Glossary

Rule Syntax for Config Files

The various Nomad Media config files use a SQL-based rule parser for enabling and disabling processors, profiles, and other configuration aspects.

General Syntax

Rules are valid SQL statements written against asset properties. For example:

ImageHeight >= 500

Compound statements using AND, OR, and NOT:

ImageHeight >= 500 AND ContentLength = 66992

Use parentheses to force precedence:

ImageHeight >= 1200 AND (ContentType LIKE '%jpeg' OR ContentType LIKE '%jpg')

Available Asset Properties

Rules can reference any of the following properties (plus custom metadata properties):

Property	Example Value
`bucketType`	`3`
`assetType`	`2`
`assetTypeDisplay`	`"File"`
`storageEventName`	`"ObjectCreated:Put"`
`originalObjectKey`	`"Content/Public/Media/image.jpg"`
`contentLength`	`66992`
`contentType`	`"image/jpeg"`
`mediaType`	`1`
`mediaTypeDisplay`	`"Image"`
`imageHeight`	`500`
`imageWidth`	`800`
`audioTrackCount`	`0`
`hasAudio`	`false`
`storageClass`	`1`
`createdDate`	`"2022-08-26T08:41:51.541Z"`

C# Example

string rule = "url LIKE '%content/wsls/2022/09/06/noon 1 hour 9.6.22/%'";
CaseInsensitiveDictionary<object> properties = new CaseInsensitiveDictionary<object>();
properties.SetValue("url", "nomad-dev-04-system-content-rc46y2f3ixyo::Content/WSLS/2022/09/06/Noon 1 HOUR 9.6.22/AM NATIONAL SUICIDE PRE_WSLS5QWD.mxf");

bool ruleValue = SqlRuleParserRepository.Value.ProcessRule(rule, properties, null);
Assert.True(ruleValue);

SQL Syntax Reference

Comparison Operators

Operator	Description
`<`	Less than
`>`	Greater than
`<=`	Less than or equal
`>=`	Greater than or equal
`<>`	Not equal
`=`	Equal
`IN`	Value in list
`LIKE`	Pattern match

Arithmetic Operators

Operator	Description
`+`	Addition
`-`	Subtraction
`*`	Multiplication
`/`	Division
`%`	Modulus

Boolean Operators

AND, OR, NOT. AND has precedence over OR. Use parentheses to override:

(LastName = 'Smith' OR LastName = 'Jones') AND FirstName = 'John'

Wildcard Characters

Both * and % can be used interchangeably as wildcards in a LIKE comparison. Wildcards are allowed at the start, end, or both ends of a pattern — but not in the middle:

"ItemName LIKE '*product*'"
"ItemName LIKE '*product'"
"ItemName LIKE 'product*'"

Note: 'te*xt' is not allowed (wildcard in the middle).

Aggregate Functions

Function	Description
`Sum(expr)`	Sum
`Avg(expr)`	Average
`Min(expr)`	Minimum
`Max(expr)`	Maximum
`Count(expr)`	Count
`StDev(expr)`	Statistical standard deviation
`Var(expr)`	Statistical variance

Example:

Sum(Price)
Avg(Child.Price)

Built-in Functions

Function	Syntax	Description
`CONVERT`	`Convert(expression, type)`	Converts to a .NET type (e.g. `Convert(total, 'System.Int32')`)
`LEN`	`LEN(expression)`	Returns the length of a string
`ISNULL`	`ISNULL(expression, replacementvalue)`	Returns replacement if expression is null
`IIF`	`IIF(expr, truepart, falsepart)`	Conditional — returns truepart or falsepart
`TRIM`	`TRIM(expression)`	Removes leading/trailing whitespace (`\r`, `\n`, `\t`, space)
`SUBSTRING`	`SUBSTRING(expression, start, length)`	Returns a substring

Examples:

Convert(total, 'System.Int32')
Len(ItemName)
IsNull(price, -1)
IIF(total>1000, 'expensive', 'cheap')
SUBSTRING(phone, 7, 8)