Built-in Filters | Everkm Publish

lower

Converts letters to lowercase.

upper

Converts letters to uppercase.

wordcount

Returns the word count.

capitalize

Capitalizes the first letter of each word in a sentence.

title

Capitalizes the first letter of every word.

replace

Replaces a string.

{{ name | replace(from="Robert", to="Bob")}}

regex_replace

Regular expression replacement.

{{ name | regex_replace(from="\d+", to="$1")}}

addslashes

Escapes quotes.

{{ set value = "I'm using Daobox" }}
{{ value | addslashes }}

Output: I\\'m using Daobox

slugify

Converts to a URL-friendly slug string.

{{ set value = "-Hello world! " }}
{{ value | slugify }}

Output: hello-world

trim

Trims whitespace from both ends.

trim_start

Trims whitespace from the left side.

trim_end

Trims whitespace from the right side.

trim_start_matches

Trims characters matching a regex pattern from the left side.

{{ set value = "//a/b/c//" }}
{{ value | trim_start_matches(pat="//") }}

Output: a/b/c//

trim_end_matches

Trims characters matching a regex pattern from the right side.

{{ set value = "//a/b/c//" }}
{{ value | trim_start_matches(pat="//") }}

Output: //a/b/c

truncate

Truncates a string to the specified length. If the string is shorter than the limit, it is kept intact. After truncation, "..." is appended to the end; the suffix can be changed via the end parameter.

{{ value | truncate(length=10, end="") }}

linebreaksbr

Replaces newline characters (\n, \r\n) with <br>.

spaceless

Removes whitespace and newlines inside HTML tags.

{% set value = "<p>\n<a> </a>\r\n </p>" %}
{{ value | spaceless }}

Output: <p><a></a></p>

striptags

Strips HTML tags.

{% set value = "<b>Joel</b>" %}
{{ value | striptags }}

Output: Joel

first

Returns the first element of a list. Returns an empty string if the list is empty.

last

Returns the last element of a list. Returns an empty string if the list is empty.

nth

Returns the N-th element of a list (0-based index). Returns an empty string if the list is empty.

{{ value | nth(n=2) }}

join

Joins strings in a list with a separator.

{% set value = ['a', 'b', 'c'] %}
{{ value | join(sep=" // ") }}

Output: a // b // c

length

Returns the length of a list, object, or string.

index_of

Returns the position of the specified element in a list, starting from 0.

Parameters

Parameter	Meaning	Type	Optional	Notes
search	The list to search	list of elements

Returns

An integer. Returns -1 if not found.

e.g.

{% set s = "hello" %}
{{ s | index_of(search=["a", "b", "hello"]) }}

{# output: 2 #}

reverse

Returns a string or list in reverse order.

sort

Sorts a list. Elements in the list must be sortable.

Numbers are sorted by value.
Strings are sorted by ASCII order.
Lists are sorted by length.
Booleans: true=1, false=0.

If list elements are objects (key-value pairs), you can specify the attribute to sort by:

{% set people = [
  {
    "name": ["daobox", "yu"],
    "age": 30
  }
] %}

{# Sort by first name #}
{{ people | sort(attribute="name.0") }}

{# Sort by age #}
{{ people | sort(attribute="age") }}

unique

Deduplicates a list. Usage is the same as sort. When the reference value is a string, you can use case_sensitive to specify whether to ignore case.

{{ people | unique(attribute="age") }}
{{ people | unique(attribute="name.1", case_sensitive="true") }}

slice

Slices a list. Use the start and end parameters to specify the start and end indices (0-based). Returns a sublist from start (inclusive) to end (exclusive). Both parameters can be omitted, defaulting to the list boundaries.

{% for i in my_arr | slice(end=5) %}
{% for i in my_arr | slice(start=1) %}
{% for i in my_arr | slice(start=1, end=5) %}

Use negative indices to count from the end.

{% set  my_array = [1, 2, 3, 4, 5] %}
{{  my_arr | slice(end=-2) }}

Result: [1, 2, 3]

group_by

Groups a list. The attribute parameter specifies the grouping key. Returns an object (key-value pairs) where each key is an attribute value and each value is a list of elements with that attribute. Elements missing the grouping attribute are ignored.

Object definition example (pseudocode):

Author {
    name: String,
};

Post {
    content: String,
    year: u32,
    author: Author,
}

posts=[Post, Post]

Group by year:

{{ posts | group_by(attribute="year") }}

Group by author.name:

{% for name, author_posts in posts | group_by(attribute="author.name") %}
    {{ name }}
    {% for post in author_posts %}
        {{ post.year }}: {{ post.content }}
    {% endfor %}
{% endfor %}

Custom grouping:

{% set map = section.pages | group_by(attribute="year") %}
{% set_global years = [] %}
{% for year, ignored in map %}
    {% set_global years = years | concat(with=year) %}
{% endfor %}
{% for year in years | reverse %}
    {% set posts = map[year] %}
{% endfor %}

filter

Filters a list. Returns only elements whose attribute equals the specified value. Elements missing the attribute or with a null/empty value are ignored.

The attribute parameter is required. The value parameter can be omitted, which means elements with a null/empty attribute value are filtered out.

Author {
    name: String,
};

Post {
    content: String,
    year: u32,
    author: Author,
    draft: bool,
}

{{ posts | filter(attribute="draft", value=true) }}
{{ posts | filter(attribute="author.name", value="Vincent") }}

map

Extracts the specified attribute from each element and returns a list.

Name(String, String);

Person {
    name: Name,
    age: u32,
}

Return all ages:

{{ people | map(attribute="age") }}

concat

Appends one or more elements to a list.

{{ posts | concat(with=drafts) }}

urlencode

Encodes a string into a safe URL encoding. Per RFC3986, / is not encoded.

{% set value = "/foo?a=b&c=d" %}
{{ value | urlencode }}

Output: /foo%3Fa%3Db%26c%3Dd

urlencode_strict

Same as urlencode, but also encodes /.

round

Rounds a floating-point number.

Parameters:

method: rounding method.
1. common: round half up (default)
2. ceil: round up
3. floor: round down
precision: number of decimal places. Defaults to 0.

filesizeformat

Converts an integer to a human-readable file size format.

{{ num | filesizeformat }}

date

Converts a timestamp or date to the specified date format.

{{ ts | date }} 
{{ ts | date(format="%Y-%m-%d %H:%M") }}

The timezone parameter can be specified; it defaults to Asia/Chongqing when omitted.

escape

Escapes special characters.

& => &
< => <
> => >
" => "
' => '
/ => /

escape_xml

Escapes XML special characters.

& => &
< => <
> => >
" => "
' => '

safe

By default, content output undergoes HTML special character escaping. The safe filter prevents HTML escaping of the final output.

get

Retrieves a value from an object by key, supporting multi-level access. The default parameter is optional and specifies the default value to return when the key does not exist.

{{ sections | get(key="posts/content", default="default") }}

split

Splits a string into a list using the specified delimiter.

{{ path | split(pat="/") }}

int

Converts a value to an integer. Recognizes prefixes 0b, 0o, 0x.

Parameters:

default: optional. The default value to use on conversion error.
base: optional. The integer base. Valid values: 10, 2, 8, 16.

float

Converts to a floating-point number. The default parameter can specify the default value to use on conversion error.

json_encode

Converts to a standard JSON string. For security reasons, Everkm Publish automatically escapes HTML characters, so you can combine it with safe to disable escaping.

{{ value | json_encode | safe }}

Parameters:

pretty: optional. Outputs a pretty-printed JSON string. Valid values: true or false.

{{ value | json_encode(pretty=true) | safe }}

default

Provides a default value for undefined variables.

Note: only effective for undefined variables. Does not apply to empty strings (""), 0, or false.

I would like to read more {{ "" | default (value="Louise Michel") }}!

Output: I would like to read more !

json

Converts text to a JSON object.

{{ value | json }}

markdown_to_html

Alias: md_to_html. Converts Markdown text to HTML.

{{ value | md_to_html }}

thumbnail

Automatically generates a thumbnail.

Parameters

Key	Meaning	Type	Optional	Notes
wxh	Max width x max height	string	yes	When omitted, falls back to config `cfg.thumbnail.default_dimension`; if also unset, uses the original image. You can specify only height or width, e.g., `400x` (width limited to 400px) or `x300` (height limited to 300px).

Returns

Thumbnail information.

Key	Meaning	Type
url	Thumbnail URL	string
width	Thumbnail width	integer
height	Thumbnail height	integer

object_keys

Gets a list of an object's keys.

Returns

[
    "<key>",
]

object_values

Gets a list of an object's values.

Returns

[
    <value>,
]