Built-in classes

Built-in classes are classes whose instances are objects belonging to primitive data types such as integers, strings, etc.

Class name	Description	lsFusion literals
INTEGER	32-bit integer	5, 23, 1000000000
LONG	64-bit integer	5l, 23L, 10000000000000L
DOUBLE	64-bit floating point number	5.0d, 2.35D
NUMERIC, NUMERIC[ , ]	Number with fixed width and precision	5.0, 2.35
BOOLEAN	Logical data type	TRUE, NULL
TBOOLEAN	Logical data type with a separate false value	TTRUE, TFALSE, NULL
DATE	Date	1982_07_13
DATETIME, DATETIME[ ]	Date and time, optionally with fractional-seconds precision (0 to 6)	1982_07_13_18:00, 1982_07_13_18:00:00
ZDATETIME, ZDATETIME[ ]	Date and time with time zone, optionally with fractional-seconds precision (0 to 6)
TIME, TIME[ ]	Time, optionally with fractional-seconds precision (0 to 6)	18:00, 18:00:00
YEAR	Year
INTERVAL[DATE], INTERVAL[DATETIME], INTERVAL[TIME], INTERVAL[ZDATETIME]	Interval — a pair of boundary values (from / to) of the corresponding date / time class
STRING, STRING[ ]	String data type with optional maximum length, case-sensitive	'text', 'text with\nbreak'
ISTRING, ISTRING[ ]	String data type with optional maximum length, case-insensitive
BPSTRING, BPSTRING[ ]	String data type with optional maximum length, case-sensitive, stored in the database as a fixed-length string
BPISTRING, BPISTRING[ ]	String data type with optional maximum length, case-insensitive, stored in the database as a fixed-length string
TEXT	String data type of arbitrary length, case-insensitive
RICHTEXT	String data type of arbitrary length with formatting, case-insensitive
HTMLTEXT	String data type of arbitrary length with HTML markup, case-insensitive
COLOR	Color	#00ccff, #AA55CC, RGB(0, 255, 0)
JSON	JSON in normalized form (key order, duplicate keys and formatting are not preserved)
JSONTEXT	JSON stored as a text string as is
XML	XML
HTML	HTML markup stored as a string
TSVECTOR	Full-text search vector
TSQUERY	Full-text search query
FILE	File of dynamic type (file content together with extension)
NAMEDFILE	File of dynamic type (file content together with name and extension)
RAWFILE, WORDFILE, IMAGEFILE, PDFFILE, VIDEOFILE, DBFFILE, EXCELFILE, CSVFILE, TEXTFILE, HTMLFILE, JSONFILE, XMLFILE, TABLEFILE	Files of specific type (RAWFILE: file with no extension or with unknown extension)
LINK	Link to a file (URI)
RAWLINK, WORDLINK, IMAGELINK, PDFLINK, VIDEOLINK, DBFLINK, EXCELLINK, CSVLINK, TEXTLINK, HTMLLINK, JSONLINK, XMLLINK, TABLELINK	Link to a file of a specific type (RAWLINK: link to a file with no extension or an unknown extension)

Inheritance

The built-in classes can be divided into seven class families (assuming that each of the remaining classes forms its own class family)

Class family	Classes
Numbers	INTEGER, LONG, DOUBLE, NUMERIC, NUMERIC[ , ], YEAR
Strings	STRING, STRING[ ], ISTRING, ISTRING[ ], BPSTRING, BPSTRING[ ], BPISTRING, BPISTRING[ ], TEXT, RICHTEXT, HTMLTEXT
Date and time	DATETIME, DATETIME[ ]
Time	TIME, TIME[ ]
Date and time with time zone	ZDATETIME, ZDATETIME[ ]
Files of a specific type	RAWFILE, WORDFILE, IMAGEFILE, PDFFILE, VIDEOFILE, DBFFILE, EXCELFILE, CSVFILE, TEXTFILE, HTMLFILE, JSONFILE, XMLFILE, TABLEFILE
Links to files of a specific type	RAWLINK, WORDLINK, IMAGELINK, PDFLINK, VIDEOLINK, DBFLINK, EXCELLINK, CSVLINK, TEXTLINK, HTMLLINK, JSONLINK, XMLLINK, TABLELINK

The built-in classes inherit only from one another within a single family, and cannot inherit from or be inherited by user classes. Inheritance within each family works on the principle that the narrower class inherits from the broader one. Where the classes of a family differ in several characteristics at once (blank padding, case insensitivity and maximum length for strings, the integer part and the precision for numbers), a class inherits from another one only when it is not wider in any of them; classes that are wider in one characteristic and narrower in another do not inherit from one another, and their common ancestor is a third class of the same family. In the DATETIME, TIME and ZDATETIME families the fractional-seconds precision is not such a characteristic: any class of such a family inherits from any other class of the same family.

A class that forms its own family is incompatible with the classes of other families and has no common ancestor with them. In particular, the HTML class (unlike HTMLTEXT, which belongs to the string family) is incompatible with the string classes: a selection with branches of the HTML and STRING classes has no common ancestor, so such a property cannot take any values, and the server reports the property '...' is always NULL error at startup. Adding (+) an HTML class value to a string is not an error, but returns a plain string: the result loses the HTML class, and the markup is escaped when displayed.

Common ancestor

According to this inheritance mechanism, the common ancestor of two built-in classes (e.g. for the selection operation) is determined as follows. If there are more than two classes, they are combined pairwise, one after another. In the rules below the two classes being combined are written in the order in which the platform combines them; that order matters only where each of the two classes inherits from the other, and in such cases the result is one of the two classes and is not determined by the pair of classes itself.

Strings

IF s1 is TEXT, RICHTEXT or HTMLTEXT
    result = s1
ELSE IF s2 is TEXT, RICHTEXT or HTMLTEXT
    result = s2
ELSE
    result = STRING[blankPadded = s1.blankPadded OR s2.blankPadded, 
                    caseInsensitive = s1.caseInsensitive OR s2.caseInsensitive, 
                    length = MAX(s1.length, s2.length)]

where blankPadded, caseInsensitive and length are in turn determined as:

Class name	blankPadded	caseInsensitive	length
STRING[n]	false	false	n
ISTRING[n]	false	true	n
BPSTRING[n]	true	false	n
BPISTRING[n]	true	true	n

A class name written without a length means unlimited length, which is greater than any n; if the resulting length is unlimited, the result is the class written without a length (STRING, ISTRING, BPSTRING, BPISTRING).

TEXT, RICHTEXT and HTMLTEXT are not blank-padded, are case-insensitive and have unlimited length, and the blank padding, case sensitivity and maximum length of the other class are not taken into account: the common ancestor of BPSTRING[10] and TEXT is TEXT, which is not blank-padded. The order of the two classes matters only when both of them are among TEXT, RICHTEXT and HTMLTEXT: these three inherit from one another in both directions, so the result is the first of the two, and such a combination should be avoided.

Numbers

IF p1.integerPart >= p2.integerPart AND p1.precision >= p2.precision
    result = p1 
ELSE IF p1.integerPart <= p2.integerPart AND p1.precision <= p2.precision
    result = p2 
ELSE IF p1.integerPart > p2.integerPart  
    result = NUMERIC[p1.integerPart+p2.precision, p2.precision]
ELSE  
    result = NUMERIC[p2.integerPart+p1.precision, p1.precision]

where integerPart and precision, in turn, are determined as:

Class name	integerPart	precision
INTEGER	10	0
YEAR	10	0
DOUBLE	99999	99999
LONG	20	0
NUMERIC[l,p]	l - p	p
NUMERIC	95	32

INTEGER and YEAR have the same integer part and precision, so each of them inherits from the other and the result is the first of the two.

In any NUMERIC class the total length (integerPart + precision) cannot exceed 127, and the precision cannot exceed 32; if the formula gives a larger total length, it is truncated to 127, which reduces the integer part of the result.

Files of a specific type

IF p1 = p2
    result = p1
ELSE
    result = RAWFILE

Links to files of a specific type

IF p1 = p2
    result = p1
ELSE
    result = RAWLINK

FILE, NAMEDFILE and LINK belong to none of these families: they are not broader classes for files and links of a specific type and have no common ancestor with them, or with each other. Two built-in classes without a common ancestor cannot be the possible results of one property — of a selection or an extremum, for example; a value of one of them is obtained from the other only by type conversion, written by the developer or applied by the platform itself, as when a file of a specific type is converted to a FILE or a NAMEDFILE and receives an extension.

Default value

It is sometimes necessary to use some value for a built-in class which will differ from NULL. Let's call this value the default value. It is used:

• with data import - in the import condition, and in the columns for which NULL values are replaced
• with form import - in the filters of the imported form
• in the automatic resolution of simple constraints
• when an object is added on a form to which filters are applied

The default value is defined as follows:

Class name	Default value
Numerical classes	0
Strings	'' (empty string)
HTML, LINK, links to files of a specific type	'' (empty string)
DATE, TIME, DATETIME, ZDATETIME	The current date / time / date and time / date and time with time zone
YEAR	The current year
Interval classes	An interval from the current moment to the current moment
BOOLEAN	TRUE (the only value of this class other than NULL)
TBOOLEAN	TTRUE
COLOR	White
JSON, JSONTEXT	{}
Files of a specific type	Empty file
FILE	Empty file with empty extension
NAMEDFILE	Empty file with empty name and extension
XML, TSVECTOR, TSQUERY	None

Extensions of specific type files

When files of a specific type (JSONFILE, XMLFILE, ...) are cast into a file of dynamic type (FILE, NAMEDFILE), whether explicitly or implicitly (e.g. with data import without specifying a format or when working with external systems), the extension of the result file is determined as follows:

Class name	Extension
RAWFILE	The empty string
JSONFILE	json
XMLFILE	xml
CSVFILE	csv
TEXTFILE	txt
WORDFILE	doc
EXCELFILE	xls
HTMLFILE	html
PDFFILE	pdf
VIDEOFILE	mp4
DBFFILE	dbf
IMAGEFILE	jpg
TABLEFILE	table

For WORDFILE, EXCELFILE and IMAGEFILE, the extension additionally depends on the content of the file:

Class name	Extension
WORDFILE	docx, if the file is in the Office Open XML format
EXCELFILE	xlsx, if the file is in the Office Open XML format
IMAGEFILE	png / bmp, if the file is in the PNG / BMP format

The content is taken into account only when the file value itself is passed on - shown to the user on a form, sent to an external system, or attached to an email message. When a file of a specific type is converted to a file of dynamic type by a property, and also when the content does not match the formats listed above, the extension from the first table is used.

Values of classes other than files of a specific type can also be cast into a file of dynamic type; in this case the extension is determined as follows:

Class name	Extension
HTML	html
XML	xml
JSON, JSONTEXT	json
Strings, LINK, links to files of a specific type	The empty string

Result properties

The platform declares one result property for each built-in class - a property without parameters that holds a value of that class. An action called from an external system passes its result to the response through them: unless the request names the properties to return, or the action has a result of its own, the response contains the value of the first property in the list below that is not NULL; the list is read from top to bottom. If the values of all these properties are NULL, the response is empty.

Class name	Property name
FILE	exportFile[]
RAWFILE	exportRawFile[]
WORDFILE	exportWordFile[]
IMAGEFILE	exportImageFile[]
PDFFILE	exportPdfFile[]
VIDEOFILE	exportVideoFile[]
DBFFILE	exportDbfFile[]
EXCELFILE	exportExcelFile[]
TEXTFILE	exportTextFile[]
CSVFILE	exportCsvFile[]
HTMLFILE	exportHtmlFile[]
JSONFILE	exportJsonFile[]
XMLFILE	exportXmlFile[]
TABLEFILE	exportTableFile[]
NAMEDFILE	exportNamedFile[]
TEXT	exportText[]
RICHTEXT	exportRichText[]
HTMLTEXT	exportHTMLText[]
STRING	exportString[]
BPSTRING	exportBpString[]
NUMERIC	exportNumeric[]
LONG	exportLong[]
INTEGER	exportInteger[]
DOUBLE	exportDouble[]
DATETIME	exportDateTime[]
ZDATETIME	exportZDateTime[]
INTERVAL[DATE]	exportIntervalDate[]
INTERVAL[DATETIME]	exportIntervalDateTime[]
INTERVAL[TIME]	exportIntervalTime[]
INTERVAL[ZDATETIME]	exportIntervalZDateTime[]
DATE	exportDate[]
TIME	exportTime[]
YEAR	exportYear[]
LINK	exportLink[]
RAWLINK	exportRawLink[]
WORDLINK	exportWordLink[]
IMAGELINK	exportImageLink[]
PDFLINK	exportPdfLink[]
VIDEOLINK	exportVideoLink[]
DBFLINK	exportDbfLink[]
EXCELLINK	exportExcelLink[]
TEXTLINK	exportTextLink[]
CSVLINK	exportCsvLink[]
HTMLLINK	exportHtmlLink[]
JSONLINK	exportJsonLink[]
XMLLINK	exportXmlLink[]
TABLELINK	exportTableLink[]
BOOLEAN	exportBoolean[]
TBOOLEAN	exportTBoolean[]
COLOR	exportColor[]
JSON	exportJSON[]
JSONTEXT	exportJSONText[]
XML	exportXML[]
User classes	exportObject[]
TSVECTOR	exportTSVectorLink[]

Language

A built-in class is written in code as a class ID - the keyword that names the class. Values of built-in classes are written as literals, each with its own form and constraints.