> For the complete documentation index, see [llms.txt](https://evomimic.gitbook.io/map-book/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://evomimic.gitbook.io/map-book/dahn-human-experience-of-the-map/dahn-visualizers/property-visualizers.md).

# Property Visualizers

Copyright (c) 2022, this book is offered to the world under Creative Commons license CC BY-NC-SA 4.0

The MAP L0 Ontology provides for the definition of both ***primitive*** and ***composite*** ***property types***. Property values differ from holons in the following ways:

* property values they have no independent existence. Properties define the qualities of a holon. They have no existence independent of their holon.
* they have no unique identifier
* properties cannot participate in relationships with other holons.

DAHN provides default visualizers for each property type. The following shows simple visualizers for a *string* property type:

![](https://777163467-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Mgr-A9gty1QVUBTbFyp%2Fuploads%2FTsqvfbsFgFpxPzht1ZJl%2Fimage.png?alt=media\&token=c04ef032-0f3f-4b11-868a-900949dab589)

The figure illustrates the appearance for a *Short String Visualizer* and a *Long MD* (for [Markdown](https://en.wikipedia.org/wiki/Markdown)) *String Visualizer*. Two modes are shown for each visualizer: *read-mode* and *edit-mode*. Meta-data about the string property (e.g., min/max length, localized label, validation rules, format, etc.) are assumed to be stored in the *L0 Property Type descriptor*. The *DAHN Selector Function* could, for example, use the length and format of the string property to decide on whether to use the *Short String Visualizer* or *Long MD String Visualizer* for a given property. Additional factors could influence the selection and configuration of visualizers. For example, the actual observed length of instances of a given property could be used to calculate the visual size of the field and/or adjust font sizes used. 

The above figure also illustrates *personalization controls* (![](https://777163467-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Mgr-A9gty1QVUBTbFyp%2Fuploads%2FrxywBNh4Hos5wvUzJ9BN%2Fimage.png?alt=media\&token=65f5040c-faba-406f-a483-a3dae806d3a1)). Clicking on the control will show visualization options available for that property (e.g., the availability of alternate visualizers for this property type). Dragging the control for a property allows the display order of that property within its containing *node visualizer* to be changed as discussed above. 

As another example of a property visualizer, the visualizer for a *date* property type may display the localized label (e.g. *publication date*) and display the date value in a localized date format. In *edit mode*, the date visualizer could allow the human agent to either enter the date from the keyboard or select the desired date from a calendar pop-up.

For simple property types, the selection of a *property visualizer* is fairly straightforward. The choice gets a bit more interesting when dealing with *enumerated property types* -- i.e., property types where there is a finite list of valid values. Notice the *format* property in our previous example:

![](https://777163467-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Mgr-A9gty1QVUBTbFyp%2Fuploads%2FQ0Clpun8aoyNbuv5Oq79%2Fimage.png?alt=media\&token=cf3efdb5-64b5-4880-9747-e950ffc9756c)

The example shows a *Single-Select, Drop List visualizer* for the *format* property. However, other choices are possible:

![](https://777163467-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Mgr-A9gty1QVUBTbFyp%2Fuploads%2FHTZmqd1SSUQa9LWOCMLj%2Fimage.png?alt=media\&token=576ce151-f05b-4698-b749-26921244a8f7)

The *DAHN selector function* can be thought of as evaluating a set of rules. For example, consider the following ruleset :

```
// Selector Rules for ResourceFormat Enumerated Property Type
// Rule #1
if (count_of_possible_values <=7) 
then if (number_of_allowed_selections > 1)
        then use CheckBoxVisualizer
        else use RadioButtonVisualizer

// Rule #2
if ((count_of_possible_values > 7)
    AND(count_of_possible_values <= 20)
then if (number_of_allowed_selections > 1)
        then use DropListMultiSelectVisualizer
        else use DropListSingleSelectVisualizer

// Rule #3
if (count_of_possible_values > 20)
        AND (number_of_allowed_selections > 1)
        then use TypeAheadSearchVisualizer
```

To use this ruleset, the *selector function* retrieves the length of the list of possible values (count\_of\_possible\_values) and whether or not the agent is allowed to select multiple values (number\_of\_allowed\_selections > 1) or only a single value from the meta-information about the *ResourceFormat* property type maintained in the *L0* *MetaSpace* happ.&#x20;

In our example, the list of values for the format property type consists of 12 values, so Rule #2 applies. Assuming (per the L0 descriptor) only a single value is allowed for the format property type, the *Single-Select* form of the *Drop List* is appropriate.

In addition to meta-information maintained in the Meta-Space happ, the *DAHN selector function* may also rely on information maintained within the DAHN happ itself. This is explained in the [#dahn-is-adaptive](#dahn-is-adaptive "mention")section.

#### Initial DAHN Property Types

<mark style="color:purple;">\<list of property types... JSON too limited, Open API/Swagger, mime types, semantic web types, Bali, primitive and composite properties></mark>

**Copyright (c) 2022, this book is offered to the world under Creative Commons license** [**CC BY-NC-SA 4.0**](https://creativecommons.org/licenses/by-nc-sa/4.0/)