from this collection behind the
scenes.

15. Review
 To create dynamic objects, make sure the class
extends PVObject or PVStaticObject
 Closures/anonymous functions can be added to using
the addMethod function
 Variables can be added using the
addCollectionWithName() method or explicitly
applying the variable with ‘->’ operator.

16. API Reference
For a better understanding of the Collections and the
Iterator, check out the api at the two links below.
PVStaticObject
PVObject
More Tutorials
For more tutorials, please visit:
http://www.prodigyview.com/tutorials
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