Expression language is PDF Generator API specific programming language that allows to write mathematical and logical expression to manipulate the value displayed by component.

{% 2 + {dataFieldName} + {dataFieldName2}*0.5 %}

Supported operators

1. Arithmetic Operators

• + (addition)
• – (subtraction)
• * (multiplication)
• / (division)
• % (modulus)
• ** (pow)

2. Bitwise Operators

• & (and)
• | (or)
• ^ (xor)

3. Comparison Operators

• == (equal)
• === (identical)
• != (not equal)
• !== (not identical)
• < (less than) > (greater than)
• <= (less than or equal to) >= (greater than or equal to)
• matches (regex match) e.g {% {dataField} matches "/bar/" ? "yes" : "no" %}

4. Array

• in (contain)
• not in (does not contain)

5. String

• ~ (concatenation)

Ternary Operators

{% {financial_status} === 'paid' ? 'All paid' : 'Waiting for payment' %}

{% {financial_status} === 'paid' ? uppercase({financial_status}) : 'Waiting for payment' %}

Functions

Uppercase

To display data field value in uppercase, use following expression.
{% uppercase({dataFieldName}) %}

Lowercase

To display data field value in lowercase, use following expression.
{% lowercase({dataFieldName}) %}

Capitalize

Uppercase the first character of each word in a string.
{% capitalize({dataFieldName}) %}

Example: {% capitalize('hello word') %} => Hello Word

Sum

It is possible to calculate sum of table column using following code
{% sum({line_items::amount}) %}

Sumproduct

The sumproduct function multiplies the corresponding items in the arrays and returns the sum of the results.
{% sumproduct({line_items::amount},{line_items::price}, {line_items::anotherColumn}) %}

Average

It is possible to calculate average of table column using following code
{% avg({line_items::amount}) %}

Count

It is possible to count number of items in list
{% count({line_items}) > 3 ? 'More than three' : 'Less than three' %}

Empty

The empty function checks if field has value.
{% empty({dataField}) ? 'No value' : 'Field has value' %}

Join

The join(delimiter, array) function concatenates field values with specified separator. Last arguments is always used as the separator.
{% join(";", {field1}, {field2}, {field3}, ..., {fieldN}) %}

Split

The split(delimiter, string) function allows to split string into an array
{% split("_", "Some_string") %} => ["Some", "string"]

Date

Format date value. NB! You need to use the Date formatter.
{% date({dateString}, {timezone}, {addDays}, {outputFormat}) %}

Examples:
Display current time - {% date('now') %}
Specify timezone - {% date({dateValue}, 'UTC') %}

Format	Description	Example
Day
d	Day of the month, 2 digits with leading zeros	01 to 31
D	A textual representation of a day, three letters	Mon through Sun
j	Day of the month without leading zeros	1 to 31
l	A full textual representation of the day of the week	Sunday through Saturday
Month
F	A full textual representation of a month, such as January or March	January through December
m	Numeric representation of a month, with leading zeros	01 through 12
M	A short textual representation of a month, three letters	Jan through Dec
n	Numeric representation of a month, without leading zeros	1 through 12
Year
Y	A full numeric representation of a year, 4 digits	Examples: 1999 or 2003
y	A two digit representation of a year	Examples: 99 or 03
Timezone
O	Difference to Greenwich time (GMT) in hours	Example: +0200
P	Difference to Greenwich time (GMT) with colon between hours and minutes (added in PHP 5.1.3)	Example: +02:00
T	Timezone abbreviation	Examples: EST, MDT ...
Z	Timezone offset in seconds. The offset for timezones west of UTC is always negative, and for those east of UTC is always positive.	-43200 through 50400

Datetime

Format datetime value. NB! You need to use the Date formatter.
{% datetime({datetimeString}, {timezone}, {addDays}, {outputFormat}) %}

Examples:
Display current time - {% datetime('now') %}
Specify timezone - {% datetime({dateValue}, 'UTC') %}

Format	Description	Example
Time
a	Lowercase Ante meridiem and Post meridiem	am or pm
A	Uppercase Ante meridiem and Post meridiem	AM or PM
G	24-hour format of an hour without leading zeros	0 through 23
h	12-hour format of an hour with leading zeros	01 through 12
H	24-hour format of an hour with leading zeros	00 through 23
i	Minutes with leading zeros	00 to 59
s	Seconds with leading zeros	00 through 59

Max

Returns maximum value of list of elements or separate field values.
{% max({line_items::quantity}) %} or {% max({dataField1}, {dataField2}, ..., {dataFieldN}) %}

Min

Returns minimum value of list of elements or separate field values.
{% min({line_items::quantity}) %} or {% min({dataField1}, {dataField2}, ..., {dataFieldN}) %}

Iterate list of elements (array map)

Iterates over list of elements and executes expression for each element. Returns new list.
{% iterate({line_items}, '{quantity}*{price}') %}

Collect unique values from list

Collects unique values from and counts them. Returns new list with following structure: [{"value": "Value", "count": 3, "raw_value": "Value"}, {"value": "Value 2", "count": 1, "raw_value": "Value 2"}]
{% collect_unique_values({array}, {array_of_values_to_exclude}, {expression_to_execute_for_each_item}) %}

Flatten list

Flattens list.
{% flatten(iterate({orders}, "{line_items}")) %}

JSON decode

Decode JSON string to use in an expression.
{% json_decode('{"key": "value"}', true) %}