EmbeddedParser Class

The basic format for an embedded function inside an expression (e.g. a SQL statement) is !fnXXX[flags](params) where ALL embedded functions must start with "!fn" (case-sensitive), be followed by the function name (also case-sensitive), optionally followed by activation flags (currently only "$" is supported indicating that the result should be AnsiQuoted), followed by an open parenthesis and closing parenthesis between which a set of comma-separated parameters may optionally be specified. For example, !fnBitTest(0x00000002, 1) tests whether or not the 1st bit (0-indexed) is set (which it is in this case) and evaluates to 1 if so, else 0.

The parser includes a set of intrinsic functions:

• fnAppCacheVer - Return the application version number string. The returned format is ver=xxx, where xxx is the application version in production mode, or a timestamp otherwise.
• fnAppProperty - The value of the specified application property.
• fnBitTest - Tests for a bit being set. Evaluates to zero if not set. Format is: fnBitTest(value, bitnum) where bitnum is the 0-based index of the bit to test.
• fnCacheVer - Return a version number for managing included javascript, or style sheets. Ensures the latest versions of files using this function will be up to date and never stale.
• fnCulture - The name of the current Culture for the current user.
• fnCultureBase - The name of the current base Culture for the current user (e.g. 'en' for any English language culture).
• fnDBLookup - Looks up a value in the database. Format is: fnDBLookup(col, table, where). This provides similar functionality to the DBLookup(String, String, String) function.
• fnFormat - Format data. Format is: fnFormat(value, datatype, format) where datatype is currently limited to d=date/time and format is a standard .Net formatting string.
• fnNamedFilter - Takes a string that refers to a name of a named filter.
• fnNewGUID - Generates a new GUID. An optional format parameter may be specified.
• fnNow - The current date/time with optional timezone defaulting to user's local timezone.
• fnNowAdd - The current date/time with the specified offset in the form fnNowAdd(period [,count [,timezone]]) where period is one of y, M, d, H, m, s, or f, and defaulting to user's local timezone.
• fnNowAddUTC - The current date/time in UTC with the specified offset in the form fnNowAddUTC(period [,count]) where period is one of y, M, d, H, m, s, f.
• fnNowUTC - The current date/time in UTC.
• fnProfilesFilter - Returns the IN clause formatted string for all of the current user's profiles.
• fnProxyUserID - The Proxy ID for the current user context.
• fnTenantID - The value of Session.TenantID.
• fnTimePeriod - Takes a datetime column name and required time period keyword (e.g. today, yesterday).
• fnTimePeriodUTC - Takes a UTC datetime column name and required time period keyword (e.g. today, yesterday).
• fnToday - The current date (with 00:00:00 time component) with optional offset and timezone in the form fnToday([period [,count [,timezone]]]) where period is one of y, M, d, H, m, s, or f, and defaulting to user's local timezone.
• fnUserGUID - The GUID for the current user.
• fnUserID - The ID for the current user.
• fnUserName - The name of the current user.

In addition to these intinsic functions, the parser supports application-specific static substitution functions and dynamic functions. Functions can be registered programmatically by calling RegisterFunction(String, String, String) on the parser or by calling RegisterEmbeddedFunction(String, String, String) on the application.

Static substitution functions can be specified in meta-data via the NetQuarry studio by creating Session Properties and setting the GenEmbeddedFunc attribute on each. Dynamic functions can be configured in meta-data as well by setting up FunctionParser Components. FunctionParser components implement the IFunctionParser interface. The IFunctionParser interface allows the platform to interrogate the component in order to determine which functions it supports and to invoke those functions when encountered during embedded function resolution.