Filters

Filters transform values after they're resolved. They let you manipulate text, process arrays, format numbers, and much more. Filters are comma-separated and can be chained together for powerful data transformations.

String Filters

Filter	Syntax	Description
Truncate	`truncate N`	Shorten to N characters, append `...`
Replace	`replace "X" with "Y"`	Replace all occurrences of X with Y
URL Encode	`url_encode`	Percent-encode for use in URLs
Strip HTML	`strip_html`	Remove all HTML tags
Trim	`trim`	Remove leading and trailing whitespace
Newline to BR	`newline_to_br`	Convert line breaks to `<br>` tags
Split	`split "sep"`	Split a string into an array

Truncate

Template

{the user's Bio, truncate 50}

Output

Jane is a marketing professional who specializes...

Replace

Template

{the user's Code, replace "-" with " "}

Output

ABC 123

URL Encode

Template

{the user's Email, url_encode}

Output

jane%40example.com

Strip HTML (input: <b>Bold</b> text and more)

Template

{the user's Bio, strip_html}

Output

Bold text and more

Trim (input: ' Jane Doe ')

Template

{the user's Name, trim}

Output

Jane Doe

Newline to BR

Template

{the user's Note, newline_to_br}

Output

Line one<br>Line two

Split into array

Template

{the user's Name, split " "}

Output

["Jane", "Doe"]

Array Filters

Filter	Syntax	Description
Join	`join "sep"`	Join array elements with a separator
First	`first`	Get the first element
Last	`last`	Get the last element
Length	`length` or `size`	Count the number of elements
Sort	`sort`	Sort alphabetically (case-insensitive)
Reverse	`reverse`	Reverse the order
Unique	`unique`	Remove duplicates (preserves order)
Where	`where "attr" is "val"`	Filter list of objects by attribute value
Map	`map "attr"`	Extract one field from each object
Slice	`slice N M`	Get a sub-array from index N to M

Join

Template

{the user's Tags, join ", "}

Output

vip, active, premium

First

Template

{the user's Items, first}

Output

Widget

Last

Template

{the user's Items, last}

Output

Gadget

Length

Template

{the user's Items, length}

Output

Sort

Template

{the user's Tags, sort}

Output

["active", "premium", "vip"]

Reverse

Template

{the user's Items, reverse}

Output

["Gadget", "Alpha", "Widget"]

Unique (removes duplicate 'vip')

Template

{the user's Tags, unique}

Output

["vip", "active"]

Where filter

Template

{the user's Orders, where "status" is "active"}

Output

[{name: "Widget", status: "active"}]

Map

Template

{the user's Orders, map "name"}

Output

["Widget", "Gadget", "Alpha"]

Slice (first 3 items)

Template

{the user's Items, slice 0 3}

Output

["Widget", "Gadget", "Alpha"]

Number Filters

Filter	Syntax	Description
Round	`round N`	Round to N decimal places
Default	`default "val"`	Fallback on null, empty string, and zero

Round

Template

{the user's Score, round 2}

Output

3.14

Default (when value is null)

Template

{the user's Name, default "Guest"}

Output

Guest

default vs or

Warning

The default filter and the or modifier behave differently:

or "value" triggers only when the data is null/missing
default "value" triggers on null, empty string "", and zero 0

Use or when you only want to replace missing values. Use default when you also want to replace empty strings and zeros.

Scenario	`or "Guest"`	`default "Guest"`
Value is `null`	Guest	Guest
Value is `""` (empty)	(empty)	Guest
Value is `0`	0	Guest
Value is `"Jane"`	Jane	Jane

Chaining Filters

Filters apply left-to-right -- the output of each filter becomes the input for the next. This lets you build powerful transformation pipelines:

Chain: strip HTML, truncate, then trim

Template

{the user's Bio, strip_html, truncate 100, trim}

Output

Clean truncated text from a long HTML bio...

Chain: filter, extract, sort, join

Template

{the user's Orders, where "status" is "active", map "name", sort, join ", "}

Output

Alpha, Widget

Chain: split then get first

Template

{the user's Name, split " ", first}

Output

Jane

Chain: deduplicate, sort, join

Template

{the user's Tags, unique, sort, join " | "}

Output

active | premium | vip

How Chaining Works (Step by Step)

Here's how {the user's Orders, where "status" is "active", map "name", sort, join ", "} is evaluated:

Resolve the user's Orders -- gets the full list of order objects
where "status" is "active" -- filters to only orders with status "active"
map "name" -- extracts just the name field from each order
sort -- sorts the names alphabetically
join ", " -- combines them into a comma-separated string

Tip

When chaining filters, think about what type of data each filter expects. Array filters like sort and join need arrays as input. String filters like truncate need strings. The split filter converts a string to an array, and join converts an array back to a string.

Complete Filter Reference

Filter	Syntax	Input Type	Output Type
`truncate`	`truncate N`	String	String
`replace`	`replace "X" with "Y"`	String	String
`url_encode`	`url_encode`	String	String
`strip_html`	`strip_html`	String	String
`trim`	`trim`	String	String
`newline_to_br`	`newline_to_br`	String	String
`split`	`split "sep"`	String	Array
`join`	`join "sep"`	Array	String
`first`	`first`	Array	Any
`last`	`last`	Array	Any
`length` / `size`	`length`	Array/String	Number
`sort`	`sort`	Array	Array
`reverse`	`reverse`	Array	Array
`unique`	`unique`	Array	Array
`where`	`where "attr" is "val"`	Array	Array
`map`	`map "attr"`	Array	Array
`slice`	`slice N M`	Array	Array
`round`	`round N`	Number	Number
`default`	`default "val"`	Any	Any