19.13. Transformation Function Usage¶
19.13.1. Control Functions¶
19.13.1.1. try¶
Description: Execute another function - if it fails, instead use a default value
Usage: try($1, $2)
Example: try("1"::int, 0) = 1
Example: try("abcd"::int, 0) = 0
19.13.1.2. withDefault¶
Description: Replace a value with a default, if the value is null
Usage: withDefault($1, $2)
Example: withDefault('foo', 'bar') = foo
Example: withDefault(null, 'bar') = bar
19.13.2. String Functions¶
19.13.2.1. strip¶
Description: Removes characters from the start or end of a string. Defaults to whitespace.
Usage: strip($1) or strip($1, $chars)
Examples: strip('afoob', 'abc') = foo
strip('foao', 'abc') = foao
strip('\t foo ') = foo
19.13.2.2. stripQuotes¶
Description: Remove double or single quotes from a the start or end of a string
Usage: stripQuotes($1)
Examples: stripQuotes('"foo"') = foo
stripQuotes('\'foo\'') = foo
stripQuotes('fo"o') = fo"o
19.13.2.3. stripPrefix¶
Description: Removes characters from the start of a string. Whitespace is preserved.
Usage: stripPrefix($1, $chars)
Examples: stripPrefix('afoob', 'abc') = foob
19.13.2.4. stripSuffix¶
Description: Removes characters from the end of a string. Whitespace is preserved.
Usage: stripSuffix($1, $chars)
Examples: stripSuffix('afoob', 'abc') = afoo
19.13.2.5. remove¶
Description: Removes a substring from a string
Usage: remove($1, $substring)
Examples: remove('foabco', 'abc') = foo
19.13.2.6. replace¶
Description: Replaces a literal string with another string
Usage: replace($1, $toReplace, $replacement)
Examples: replace('foobar', 'ob', 'ab') = foabar
19.13.2.7. length¶
Description: Returns the length of a string.
Usage: length($1)
Example: length('foo') = 3
19.13.2.8. trim¶
Description: Trim whitespace from around a string.
Usage: trim($1)
Example: trim(' foo ') = foo
19.13.2.9. capitalize¶
Description: Capitalize a string.
Usage: capitalize($1)
Example: capitalize('foo') = Foo
19.13.2.10. lowercase¶
Description: Lowercase a string.
Usage: lowercase($1)
Example: lowercase('FOO') = foo
19.13.2.11. uppercase¶
Description: Uppercase a string.
Usage: uppercase($1)
Example: uppercase('foo') = FOO
19.13.2.12. regexReplace¶
Description: Replace a given pattern with a target pattern in a string.
Usage: regexReplace($regex, $replacement, $1)
Example: regexReplace('foo'::r, 'bar', 'foobar') = barbar
19.13.2.13. concatenate¶
Description: Concatenate two strings.
Usage: concatenate($0, $1)
Example: concatenate('foo', 'bar') = foobar
19.13.2.14. substring¶
Description: Return the substring of a string.
Usage: substring($1, $startIndex, $endIndex)
Example: substring('foobarbaz', 2, 5) = oba
19.13.2.15. toString¶
Description: Convert another data type to a string.
Usage: toString($0)
Example: concatenate(toString(5), toString(6)) = '56'
19.13.2.16. emptyToNull¶
Description: Replace an empty string with null. Useful for setting optional attributes from delimited
text files, where inputs will never be null.
Usage: emptyToNull($0)
Example: emptyToNull('') = null
19.13.2.17. printf¶
Description: Format custom strings. As an implementation detail, this function delegates to Java’s String formatting classes.
Usage: printf('patterns', $arg1, $arg2, ...)'
- Examples:
printf('%s-%s-%sT00:00:00.000Z', '2015', '01', '01') = '2015-01-01T00:00:00.000Z' printf('%2f', divide(-1, 2, 3)) = '-0.17'
19.13.3. Date Functions¶
The following table summarizes the predefined date formats by name. For dates that don’t match any of these
formats, a custom format can be used with the date function. secsToDate and millisToDate can be used
for parsing intervals since the Java epoch. See below for full descriptions of each function.
| Function | Format | Example |
|---|---|---|
| basicIsoDate | yyyyMMdd |
20150101 |
| basicDateTime | yyyyMMdd'T'HHmmss.SSSZ |
20150101T000000.000Z |
| basicDateTimeNoMillis | yyyyMMdd'T'HHmmssZ |
20150101T000000Z |
| dateTime | yyyy-MM-dd'T'HH:mm:ss.SSSZZ |
2015-01-01T00:00:00.000Z |
| dateHourMinuteSecondMillis | yyyy-MM-dd'T'HH:mm:ss.SSS |
2015-01-01T00:00:00.000 |
| isoLocalDate | yyyy-MM-dd |
2015-01-01 |
| isoLocalDateTime | yyyy-MM-dd'T'HH:mm:ss |
2015-01-01 |
| isoOffsetDateTime | yyyy-MM-dd'T'HH:mm:ssZ |
2015-01-01T00:00:00Z |
19.13.3.2. date¶
Description: Custom date parser. The date format is defined by the Java 8 DateTimeFormatter class.
Usage: date($format, $1)
Example:
date('yyyy-MM-dd\\'T\\'HH:mm:ss.SSSSSS', '2015-01-01T00:00:00.000000')
19.13.3.3. basicIsoDate¶
Description: A date format for yyyyMMdd, equivalent to java.time.format.DateTimeFormatter.BASIC_ISO_DATE.
Usage: basicIsoDate($1)
Example: basicIsoDate('20150101')
19.13.3.4. basicDateTime¶
Description: A date format that combines a basic date and time for yyyyMMdd'T'HHmmss.SSSZ.
Usage: basicDateTime($1)
Example: basicDateTime('20150101T000000.000Z')
19.13.3.5. basicDateTimeNoMillis¶
Description: A basic format that combines a basic date and time with no
millis for format yyyyMMdd'T'HHmmssZ.
Usage: basicDateTimeNoMillis($1)
Example: basicDateTimeNoMillis('20150101T000000Z')
19.13.3.6. dateTime¶
Description: A strict ISO 8601 Date parser for format
yyyy-MM-dd'T'HH:mm:ss.SSSZZ.
Usage: dateTime($1)
Example: dateTime('2015-01-01T00:00:00.000Z')
19.13.3.7. dateHourMinuteSecondMillis¶
Description: Formatter for full date, and time keeping the first 3
fractional seconds for format yyyy-MM-dd'T'HH:mm:ss.SSS.
Usage: dateHourMinuteSecondMillis($1)
Example: dateHourMinuteSecondMillis('2015-01-01T00:00:00.000')
19.13.3.8. isoLocalDate¶
Description: A date format for yyyy-MM-dd, equivalent to java.time.format.DateTimeFormatter.ISO_LOCAL_DATE.
Usage: isoLocalDate($1)
Example: isoLocalDate('2015-01-01')
19.13.3.9. isoLocalDateTime¶
Description: A date format for yyyy-MM-dd'T'HH:mm:ss, equivalent to
java.time.format.DateTimeFormatter.ISO_LOCAL_DATE_TIME.
Usage: isoLocalDateTime($1)
Example: isoLocalDateTime('2015-01-01T00:00:00')
19.13.3.10. isoOffsetDateTime¶
Description: A date format for yyyy-MM-dd'T'HH:mm:ssZ, equivalent to
java.time.format.DateTimeFormatter.ISO_OFFSET_DATE_TIME.
Usage: isoOffsetDateTime($1)
Example: isoOffsetDateTime('2015-01-01T00:00:00Z')
19.13.3.11. millisToDate¶
Description: Create a new date from a long representing milliseconds since January 1, 1970.
Usage: millisToDate($1)
Example: millisToDate('1449675054462'::long)
19.13.3.12. secsToDate¶
Description: Create a new date from a long representing seconds since January 1, 1970.
Usage: secsToDate($1)
Example: secsToDate(1449675054)
19.13.4. Geometry Functions¶
19.13.4.1. point¶
Description: Parse a Point geometry from lon/lat, WKT or WKB.
Usage: point($lon, $lat) or point($wkt)
Note: Ordering is important here…GeoMesa defaults to longitude first
Example: Parsing lon/lat from JSON:
Parsing lon/lat
# config
{ name = "lon", json-type="double", path="$.lon" }
{ name = "lat", json-type="double", path="$.lat" }
{ name = "geom", transform="point($lon, $lat)" }
# data
{
"lat": 23.9,
"lon": 24.2,
}
Example: Parsing lon/lat from text without creating lon/lat fields:
# config
{ name = "geom", transform="point($2::double, $3::double)" }
# data
id,lat,lon,date
identity1,23.9,24.2,2015-02-03
Example: Parsing WKT as a point
# config
{ name = "geom", transform="point($2)" }
# data
ID,wkt,date
1,POINT(2 3),2015-01-02
19.13.4.2. multipoint¶
Description: Parse a multi-point from a WKT string or WKB byte array.
Usage: multipoint($0)
Example: multipoint('MULTIPOINT ((10 40), (40 30), (20 20), (30 10))')
19.13.4.3. linestring¶
Description: Parse a linestring from a WKT string or WKB byte array.
Usage: linestring($0)
Example: linestring('LINESTRING(102 0, 103 1, 104 0, 105 1)')
19.13.4.4. multilinestring¶
Description: Parse a multi-linestring from a WKT string or WKB byte array.
Usage: multilinestring($0)
Example: multilinestring('MULTILINESTRING ((10 10, 20 20, 10 40), (40 40, 30 30, 40 20, 30 10))')
19.13.4.5. polygon¶
Description: Parse a polygon from a WKT string or WKB byte array.
Usage: polygon($0)
Example: polygon('POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))')
19.13.4.6. multipolygon¶
Description: Parse a multi-polygon from a WKT string or WKB byte array.
Usage: multipolygon($0)
Example: multipolygon('MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)), ((15 5, 40 10, 10 20, 5 10, 15 5)))')
19.13.4.7. geometrycollection¶
Description: Parse a geometry collection from a WKT string or WKB byte array.
Usage: geometrycollection($0)
Example: geometrycollection('GEOMETRYCOLLECTION(POINT(4 6),LINESTRING(4 6,7 10))')
19.13.4.8. geometry¶
Description: Parse a geometry from a WKT string or WKB byte array.
Usage: geometry($0)
Example: Parsing WKT as a geometry
# config
{ name = "geom", transform="geometry($2)" }
# data
ID,wkt,date
1,POINT(2 3),2015-01-02
2,"LINESTRING(102 0, 103 1, 104 0, 105 1)",2015-01-03
19.13.4.9. projectFrom¶
Description: Project a geometry from its native CRS to EPSG:4326. GeoMesa only supports EPSG:4326, so geometries must be transformed when ingesting from another CRS.
Usage: projectFrom('EPSG:3857',$0)
Example: Reprojecting a parsed point from EPSG:3857 to EPSG:4326:
# config
{ name = "geom", transform="projectFrom('EPSG:3857',point($2::double, $3::double))" }
# data
id,x,y,date
identity1,1689200.14,1113194.91,2015-02-03
19.13.5. ID Functions¶
19.13.5.1. stringToBytes¶
Description: Converts a string to a UTF-8 byte array (to pass to md5() or base64()).
Usage: stringToBytes($0)
Example: stringToBytes('row,of,data')
19.13.5.2. md5¶
Description: Creates an MD5 hash from a byte array.
Usage: md5($0)
Example: md5(stringToBytes('row,of,data'))
19.13.5.3. murmur3_32¶
Description: Creates a 32-bit murmur3 hash from a string.
Usage: murmur3_32($0)
Example: murmur3_32('row,of,data')
19.13.5.4. murmur3_128¶
Description: Creates a 128-bit murmur3 hash from a string. Note that previously this function was incorrectly
named murmur3_64, and can still be invoked by that name.
Usage: murmur3_128($0)
Example: murmur3_128('row,of,data')
19.13.5.6. uuidZ3¶
Description: Generates a Z3-based UUID for point geometries.
Usage: uuidZ3($geom, $date, $interval)
Example: uuidZ3(point('POINT (3 2)'), dateTime('2015-01-01T00:00:00.000Z'), 'week')
See Configuring Z-Index Time Interval for details on Z3 intervals.
19.13.5.7. uuidZ3Centroid¶
Description: Generates a Z3-based UUID for non-point geometries.
Usage: uuidZ3Centroid($geom, $date, $interval)
Example: uuidZ3Centroid(linestring('LINESTRING(102 0, 103 1, 104 0, 105 1)', dateTime('2015-01-01T00:00:00.000Z'), 'week')
See Configuring Z-Index Time Interval for details on Z3 intervals.
19.13.5.8. base64¶
Description: Encodes a byte array as a base-64 string.
Usage; base64($0)
Example: base64(stringToBytes('foo'))
19.13.6. Type Conversions¶
19.13.6.1. ::int or ::integer¶
Description: Converts a string into an integer. Invalid values will cause the record to fail.
Example: '1'::int = 1
19.13.6.2. ::long¶
Description: Converts a string into a long. Invalid values will cause the record to fail.
Example: '1'::long = 1L
19.13.6.3. ::float¶
Description: Converts a string into a float. Invalid values will cause the record to fail.
Example: '1.0'::float = 1.0f
19.13.6.4. ::double¶
Description: Converts a string into a double. Invalid values will cause the record to fail.
Example: '1.0'::double = 1.0d
19.13.6.5. ::boolean¶
Description: Converts a string into a boolean. Invalid values will cause the record to fail.
Example: 'true'::boolean = true
19.13.6.6. ::r¶
Description: Converts a string into a Regex object.
Example: 'f.*'::r = f.*: scala.util.matching.Regex
19.13.6.7. stringToInt or stringToInteger¶
Description: Converts a string into a integer, with a default value if conversion fails.
Usage: stringToInt($1, $2)
Example: stringToInt('1', 0) = 1
Example: stringToInt('', 0) = 0
19.13.6.8. stringToLong¶
Description: Converts a string into a long, with a default value if conversion fails.
Usage: stringToLong($1, $2)
Example: stringToLong('1', 0L) = 1L
Example: stringToLong('', 0L) = 0L
19.13.6.9. stringToFloat¶
Description: Converts a string into a float, with a default value if conversion fails.
Usage: stringToFloat($1, $2)
Example: stringToFloat('1.0', 0.0f) = 1.0f
Example: stringToFloat('not a float', 0.0f) = 0.0f
19.13.6.10. stringToDouble¶
Description: Converts a string into a double, with a default value if conversion fails.
Usage: stringToDouble($1, $2)
Example: stringToDouble('1.0', 0.0) = 1.0d
Example: stringToDouble(null, 0.0) = 0.0d
19.13.6.11. stringToBoolean¶
Description: Converts a string into a boolean, with a default value if conversion fails.
Usage: stringToBoolean($1, $2)
Example: stringToBoolean('true', false) = true
Example: stringToBoolean('55', false) = false
19.13.7. Math Functions¶
Usage:
All math functions accept: Integers, Doubles, Floats, Longs and parsable Strings.
All math functions return: Doubles. If another data type is needed, convert the value afterwards. e.g. add($1,$2)::long
Example:
{ name = "value3", transform = "add($value1, multiply($value2, 1.2))::double" }
19.13.7.2. subtract¶
Description: Subtracts two or more values.
Example: subtract($1,$2)
Example: subtract($1,$2,1.0f)
19.13.7.3. multiply¶
Description: Multiply two or more values.
Example: multiply($1,$2)
Example: multiply($1,$2,0.01d)
19.13.7.4. divide¶
Description: Divides two or more values sequentially.
Example: divide($1,$2)
Example: divide($1,$2,"15") is equivalent to ($1/$2)/"15"
19.13.7.5. mean¶
Description: Takes the mean (average) of two or more numbers.
Example: mean($1,$2,$3)
19.13.8. List and Map Functions¶
19.13.8.2. mapValue¶
Description: Read a value out of a map instance by key
Example: mapValue($map,'key')
19.13.8.3. parseList¶
Description: Parse a List[T] type from a string.
If your SimpleFeatureType config contains a list or map you can easily
configure a transform function to parse it using the parseList
function which takes either 2 or 3 args
- The primitive type of the list (int, string, double, float, boolean, etc)
- The reference to parse
- Optionally, the list delimiter (defaults to a comma)
Here’s some sample CSV data:
ID,Name,Age,LastSeen,Friends,Lat,Lon
23623,Harry,20,2015-05-06,"Will, Mark, Suzan",-100.236523,23
26236,Hermione,25,2015-06-07,"Edward, Bill, Harry",40.232,-53.2356
3233,Severus,30,2015-10-23,"Tom, Riddle, Voldemort",3,-62.23
For example, an SFT may specific a field:
{ name = "friends", type = "List[String]" }
And a transform to parse the quoted CSV field:
{ name = "friends", transform = "parseList('string', $5)" }
19.13.8.4. parseMap¶
Description: Parse a Map[T,V] type from a string.
Parsing Maps is similar. Take for example this CSV data with a quoted map field:
1,"1->a,2->b,3->c,4->d",2013-07-17,-90.368732,35.3155
2,"5->e,6->f,7->g,8->h",2013-07-17,-70.970585,42.36211
3,"9->i,10->j",2013-07-17,-97.599004,30.50901
Our field type is:
numbers:Map[Integer,String]
Then we specify a transform:
{ name = "numbers", transform = "parseMap('int -> string', $2)" }
Optionally we can also provide custom list/record and key-value delimiters for a map:
{ name = "numbers", transform = "parseMap('int -> string', $2, '->', ',')" }
19.13.9. State Functions¶
19.13.9.1. inputFilePath¶
Description: provides the absolute path to the file being operated on, if available
Example: $inputFilePath
The file path is a variable, referenced through $ notation.
The file path may not always be available, depending on how the converter is being invoked. When invoked through the GeoMesa command-line tools or GeoMesa NiFi, it will be set appropriately.
19.13.9.2. lineNo¶
Description: provides the current line number in the file being operated on, if available
Example: lineNo()
The line number may not always be available, depending on the converter being used. For some converters, line number may be an abstract concept. For example, in the Avro converter line number will refer to the number of the Avro record in the file.