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4GL/JSON conversion rules

Certain rules are applied when 4gl variable are converted to/from JSON.

4GL to JSON conversion rules

Original 4GL datatype	Resulting JSON string
RECORD	a util.JSONObject in this form: { "record-element-name" : json-value [,...] }
DYNAMIC ARRAY	a util.JSONArray in this form: [ json-value [,...] ]
BOOLEAN	a JSON `TRUE` or `FALSE`
TINYINT SMALLINT INTEGER BIGINT SMALLFLOAT FLOAT DECIMAL MONEY	a sequence of characters in this form: -{0..9}.exponent Above and below, these are regular items, and these are optional ones Exponents get this form: e-{0..9} Representation of numeric values does not depend on the current locale. MONEY values are represented as DECIMAL values. Currency symbol is omitted. Decimal separator is always . (dot) and never , (comma).
INTERVAL	is formatted as `"YYYY-MM"` or `"DD hh:mm:ss.fffff"` (in double quotes) depending on the definition of the interval type
BYTE	a Base64-encoded double-quoted string
TEXT CHAR VARCHAR STRING	a double-quoted string with backslash escaping (if necessary) These characters require escaping: \\ backslash, U+005C \" quotation mark, U+0022 \b backspace, U+0008 \f form feed, U+000C \n line feed, U+000A \r carriage return, U+000D \t tab, U+0009

Values of any other datatype are converted to a double-quoted string.

JSON to 4GL conversion rules

Original JSON string	Resulting 4GL datatype
util.JSONObject in this form: { "record-element-name" : json-value [,...] }	RECORD
util.JSONArray in this form: [ json-value [,...] ]	DYNAMIC ARRAY
JSON `NULL`, `TRUE`, or `FALSE` If the JSON value is a number or a string, the rules are applied for converting number/string to BOOLEAN	BOOLEAN
JSON number JSON numbers can be converted to a value of any numeric datatype. Overflows errors may occur because of the limits of the target datatype. If any error occurs, the target variable will be initialized to NULL, and the parser will continue without errors.	TINYINT SMALLINT INTEGER BIGINT SMALLFLOAT FLOAT DECIMAL MONEY
JSON string formatted as `"YYYY-MM-DD"`	DATE
JSON string representing a datetime or a JSON number If the value is a JSON string, it must be formatted as `"YYYY-MM-DD hh:mm:ss.fffff"`, or be an ISO8601-formatted datetime, in UTC (with Z) or with a timezone offset (+/-hh[:mm]) - e.g., `"2018-04-05T1` If the value is a JSON number, it is interpreted as the UNIX™ time (in seconds since Unix epoch). `YYYY-MM-DD hh:mm:ss.ffff` is used for local time. When exchanging datetime values across different time zones, we recommend converting datetime values to Coordinated Universal Time (UTC) by the util.Datetime methods.	DATETIME
JSON string formatted as `"YYYY-MM"` or `"DD hh:mm:ss.fffff"`, depending on the interval class of the target variable	INTERVAL
JSON string encoded in Base64	BYTE
JSON string or number For JSON numbers, the resulting 4GL string will use the locale-specific decimal point. For JSON strings, any character in the Basic Multilingual Plane (U+0000 through U+FFFF) may be escaped: \u followed by exactly 4 hexadecimal digits ([0-9a-fA-F]) The hexadecimal digits encode the code point. characters outside the Basic Multilingual Plane may be escaped by their UTF-16 surrogate pairs - e.g., G-clef (U+1D11E) may be represented as `"\uD834\uDD1E"`.	TEXT CHAR VARCHAR STRING

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