First, there is no such thing as a property mode. I know, I know, it shows up in the material, but....when you read mode, think type.

aside: there was a time when the term property mode was used, but Pega has simplified a lot and uses standard terms. The term mode still shows up in the Help file so it is used in training, but one day....

So, remember mode = type.

There are different types of properties.

The type of property defines what values that property is able to store. For example, if I define a property's type as being an integer, I can only store numerical digits in that property's value. The letters A, G, H, or Z just will not take, nor will any other non-numerical characters.

Pega organizes property types into three broad categories (these categories is where the term mode originally came from):

A property can be of a single value type. Examples of single value types are integer, a string (or, text), a date, a boolean, a decimal, etc. For example, I create a property named FirstName and I set the type to Text. I can store a single textual value in that property.

A property can be of a page type. Pages are just a collection of other properties, regardless of the type. For example, I create a property named Customer and I set the type to Single Page. The Customer page is a single page - because it represents a single customer. I would then define the other properties that make up the Customer. Those other properties could be single value properties such as FirstName and LastName, but I could also define another page type property named Address. The Address page then contains other properties, and so on.

A property can be of an advanced type. Advanced type properties are....well...advanced.

aside: the value group and value list types are in the advanced category - and those two types just seem to fascinate some people, so they keep showing up in training. Notice all you get is the definition, you don't get to use them; because they are...well...advanced :)

Now, sometimes, I need to collect more than one value for a given property - be it a single value or a page type property. For example, even though I want to collect data about a single customer, a single customer might have more than one address (for example, shipping and billing addresses).

That is where list and group come in.

Let's start with list.

A list is considered an ordered list of values. It is considered ordered because every time you add a value to a list type property, that value gets stored in a numbered index position. So, the first value stored goes in the first index position, the second value stored goes in the second index position, and so on. To store a value in a list, you do not have to specify the index position; the newest value will always be stored in next available numbered index position. A good example is the Address property for my Customer. An address is made up of multiple attributes (street, city, state, postal code, etc), so I definitely need to make the Address property a Page type. However, if I want to collect more than one address per customer (a list of addresses), I need to define the Address property as a Page List type property.

So, my Customer property is a single page, which contains a page list (for those addresses).

A value list is effectively the same thing (you can store more than one value in a numbered index), but instead of using a property type from the Page category you can only select a property type from the Single Value category. I have too much disdain for this property type to come up w/ a good example off the top of my head, so I'll come back and edit this post when I do. But, basically, a value list falls in the single value category - it is a single property that can store more than one value.

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I will edit this post with an explanation of groups in a bit.

eddie