Fallen London Wiki:Semantic Mediawiki/Semantic Properties
The most common type of property is a relationship between pages. For example, an Action may be played from a Card or Storylet, which is located in a Place. And that action may have a challenge against a quality, and result in gaining an item on success. These relationships have been defined as Properties in Semantic MediaWiki, and can be embedded into existing links on the Wiki.
Properties can be "strung together" into a Property Chain. For example, Property:From Card/Storylet can connect an Action to the Storylet where it is played from; and Property:Located in can connect that Storylet to its Place. The property chain [[From Card/Storylet.Located in]] will connect the Action to the Place, even though there is no direct connection.
Links and Properties
Let's start by looking at a page on the Fallen London wiki. I'm going to pick a common and well-established action that is slightly above-average in complexity: Boast wildly, an option on a card with unlock conditions, a luck challenge, and success and failure results that modify a handful of items and qualities.
The Wiki structure of this page has links to a variety of other articles, such as the card it appears on, the unlock conditions, and results of success or failure. Several of those links share a target page, as is common. Most of these links are mediated by Templates. A version of Boast wildly is shown below highlighting a representative sample of those links.
The key idea of Semantic MediaWiki is that these links are structure, and that structure is useful. Many of these links indicate a relationship between Boast wildly and the page being linked to. Below is the same link structure, but links are now annotated with the relationship they represent.
Semantic MediaWiki lets links be annotated with the name of the relationship they represent, called "Properties." (Some of the ones in this example have been implemented on the Wiki yet, and some have not.) These relationships can then be queried, so e.g. a query for pages that gain Confident Smiles could be constructed, and embedded on the page for Confident Smiles (the Fallen London wiki currently achieves similar effect via Categories).
One way of thinking about annotated links is that they crate a structure called a Property Graph. The links from the example above could form part of the property graph shown below:
A simple query just asks for the links of a particular type going into a node, e.g. the set of pages that Gain Confident Smiles. More complicated queries can make more interesting use of the graph structure, such as using categories instead of single nodes, or chaining multiple properties in a row.
In practice, I expect that most Properties will be set on Action pages pointing to Items & Qualities, and most queries will be on those Item & Quality pages. Other common uses would be relationships between Actions and Cards/Storylets, or wearable items and their bonuses.