====ARDI Selectors====

**Selectors** are a new method of searching for and choosing ARDI assets.

They're smaller, simpler and faster to write than AQL statements, although slightly less flexible. Selectors are often used when choosing/specifying assets. They will be appearing in more ARDI plugins as time goes on, and can also be used in queries AQL using the **SELECTPOINTS** and **SELECTASSETS** functions.

They are loosely inspired by //CSS Selectors//, which are used in web-pages to help select the various components of a web page. 

===What A Selector Does===

A selector is a type of search - it hunts through your ARDI assets to find any that match the criteria you've written in your selector.

These can be used whenever you need to quickly address a number of assets at once - such as when attaching alerts, in security rules or when creating charts and visualisations.

Selectors are usually used in one of two ways - to **find** an asset (or assets) in your ARDI database, or to **validate** an asset to see if it matches some type of search criteria.

===Selector Syntax===

A selector is made up of //rules// which are combined together to search for specific assets. Most rules have a symbol at the start to control what you're searching for.

===Asset Name Rules===

A rule with no symbol at all is an **asset name rule** - it searches ARDI for any assets with that name, ID or data value.

The selector...

   Finish Oven

...would find any assets named 'Finish Oven'.

===Asset Type Rules===

A rule with the '@' symbol at the start is an **asset type rule** - it searches ARDI for all assets of a particular type.

The selector...

   @Temperature Sensor

...would find all assets with a type (or that are a sub-type) of 'Temperature Sensor'.

===Property Name Rules===

A rule with a period (.) at the start is a **property name rule** - it searches ARD for all assets that have a particular property.

The selector...

    .Internal Temperature

...will search for all assets that have the 'Internal Temperature' or 'Temperature - Internal' property.

===Quotes and Escaping===

If you need to search for an asset or property that contains reserved characters (ie, the '.' or ':' characters), you can enclose the name in quotes.

For example, "PMP.1223" will search for an asset named with a reference number/name of **PMP.1223** instead of an **asset** named PMP with a property called **1223**.

===Using Relationships===

You can also [[related|use relationships in your selectors]].