Exportizer Users' Guide vlsoftware.net

Expression Engine

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Exportizer Pro expression engine allows you to execute Pascal-like expressions, which can be embedded in dynamic elements during export (for example, in field mappings or when exporting database data to HTML using HTML templates).

The expressions can consist of functions (nesting of any depth), arithmetical and logical operators, and literals (numeric, string, or boolean). Expression returns one value of numeric, string, or boolean type.

Notes

1. The expressions and functions are calculated "on the fly" before they are outputted to target document or table.

2. Names of functions and operators are case insensitive.

3. Parameters of parameterized functions may be constants (literals) or expressions.

4. String literals must be enclosed in single quotes. If a literal includes quote marks, each of them must be doubled.

5. Multi-line string literals are not allowed. If you want to pass big text as parameter, you can split it on less separate string literals and concatenate them using + operator.

6. In some functions, there is a StepNo parameter. It is meaningful only when used in HTML templates (see below), in all other cases it should be 1.

HTML template can be filled with dynamic data in more than one step. For example, if your HTML document consists of several tables, which must be filled with database data from different datasets, you can fill them only in several export steps (usually, one dataset per step). That's why database related and some other functions have a StepNo parameter. When exporting a dataset to HTML using HTML template, it is also possible to specify an export step number (it is 1 by default). During the export procedure, only those expressions will be calculated where the StepNo parameter of expression function(s) is not present or matches with a step number, specified in export options. For example, the database_field_val(2, 'payment_sum')/100 expression will be calculated only in the second export step.

Combining different StepNo parameters in one expression (for example, database_field_val(1, 'total_sum') + database_field_val(2, 'payment_sum')) is possible, but such expression should be written so that functions with smaller StepNo will be calculated earlier.

Examples of valid expressions:

12 + abs(sqrt(5) - 2)/3 Arithmetic expression
25 - 5 >= 14 Logical expression
'File name: ' + dataset_field_val(1, 'FileName') String expression
date + 4 Date expression. Adds four days to current date. It is vaild because dates are compatible with numbers.
iif(length(Target_File_Name(1)) > 25, 'yes', 'no') Complex expression

Examples of invalid expressions:

12 / target_file_name(1) Illegal use of string function in arithmetic expression (type mismatch)
concat(cos(dataset_field_val(1, 'FuncParam')), ' is larger') Illegal use of floating point number as an argument of string concatenation. There must be explicit type casting using to_string function.
5 <> False Illegal comparison of a numeric and boolean constants
power(4) Missing a second argument for power function
iif(length(Target_File_Name(1) > 25, 'yes', 'no') Missing right parenthesis for length function

Here, the expression engine operators and functions are described.

Operators

Arithmetic. Work with numbers and return numbers (except + operator, which can be used for string concatenation).
+ Addition of numbers. Can be also used for concatenating string operands (as an alternative for concat function).
- Substraction of numbers
* Multiplication of numbers
/ Division of numbers
^ Raises left operand to power, specified by the right operand (as an alternative for power function)
div Integer division. It is division in which the fractional part (remainder) is discarded.
mod Remainder of integers. It divides two numbers and returns only the remainder.
Logical. Work with boolean constants or expressions of any kind, which return a boolean value, and return boolean True or False.
not Logical NOT. Returns False if its single operand can be converted to True; otherwise, returns True.
and Logical AND. Returns True if both operands are True; otherwise, returns False.
or Logical OR. Returns True if either operand is True; if both are False, returns False.
xor Exclusive OR. Returns True if one operand is True and the other is False; otherwise, returns False.
= Equality
<> Inequality
> Greater than
>= Greater than or equal
< Less than
<= Less than or equal

Functions

Use functions to calculate values.

Each function returns one value. Function parameters can be constants or expressions (including recursive function calls), unless otherwise noted below.

Database related

StepNo parameter specifies the export step, in which the function must be calculated (see note 6 here). It is used only in HTML export context; in other cases its value is ignored.

General
dataset_field_val( StepNo Integer, FieldName String ): <FieldType> Returns value of field FieldName of the current dataset. The type of the returned value depends on the database field type.
dataset_param_val( StepNo Integer, ParamName String ): <ParamType> Returns value of query parameter ParamName (if the current dataset is a parameterized query). The type of the returned value depends on the parameter type.
dataset_field_is_null( StepNo Integer, FieldName String ): Boolean Returns True, when value of field FieldName of the current dataset is null, and False in other cases.
dataset_nvl( StepNo Integer, FieldName String, SubstVal <FieldType> ): <FieldType> Returns SubstVal, when value of field FieldName of the current dataset is null, and the field value in another case. The type of SubstVal must match the type of the FieldName field.
query_res( StepNo Integer, SqlText String ): <FieldType> Returns result of the one-field query, specified by SQL text SqlText. The type of the returned value depends on the database field type.

Statistical (aggregate)

These functions perform calculation on current dataset data. Unlike other functions, statistical functions accumulate data of each record of dataset field, therefore they need more resources and their using (especially for conditional functions) may slow up processing for large datasets.

It is strongly recommended to use these functions only inside or after loop(s) through dataset rows, otherwise they will return inadequate values.

GroupLevel is reserved for future use and currently must be 0.

Standard (similar to aggregate functions in SQL)
dataset_row_count( StepNo Integer, GroupLevel Integer ): Integer Returns the current dataset row count (accumulating). Actually, inside the dataset rows loop, it returns the current row number.
dataset_min( StepNo Integer, GroupLevel Integer, FieldName String ): Integer Returns the lowest value in FieldName
dataset_max( StepNo Integer, GroupLevel Integer, FieldName String ): Integer Returns the highest value in FieldName
dataset_sum( StepNo Integer, GroupLevel Integer, FieldName String ): Integer Sums values in FieldName
dataset_avg( StepNo Integer, GroupLevel Integer, FieldName String ): Integer Returns the average value in FieldName
dataset_count( StepNo Integer, GroupLevel Integer, FieldName String ): Integer Returns count of non-empty values in FieldName

Conditional

These functions work like standard statistical functions, but with one important difference: they check Condition for each row, and calculate only if it evaluates to True. It is important to write the Condition parameter in these functions as String constant (i.e. enclosed in single quotes) or a string deterministic expression (see below).

The parameters of these functions must be constants or deterministic expressions (i.e. return the same result any time they are called with a specific set of input values). The Condition parameter can use also nondeterministic expressions, but, as noted above, it should be written as string literal or string deterministic expression.

dataset_row_count_ex( StepNo Integer, GroupLevel Integer, Condition String ): Integer
dataset_min_ex( StepNo Integer, GroupLevel Integer, FieldName String, Condition String ): Integer
dataset_max_ex( StepNo Integer, GroupLevel Integer, FieldName String, Condition String ): Integer
dataset_sum_ex( StepNo Integer, GroupLevel Integer, FieldName String, Condition String ): Integer
dataset_avg_ex( StepNo Integer, GroupLevel Integer, FieldName String, Condition String ): Integer
dataset_count_ex( StepNo Integer, GroupLevel Integer, FieldName String, Condition String ): Integer

Note

It is not recommended to use nested calls of statistical functions (i.e. when Condition contains statistical functions calls), because the program cannot guarantee the correct result of such calls.

But if you do this, try to avoid cyclic field references in these functions because this may cause unexpected results of expressions. For example, using FieldName inside Condition is a cyclic reference and should be avoided.

Examples of correct using of conditional statistical functions:

dataset_sum_ex(1, 0, 'PaymentSum', 'dataset_field_val(1, ''CustNo'') > 1000')

(this expression will sum data from PaymentSum field, when value of numeric field CustNo is larger then 1000)

dataset_count_ex(1, 0, 'CustNo', 'dataset_field_val(1, ''Paid'')')

(this expression will return count of values from field CustNo, when value of boolean field Paid is True)

dataset_sum_ex(1, 0, 'BillSum', 'dataset_sum_ex(1, 0, ''OldBillSum'', ''dataset_field_val(1, ''''CustNo'''') > 0'') > 0')

(this function will return sum of values from field BillSum, when conditional sum of field OldBillSum is larger than 0)

Examples of incorrect using of conditional statistical functions:

dataset_count_ex(1, 0, 'CustNo', 'yes')

(error: not boolean constant cannot be used as condition)

dataset_sum_ex(1, 0, 'BillSum', 'dataset_sum_ex(1, 0, ''OldBillSum'', ''dataset_sum_ex(1, 0, ''''BillSum'''', True) > 0'') > 0')

(error: cyclic reference for field BillSum)

Mathematical

abs( x Numeric ): Numeric Returns an absolute value of numeric x
frac( x Numeric ): Numeric Returns fractional part of numeric x
int( x Numeric ): Numeric Returns integer part of numeric x
round( x Numeric ): Numeric Returns the value of numeric x rounded to the nearest whole number
sqrt( x Numeric ): Numeric Returns square root of numeric x
power( x Numeric, y Numeric ): Numeric Raises numeric base x to numeric power y
exp( x Numeric ): Numeric Returns the exponential of numeric x
ln( x Numeric ): Numeric Returns the natural (base e) logarithm of numeric x
cos( x Numeric ): Numeric Returns the cosine of numeric x, where x is given in radians
sin( x Numeric ): Numeric Returns the sine of numeric x, where x is given in radians
tan( x Numeric ): Numeric Returns the tangent of numeric x, where x is given in radians
atan( x Numeric ): Numeric Returns the arc tangent of numeric x, that is, the value whose tangent is x

Date and time

date: Date Returns current date
time: Time Returns current time
add_date_time( x DateTime, y Numeric ): DateTime Adds y days to date/time x. y can be an integer or floating-point number. For example, 2.5 means two days and 12 hours.
compare_date_time( Date1 DateTime, Date2 Numeric ): Numeric Returns an integer indicating the result of comparison of the date/time Date1 and date/time Date2: 0 when Date1 = Date2, 1 when Date1 > Date2, and -1 when Date1 < Date2.
date_time_diff( Date1 DateTime, Date2 DateTime ): Numeric Returns difference in days (as floating-point number) between date/time Date1 and date/time Date2
format_date_time( x DateTime, Mask String ): String Formats a date/time x using mask Mask. For example, to display only current month, use date for the first parameter and 'm' or 'mmmm' for the second one.

HTML related (work in HTML export context)

doc_title: String Returns HTML document title as it was specified in export options
target_file_name( StepNo Integer ): String Returns full path of target HTML file as it was specified in export options. StepNo specifies the export step, in which this function must be calculated (see note 6 here).

File related

file_created( FileName String ): DateTime Returns the date and time the file FileName was created. FileName should be full file path.
file_last_modified( FileName String ): DateTime Returns the date and time the file FileName was last modified. FileName should be full file path.
file_last_accessed( FileName String ): DateTime Returns the date and time the file FileName was last accessed. FileName should be full file path.
file_size( FileName String ): Numeric Returns the size of the file FileName in bytes. FileName should be full file path.
file_version( FileName String ): Numeric Returns the version of the file FileName. FileName should be full file path.
extract_file_ext( FileName String ): String Extracts the extension of the file FileName (with period)
extract_file_name( FileName String ): String Extracts file name from the full file path FileName
extract_file_dir( FileName String ): String Extracts file path (without \ character at the end) from the full file path FileName
extract_file_path( FileName String ): String Extracts file path (with \ character at the end) from the full file path FileName
extract_file_text( FileName String ): String Extracts text from the text file FileName. FileName should be full file path.
file_exists( FileName String ): Boolean Returns True if file FileName exists, False otherwise
dir_exists( DirectoryName String ): Boolean Returns True if directory DirectoryName exists, False otherwise

Miscelanious

to_number( x <AnyType> ): Numeric Converts x to number
to_string( x <AnyType> ): String Converts x to string
format_float( x Numeric, Mask String ): String Formats a numeric x using mask Mask. For example, to always display two decimal places after the floating point, use '0.00' for the second parameter.
lpad( Str String, Count Numeric, Char String ): String Adds Char characters to the left-side of a string Str. Count is the number of characters to return.
rpad( Str String, Count Numeric, Char String ): String Adds Char characters to the right-side of a string Str. Count is the number of characters to return.
iif( Condition Boolean, x <AnyType>, y <AnyType> ): <AnyType> Returns x if Condition evaluates to True, or y in another case
upper( Str String ): String Converts a string Str to upper case
lower( Str String ): String Converts a string Str to lower case
capitalize( Str String ): String Converts first characters of every word in a string Str to upper case
pretty( Str String ): String Makes the first character of string Str in upper case and the rest in lower case
length( Str String ): Integer Returns length (count of characters) of a string Str
pos( SubStr String, Str String ): Integer Returns position of substring SubStr in string Str
substr( Str String, Index Integer, Count Integer ): String Returns a substring of a string Str, containing Count characters starting at Index position
substr_count( Str String, SubStr String ): Integer Returns the number of times the substring SubStr occurs in string Str
trim( Str String ): String Trims leading and trailing spaces and control characters from a string Str
trim_left( Str String ): String Trims leading spaces and control characters from a string Str
trim_right( Str String ): String Trims trailing spaces and control characters from a string Str
string_replace( Str String, SubStr Integer, NewSubStr Integer ): String Replaces all occurancies of substring SubStr with substring NewSubStr in text Str
concat( Str1 String, Str2 Integer ): String Returns a string that is the result of concatenating string Str1 to string Str2
ordinal_number( x Integer, Language String, Case Integer, Gender Integer ): String

Returns the original number and the ordinal suffix of integer x.

Language is the language in which the result should be represented. Possible values: 'en-US' (American English), 'uk-UA' (Ukrainian).

Case (from 'A' to 'F') and Gender ('M', 'F', 'N') are for Ukrainian language only.

quantitative_numeral( x Integer, Language String, Case Integer, Gender Integer ): String

Returns the quantitative numeral of integer x.

Language is the language in which the result should be represented. Possible values: 'uk-UA' (Ukrainian).

Case (from 'A' to 'F') and Gender ('M', 'F', 'N') are for Ukrainian language only.

number_to_words( x Numeric, Language String, Options String ): String

Converts number x to its representation in words.

Language is the language in which the result should be represented. Possible values: 'en-US' (American English), 'uk-UA' (Ukrainian).

Options is a pipe separated list of options in OptionName=OptionValue format.
Allowed options:
- ShowZeroSubunits. Instructs either to include fractional part of the number if it equals to zero. Possible values: True or False. Default value: False.
- ProcessSubunits. Instructs either to convert fractional part of the number to words. Possible values: True or False. Default value: False.
- UnitsSubunitsSeparator. Specifies a separator between an integer and fractional parts of the number. Default value is a space character.
- SubunitsDimension. Specifies dimension for fractional part of the number. Default value is 2. This option is ignored when ProcessSubunits is True.
- CurrencyCode. Specifies currency code in ISO 4217 format. Currently, only the following currency codes are supported: USD, EUR, UAH. Using this option instructs to interpret the number as currency value and add main currency and fractional currency names (i.e., units and sub-units).
- Type. Specifies the type of the conversion. Possible values: regular, fraction. This option is meaningful only if Language is 'uk-UA'.
- UnitsShortened. Instructs to shorten the main currency name (units) if it is used. This option is meaningful only if Language is 'uk-UA'.
- SubunitsShortened. Instructs to shorten the fractional currency name (sub-units) if it is used. This option is meaningful only if Language is 'uk-UA'.

Examples:

Expression Result
number_to_words( dataset_field_val(1, 'pay_sum'), 'en-US', 'UnitsSubunitsSeparator= and |CurrencyCode=USD|SubunitsDimension=2|ShowZeroSubunits=true' )  
number_to_words( 3467.35, 'en-US', 'UnitsSubunitsSeparator= and |CurrencyCode=USD|ShowZeroSubunits=true' ) three thousand four hundred sixty seven dollars and 35 cents
number_to_words( 3467.35, 'en-US', 'UnitsSubunitsSeparator= and |SubunitsDimension=4|ShowZeroSubunits=true' ) three thousand four hundred sixty seven and 3500