1
Using Liquid filters in
API Management
to transform messages
Written by
Sandro Pereira
{ We can say that Liquid filters are like functions in C# code or Functoids in
BizTalk Server maps. Filters change the output of a Liquid object or variable. }
WHITE PAPER
2
Table of Contents
Introduction
........................................................................................................................................ 4
What is a liquid filter? ........................................................................................................................................................................ 5
How to apply transformations inside api management policies? ...................................................................................................... 6
Supported Liquid filters
.................................................................................................................... 6
Abs ..................................................................................................................................................................................................... 7
Append ............................................................................................................................................................................................... 8
AtLeast ............................................................................................................................................................................................... 8
AtMost ............................................................................................................................................................................................... 9
Capitalize .......................................................................................................................................................................................... 10
Ceil ................................................................................................................................................................................................... 10
Compact ........................................................................................................................................................................................... 10
Concat .............................................................................................................................................................................................. 11
Currency ........................................................................................................................................................................................... 12
Date .................................................................................................................................................................................................. 13
Default .............................................................................................................................................................................................. 14
DividedBy ......................................................................................................................................................................................... 14
Downcase ......................................................................................................................................................................................... 15
Escape .............................................................................................................................................................................................. 16
EscapeOnce ...................................................................................................................................................................................... 16
First .................................................................................................................................................................................................. 17
Floor ................................................................................................................................................................................................. 17
H ....................................................................................................................................................................................................... 17
Join ................................................................................................................................................................................................... 18
Last ................................................................................................................................................................................................... 18
Lstrip ................................................................................................................................................................................................ 19
Map .................................................................................................................................................................................................. 19
Minus ............................................................................................................................................................................................... 20
Modulo ............................................................................................................................................................................................. 21
NewlineToBr ..................................................................................................................................................................................... 21
Plus ................................................................................................................................................................................................... 22
Prepend ............................................................................................................................................................................................ 23
Remove ............................................................................................................................................................................................ 23
RemoveFirst ..................................................................................................................................................................................... 24
Replace ............................................................................................................................................................................................. 24
3
ReplaceFirst ...................................................................................................................................................................................... 25
Reverse ............................................................................................................................................................................................. 25
Round ............................................................................................................................................................................................... 26
Rstrip ................................................................................................................................................................................................ 27
Size ................................................................................................................................................................................................... 27
Slice .................................................................................................................................................................................................. 28
Sort ................................................................................................................................................................................................... 29
Split .................................................................................................................................................................................................. 30
Strip .................................................................................................................................................................................................. 31
StripHtml .......................................................................................................................................................................................... 31
StripNewlines ................................................................................................................................................................................... 32
Times ................................................................................................................................................................................................ 32
Truncate ........................................................................................................................................................................................... 33
TruncateWords ................................................................................................................................................................................ 34
Uniq .................................................................................................................................................................................................. 35
Upcase .............................................................................................................................................................................................. 35
UrlDecode ..................................................................................................................................................................................... 36
UrlEncode ......................................................................................................................................................................................... 36
Where .............................................................................................................................................................................................. 37
About the Author ............................................................................................................................ 39
About DevScope ............................................................................................................................. 40
4
Introduction
Liquid is an open-source template language created by
Shopify
and written in Ruby.
It is the backbone of Shopify themes and is used to load dynamic content on
storefronts.
Azure API Management uses the Liquid templating language (
DotLiquid)
to
transform the body of a request or response. This can be effective if you need to
completely reshape the format of your message. That can be accomplished by using
the set-body policy inside inbound, backend, outbound or on-error policies.
For
example
:
<inbound>
<base />
…
<set-body template="liquid">
{
"Header": {
"OrigSystem": "API Management",
"DateRequest": "{{body.MsgDate}}"
},
"InputParameters": {
"MyObject": {
"Reference": "{{body.ExtId}}",
"Type": "{{body.ObjType}}",
"Id": "{{body.Id}}"
}
}
}
</set-body>
</inbound>
DotLiquid
is a deviation from Shopify's original liquid template language, it is a .Net
port of the popular Shopify's Liquid templating language. It is a separate project that
aims to retain the same template syntax as the original, while using .NET coding
conventions where possible. However, they are not entire the same, in some cases
they have different behaviors.
5
Liquid uses a combination of
objects
,
tags
, and
filters
inside template files to display
dynamic content.
Where:
•
Objects
contain the content that Liquid displays on a page. Objects and
variables are displayed when enclosed in double curly braces: {{ and }}.
Hi my name is {{ author.name }}
•
Tags
create the logic and control flow for templates. The curly brace
percentage delimiters {% and %} and the text that they surround do not
produce any visible output when the template is rendered. This lets you assign
variables and create conditions or loops without showing any of the Liquid logic
on the page.
{% if author %}
Hi my name is {{ author.name }}!
{% endif %}
• Filters change the output of a Liquid object or variable. They are used within
double curly braces {{ }} and variable assignment, and are separated by a pipe
character |.
{{ "Sandro" | Append: " Pereira" }}
On this whitepaper we will focus on the
DotLiquid Filters
you can use on API
Management to transform the body of a request or response.
What is a liquid filter?
As mentioned above,
Filters
change the output of a Liquid object or variable. They are
used within double curly braces {{ }} and variable assignment, and are separated by a
pipe character |. They are like functions in C# code or Functoids in BizTalk Server
maps.
If we apply for example the
Append
filter like:
6
{% assign myvariable = "Sandro" %}
{{ myvariable | Append: " Pereira" }}
The end result will be:
Sandro Pereira
We can also apply multiple
filters
on one output, and are applied from left to right.
Like a PowerShell pipeline. A PowerShell pipeline is a series of commands connected
by pipeline operators (|). Each pipeline operator sends the results of the preceding
command to the next command. Filters use the same concept. For
example
:
"Name": "{{ "Sandro Pereira" | Split: " " | Last }}"
The end result here will be:
“Name”: “Pereira”
How to apply transformations inside api management policies?
The
set-body
policy can be configured to use the Liquid templating language to
transform the body of a request or response. This can be effective if you need to
completely reshape the format of your message.
The implementation of Liquid used in the set-body policy is configured in 'C# mode'.
This is particularly important when doing things such as filtering. As an
example
, using
a date filter requires the use of Pascal casing and C# date formatting e.g.:
{{ body.foo.startDateTime| Date: "yyyyMMddTHH:mm:ssZ" }}
In order to correctly bind to an XML body using the Liquid template, use a set-header
policy to set Content-Type to either application/xml, text/xml (or any type ending
with +xml); for a JSON body, it must be application/json, text/json (or any type ending
with +json).
Supported Liquid filters
One of the biggest differences between
DotLiquid
and
Shopify's Liquid
is that
DotLiquid requires Pascal casing for Liquid filter names, for example:
AtLeast
(DotLiquid) instead of
at_least
(Shopify).
7
The following DotLiquid filters are supported in the
set-body
policy.
Abs
This filter returns the absolute value of a number. The filter It will also work on a
string that only contains a number. Otherwise returns NaN. For
example:
{% assign myvariable = "17" %}
{{ myvariable | Abs }}
Result is
17
{% assign myvariable = "17" %}
{{ myvariable | Abs }}
Result is
17
{% assign myvariable = "-4" %} {{ myvariable | Abs }}
Result is
-4
{% assign myvariable = -4 %} {{ myvariable | Abs }}
Result is
-4
{% assign myvariable = "21.15" %} {{ myvariable | Abs }}
Result is
21.15
{% assign myvariable = "21,15" %} {{ myvariable | Abs }}
Result is
NaN
{% assign myvariable = "Test" %} {{ myvariable | Abs }}
Result is
NaN
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
8
"InternalId": "{{body.Id}}",
"ExternalRef": "{{body.ExternalId}}",
"Age": "{{body.Age | Abs }}"
"StaticValue": "Sandro"
}
}
</set-body>
Append
This filter adds a specified string to the end of another string. To do that you need to:
{% assign myvariable = "Sandro" %}
{{ myvariable | Append: " Pereira" }}
Result is
Sandro Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"InternalId": "{{body.Id}}",
"ExternalRef": "{{body.ExternalId}}",
"filename": "{{body.id | Append: '.xml' }}",
"StaticValue": "Sandro"
}
}
</set-body>
AtLeast
This filter limits a number to a minimum value. To do that you need to:
{% 4 | AtLeast: 5 }}
Result is
5
{% 4 | AtLeast: 3 }}
Result is
4
9
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"InternalId": "{{body.Id}}",
"ExternalRef": "{{body.ExternalId}}",
"Evaluation": "{{body.Eval | AtLeast: 1 }}",
"StaticValue": "Sandro"
}
}
</set-body>
AtMost
This filter it is the inverse of AtLeast, it limits a number to a maximum value.
To do that you need to:
{% 4 | AtMost: 5 }}
Result is
4
{% 4 | AtMost: 3 }}
Result is
3
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"InternalId": "{{body.Id}}",
"ExternalRef": "{{body.ExternalId}}",
"Evaluation": "{{body.Eval | AtMost: 9 }}",
"StaticValue": "Sandro"
}
}
</set-body>
10
Capitalize
This filter makes the first character of a string capitalized and converts the remaining
characters to lowercase. To do that you need to:
{% assign myvariable = "Sandro PEREIRA" %}
{{ myvariable | Capitalize }}
Result is
Sandro Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"InternalId": "{{body.Id}}",
"ExternalRef": "{{body.ExternalId}}",
"Name": "{{body.Name | Capitalize }}"
}
}
</set-body>
Ceil
This filter rounds the input up to the nearest whole number. Liquid tries to convert
the input to a number before the filter is applied. To do that you need to:
{% assign myvariable = 1.4 %}
{{ myvariable | Ceil }}
Result is
2
Despite that is the goal of this filter I couldn’t put it working properly on a set-body
policy in API Management. If I apply the same operation inside APIM I get 1.4 as result.
Compact
This filter Removes any nil values from an array. To do that you need to:
{% assign all_categories = site.pages | Map: "category" | Compact %}
11
{% for item in all_categories %}
- {{ item }}
{% endfor %}
Based on
shopify documentation,
in this example, assume the object site.pages
contains all the metadata for a website. Using assign with the map filter creates a
variable that contains only the values of the category properties of everything in the
site.pages object. If we perform a
Map filter
the result will then be:
- Business
- Celebrities
- Lifestyle
- Sports
- Technology
Combined with the
Compact filter
the result then should be like:
- Business
- Celebrities
- Lifestyle
- Sports
- Technology
On the time I was writing this document I couldn’t find a practical sample to set on
a
set-body
policy or any other policy in API Management.
Concat
This filter concatenates (joins together) multiple arrays. The resulting array contains
all the items from the input arrays. To do that you need to:
{% assign fruits = "apples, oranges, peaches" | Split: ", " %}
{% assign vegetables = "carrots, turnips, potatoes" | Split: ", " %}
{% assign everything = fruits | Concat: vegetables %}
{% for item in everything %}
- {{ item }}
{% endfor %}
According to the official documentation, the result should be:
12
- apples
- oranges
- peaches
- carrots
- turnips
- potatoes
Simple sample on a
set-body
policy
<set-body template="liquid">
{% assign fruits = "apples, oranges, peaches" | Split: ", " %}
{% assign vegetables = "carrots, turnips, potatoes" | Split: ", " %}
{% assign everything = fruits | Concat: vegetables %}
{
"OutputMessage": [
{% for item in everything %}
"Item": "{{ item }}"
{% endfor %}
}
}
</set-body>
However, it seems that it shouldn’t work properly in DotLiquid, since on the time I
write this document I’m always getting the following output:
- apples
- oranges
- peaches
Currency
This filter converts the input object into a formatted currency as specified by the
context culture, or languageTag parameter (if provided). To do that you need to:
{% assign myvariable = "2" %}
{{ myvariable | Currency }}
Result is
$2,00
Simple sample on a
set-body
policy
13
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ 2 | Currency }}",
}
}
</set-body>
We can override language for rendering, for example
'fr-FR'
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ 5 | Currency:'fr-FR' }}",
}
}
</set-body>
The result will be: 5,00 €
Date
This filter formats a date using a .NET date format string. Opposite to the date filter
in shopify that uses
strftime
as the format of the timestamp, DotLiquid use a .Net
date format. To do that you need to:
{% assign myvariable = "2022-11-02 14:39" %}
{{ myvariable | Date: "dd-MM-yyyy HH:mm:ss" }}
Result is
02-11-2022 14:39:00
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"InternalId": "{{body.Date | Date: " dd-MM-yyyy HH:mm:ss " }}"
"StaticValue": "Sandro"
}
}
</set-body>
14
Default
This filter sets a default value for any variable with no assigned value. default will
show its value if the input is nil, false, or empty. To do that you need to:
{% assign myvariable = "" %}
{{ myvariable | Default: "Sandro" }}
Result is
Sandro
{% assign myvariable = "Pereira" %}
{{ myvariable | Default: "Sandro" }}
Result is
Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"SystemName": "{{body.System | Default: "APIM" }}"
}
}
</set-body>
DividedBy
This filter divides a number by another number. The result is rounded down to the
nearest integer (that is, the floor) if the divisor is an integer. To do that you need to:
{% assign myvariable = 10 %}
{{ myvariable | DividedBy: 2 }}
Result is
5
{% assign myvariable = 10 %}
{{ myvariable | DividedBy: 3 }}
Result is
3
15
{% assign myvariable = 10 %}
{{ myvariable | DividedBy: 3.2 }}
Result is
3.12499995343387
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Name": "{{ 10 | DividedBy: 2 }}"
}
}
</set-body>
Notice:
the filter doesn’t accept string has input.
Downcase
This filter makes each character in a string lowercase. It has no effect on strings which
are already all lowercase. To do that you need to:
{% assign myvariable = "Sandro Pereira" %}
{{ myvariable | Downcase }}
Result is
sandro pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ "Sandro Pereira" | Downcase }}",
}
}
</set-body>
16
Escape
This filter Escapes HTML chars in a string by replacing characters with escape
sequences (so that the string can be used in a URL, for example). It doesn’t change
strings that don’t have anything to escape. To do that you need to:
{% assign myvariable = "Sandro > Pereira 'Hello'?" %}
{{ myvariable | Escape }}
Result is
Sandro >
;
Pereira 'Hello'?
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ "Sandro > Pereira 'Hello'?" | Escape }}",
}
}
</set-body>
EscapeOnce
This filter escapes HTML chars in a string without changing existing escaped entities.
It doesn’t change strings that don’t have anything to escape. To do that you need to:
{% assign myvariable = "Sandro < Pereira &" %}
{{ myvariable | EscapeOnce }}
Result is
Sandro < Pereira &
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ item.Name | EscapeOnce }}",
}
}
</set-body>
17
First
This filter returns the first item of an array. To do that you need to:
{% assign myvariable = "Sandro Pereira" | Split: " " %}
{{ myvariable | First }}
Result is
Sandro
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": [
"Name": "{{ "Sandro Pereira" | Split: " " | First }}"
]
}
</set-body>
Floor
This filter rounds the input down to the nearest whole number. Liquid tries to convert
the input to a number before the filter is applied. To do that you need to:
{% assign myvariable = 1.4 %}
{{ myvariable | Floor }}
Result is
1
Despite that is the goal of this filter I couldn’t put it working properly on a set-body
policy in API Management. If I apply the same operation inside APIM I get 1.4 as result.
H
This filter escape html chars. This is exactly the same as Escape filter – it is an alias
to the Escape filter. It doesn’t change strings that don’t have anything to escape. To
do that you need to:
18
{% assign myvariable = "Sandro 'A' Pereira" %}
{{ myvariable | H }}
Result is
Sandro 'A' Pereira
Simple sample on a set-body policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ "Sandro 'A' Pereira" | H }}",
}
}
</set-body>
Join
This filter joins elements of the array into a single string using the argument as a
separator. To do that you need to:
{% assign beatles = "John, Paul, George, Ringo" | Split: ", " %}
{{ beatles | Join: " and " }}
Result is
John and Paul and George and Ringo
Simple sample on a
set-body
policy
<set-body template="liquid">
{% assign beatles = "John, Paul, George, Ringo" | Split: ", " %}
{
"OutputMessage": [
"Name": "{{ beatles | Join: " and " }}"
]
}
</set-body>
Last
This filter returns the last item of an array. To do that you need to:
19
{% assign myvariable = "Sandro Pereira" | Split: " " %}
{{ myvariable | Last }}
Result is
Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": [
"Name": "{{ "Sandro Pereira" | Split: " " | Last }}"
]
}
</set-body>
Lstrip
This filter Removes all whitespace (tabs, spaces, and newlines) from the left side of a
string. It does not affect spaces between words. To do that you need to:
{% assign myvariable = " Sandro Pereira !" %}
{{ myvariable | Lstrip }}
Result is
Sandro Pereira !
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Items": "{{ " Sandro Pereira !" | Lstrip }}"
}
}
</set-body>
Map
This filter creates an array of values by extracting the values of a named property
from another object. To do that you need to:
{% assign all_categories = site.pages | Map: "category" %}
20
{% for item in all_categories %}
- {{ item }}
{% endfor %}
Based on
shopify documentation
, in this example, assume the object site.pages
contains all the metadata for a website. Using assign with the map filter creates a
variable that contains only the values of the category properties of everything in the
site.pages object. The result will then be:
- Business
- Celebrities
- Lifestyle
- Sports
- Technology
On the time I was writing this document I couldn’t find a practical sample to set on a
set-body
policy or any other policy in API Management.
Minus
This filter subtracts a number from another number. To do that you need to:
{% assign myvariable = 4 %}
{{ myvariable | Minus: 3 }}
Result is
1
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Name": "{{ 4 | Minus: 3 }}"
}
}
</set-body>
If you provide negative values on the Minus input this operation will be converted to
an addition. For
example
:
21
{% assign myvariable = 4 %}
{{ myvariable | Minus: -3 }}
Result will be
7
.
Notice that, opposite to the Plus filter the Minus do not allow that the input to be a
string.
Modulo
This filter returns the remainder of a division operation. To do that you need to:
{% assign myvariable = 3 %}
{{ myvariable | Modulo: 2 }}
Result is
1
{% assign myvariable = 183.357 %}
{{ myvariable | Modulo: 12 }}
Result is
3.357
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Name": "{{ 3 | Modulo: 2 }}"
}
}
</set-body>
Notice:
the filter doesn’t accept string has input.
NewlineToBr
This filter inserts an HTML line break (<br />) in front of each newline (\n) in a string.
To do that you need to:
{% capture string_with_newlines %}Sandro
22
Pereira{% endcapture %}
{{ string_with_newlines | NewlineToBr }}
Result is:
Sandro <br />
Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{% capture string_with_newlines %}Sandro
Pereira{% endcapture %}
{
"OutputMessage": {
"Items": "{{ string_with_newlines | NewlineToBr }}"
}
}
</set-body>
Plus
This filter adds a number to another number. If you provide a string this will converts
as a concatenation operation. To do that you need to:
{% assign myvariable = 4 %}
{{ myvariable | Plus: 4 }}
Result is
8
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Name": "{{ 4 | Plus: 4 }}"
}
}
</set-body>
23
Once, again if you provide a string as input that will perform a concatenation. For
example
:
{% assign myvariable = "4" %}
{{ myvariable | Plus: 4 }}
Result will be
44
Prepend
This filter adds the specified string to the beginning of another string. To do that you
need to:
{% assign myvariable = "Sandro Pereira" %}
{{ myvariable | Prepend: "person: " }}
Result is person:
Sandro Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"InternalId": "{{body.Id | Prepend: "entity: " }}"
}
}
</set-body>
Remove
This filter removes every occurrence of the specified substring from a string. To do
that you need to:
{% assign myvariable = "Sandro \Pereira\" %}
{{ myvariable | Remove: "\" }}
Result is
Sandro Pereira
Simple sample on a
set-body
policy
24
<set-body template="liquid">
{
"OutputMessage": {
"Name": "{{ result.Address | Remove: "\" }}"
}
}
</set-body>
RemoveFirst
This filter removes only the first occurrence of the specified substring from a string.
To do that y ou need to:
{% assign myvariable = "Sandro !Pereira!" %}
{{ myvariable | RemoveFirst: "!" }}
Result is
Sandro Pereira!
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Name": "{{ result.Address | RemoveFirst: "!" }}"
}
}
</set-body>
Replace
This filter replaces every occurrence of the first argument in a string with the second
argument. To do that you need to:
{% assign myvariable = "Sandro \ Pereira" %}
{{ myvariable | Replace: '\\', '\\' }}
Result is
Sandro \\ Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
25
{
"OutputMessage": {
"Name": "{{ result.Address | Replace: '\\', '\\' }}"
}
}
</set-body>
ReplaceFirst
This filter replaces only the first occurrence of the first argument in a string with the
second argument. To do that you need to:
{% assign myvariable = "Sandro !Pereira!" %}
{{ myvariable | ReplaceFirst: '!', '' }}
Result is
Sandro Pereira!
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Name": "{{ result.Address | ReplaceFirst: '!', '' }}"
}
}
</set-body>
Reverse
This filter reverses the order of the items in an array. reverse cannot reverse a string.
To do that you need to:
{% assign my_array = "John, Paul, George, Ringo" | Split: ", " %}
{{ my_array | Reverse }}
Result is:
JohnPaulGeorgeRingo
{% assign my_array = "John, Paul, George, Ringo" | Split: ", " %}
{{ my_array | Reverse | Join: " and " }}
Result is: John and Paul and George and Ringo
26
Simple sample on a
set-body
policy
<set-body template="liquid">
{% assign my_array = "John, Paul, George, Ringo" | Split: ", " %}
{
"OutputMessage": {
"Items": "{{ my_array | Reverse | Join: " and " }}"
}
}
</set-body>
Round
This filter rounds a number to the nearest integer or, if a number is passed as an
argument, to that number of decimal places. To do that you need to:
{% assign myvariable = 1.2 %}
{{ myvariable | Round }}
Result is
1
{% assign myvariable = 1.2 %}
{{ myvariable | Round: 2 }}
Result is
1.2
{% assign myvariable = 1.212 %}
{{ myvariable | Round: 2 }}
Result is
1.21
{% assign myvariable = 1,312 %}
{{ myvariable | Round: 2 }}
Result is
1312
{% assign myvariable = "1,312" %}
{{ myvariable | Round: 2 }}
Result is
1.31
Simple sample on a
set-body
policy
27
<set-body template="liquid">
{
"OutputMessage": {
"UnitPrice": "{{body.Price | Round: 2 }}" }
}
</set-body>
Rstrip
This filter Strip all trailing (from the right side) whitespace (tabs, spaces, and
newlines) from input. It does not affect spaces between words. To do that you need
to:
{% assign myvariable = " Sandro Pereira " %}
{{ myvariable | Rstrip }}
Result is
“ Sandro Pereira”
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": [
"Name": "{{ " Sandro Pereira " | Rstrip }}"
]
}
</set-body>
Size
This filter returns the size of an array or of a string. To do that you need to:
{% assign myvariable = "Sandro" %}
{{ myvariable | Size }}
Result is:
6
Simple sample on a
set-body
policy
<set-body template="liquid">
{
28
"OutputMessage": {
"Money": "{{ "Sandro" | Size }}",
}
}
</set-body>
If we work with arrays, then for
example
:
<set-body template="liquid">
{% assign my_array = "apples, oranges, peaches, plums" | Split: ", " %}
{
"OutputMessage": {
"Money": "{{ my_array | Size }}",
}
}
</set-body>
The result will be
4
.
Slice
This filter returns a substring of one character or series of array items beginning at
the index specified by the first argument. An optional second argument specifies the
length of the substring or number of array items to be returned. To do that you need
to:
{% assign myvariable = "Sandro Pereira" %}
{{ myvariable | Slice: 0 }}
Result is
S
Simple sample on a
set-body
policy
<set-body template="liquid">
{% assign my_array = "apples, oranges, peaches, plums" | Split: ", " %}
{
"OutputMessage": {
"Money": "{{ "Sandro Pereira" | Slice: 0 }}",
}
}
</set-body>
29
If Slice is set to 1 that the result will be
a
.
We can also add a second parameter to specify the length of the substring, let’s say:
{{ myvariable | Slice: 0, 5 }}
The result then will be:
Sandro
Negative values on the first input will count back from the end of the string/array.
{{ myvariable | Slice: -3 }}
The result then will be:
i
Sort
This filter sorts items in an array. Opposite to the default
sort
filter in shopify this
is
not
a sort in case-sensitive order. DotLiquid Sort filter in case-insensitive to do that
you need to:
{% assign beatles = "John, Paul, George, Ringo" | Split: ", " | Sort %}
{% for member in beatles %}
{{ member }}
{% endfor %}
Result is:
- George
- John
- Paul
- Ringo
Simple sample on a
set-body
policy:
<set-body template="liquid">
{% assign beatles = "John, Paul, George, Ringo" | Split: ", " | Sort %}
{{ beatles}}
{
"OutputMessage": [
{% for member in beatles %}
30
"Member": "{{ member }}"{% if forloop.last != true %},{% endif %}
{% endfor %}
]
}
</set-body>
Split
This filter split input string into an array of substrings separated by given pattern. To
do that you need to:
{% assign beatles = "John, Paul, George, Ringo" | Split: ", " %}
{% for member in beatles %}
{{ member }}
{% endfor %}
Result would be:
- John
- Paul
- George
- Ringo
Simple sample on a
set-body
policy
<set-body template="liquid">
{% assign beatles = "John, Paul, George, Ringo" | Split: ", " %}
{
"OutputMessage": [
{% for member in beatles %}
"Member": "{{ member }}"{% if forloop.last != true %},{% endif %}
{% endfor %}
]
}
</set-body>
31
Strip
This filter removes all whitespace (tabs, spaces, and newlines) from both the left and
right sides of a string. It does not affect spaces between words. To do that you need
to:
{% assign myvariable = " Sandro Pereira " %}
{{ myvariable | Strip }}
Result is
Sandro Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": [
"Name": "{{ " Sandro Pereira " | Strip }}"
]
}
</set-body>
StripHtml
This filter removes any
HTML tags
from a string. To do that you need to:
{% assign myvariable = "Sandro <strong>Pereira</strong>" %}
{{ myvariable | StripHtml }}
Result is
Sandro Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": [
"Name": "{{ "Sandro <strong>Pereira</strong>" | StripHtml }}"
]
}
</set-body>
32
StripNewlines
This filter removes any newline characters (line breaks) from a string. To do that you
need to:
{% capture string_with_newlines %}Sandro
Pereira{% endcapture %}
{{ string_with_newlines | StripNewlines }}
Result is
Sandro Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{% capture string_with_newlines %}Sandro
Pereira{% endcapture %}
{
"OutputMessage": [
"Name": "{{ string_with_newlines | StripNewlines }}"
]
}
</set-body>
Notice:
it does not remove <br />. For example, if the input is:
{% capture string_with_newlines %}Sandro<br /> Pereira{% endcapture %}
{{ string_with_newlines | StripNewlines }}
The result will still be:
Sandro<br /> Pereira
Times
Do not get fooled by the name of this filter, it is not to perform operation in datetime
or time (clock), this is a mathematic operation. This filter multiplies a number by
another number. To do that you need to:
{% assign myvariable = 4 %}
{{ myvariable | Times: 2 }}
Result is
8
33
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"TotalValue": "{{body.Quantity | Times: body.UnitPrice }}"
}
}
</set-body>
DotLiquid Times filter also allows that the input to be a string. On that case it will
repeat the input the certain amount of times you specify on the multiple input
{% assign myvariable = "Sandro" %}
{{ myvariable | Times: 2 }}
Result is
SandroSandro
Truncate
This filter shortens a string down (truncates) to the number of characters passed as
an argument. If the specified number of characters is less than the length of the
string, an ellipsis (…) is appended to the string and is included in the character count.
To do that you need to:
{% assign myvariable = "Sandro Pereira" %}
{{ myvariable | Truncate: 6 }}
Result is
Sandro...
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ "Sandro Pereira" | Truncate: 40 }}",
}
}
</set-body>
34
If we set for
example
Truncate
: 40 then the result would be only
Sandro Pereira
Optional we can setup a suffix to append when string is truncated. The defaults are
the ellipsis(...). For
example
:
{% assign myvariable = "Sandro Pereira" %}
{{ myvariable | Truncate: 7, "+" }}
The result then will be
Sandro+
TruncateWords
This filter shortens a string down to the number of words passed as an argument. If
the specified number of words is less than the number of words in the string, an ellipsis
(…) is appended to the string. To do that you need to:
{% assign myvariable = "Sandro Augusto Sousa Pereira" %}
{{ myvariable | TruncateWords: 2 }}
Result is
Sandro Augusto...
Simple sample on
a set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ "Sandro Augusto Sousa Pereira" | TruncateWords: 2 }}",
}
}
</set-body>
If we set for example
Truncate
: 40 then the result would be only
Sandro Augusto
Sousa Pereira
Optional we can setup a suffix to append when string is truncated. The defaults is the
ellipsis(...). For
example
:
{% assign myvariable = "Sandro Pereira" %}
{{ myvariable | Truncate: 2, "---" }}
35
The result then will be
Sandro Augusto---
Uniq
This filter removes any duplicate items in an array. To do that you need to:
{% assign my_array = "Sandro, Pereira, Sandro, Pereira" | Split: ", " %}
{{ my_array | Uniq | Join: ", " }}
Result is
Sandro, Pereira
Simple sample on a
set-body
policy
<set-body template="liquid">
{% assign my_array = "Sandro, Pereira, Sandro, Pereira" | Split: ", " %}
{
"OutputMessage": {
"Items": "{{ my_array | Uniq | Join: ", " }}"
}
}
</set-body>
Upcase
This filter makes each character in a string uppercase. It has no effect on strings which
are already all uppercase. To do that you need to:
{% assign myvariable = "Sandro Pereira" %}
{{ myvariable | Upcase }}
Result is
SANDRO PEREIRA
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ "Sandro Pereira" | Upcase }}",
}
}
</set-body>
36
UrlDecode
This filter decodes a string that has been encoded as a URL or by UrlEncode filter. To
do that you need to:
{% assign myvariable = "sandro.pereira%40devscope.net" %}
{{ myvariable | UrlDecode }}
Result is
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{context.Request.OriginalUrl.Query.Name | UrlDecode }}",
}
}
</set-body>
UrlEncode
This filter converts any URL-unsafe characters in a string into percent-encoded
characters. To do that you need to:
{{ myvariable | UrlEncode }}
Result is
sandro.pereira%40devscope.net
Simple sample on a
set-body
policy
<set-body template="liquid">
{
"OutputMessage": {
"Money": "{{ "[email protected]" | UrlEncode }}",
}
}
</set-body>
37
For me, this filter makes more sense to use not inside bodies but when we are
extracting a value from a message and add it to a URL to do for example a Get HTTP
call.
Another example is, if the value is
sandro:pereira/net
the result of the UrlEncode
filter will be sandro%3Apereira%2Fnet
Where
This filter creates an array including only the objects with a given property value, or
any truthy value by default. To do that you need to:
All products:
{% for product in products %}
- {{ product.title }}
{% endfor %}
{% assign kitchen_products = products | where: "type", "kitchen" %}
Kitchen products:
{% for product in kitchen_products %}
- {{ product.title }}
{% endfor %}
Based on
shopify documentation,
in this example, assume you have a list of products,
and you want to show your kitchen products separately. Using where, you can create
an array containing only the products that have a "type" of "kitchen". The result will
then be:
All products:
- Vacuum
- Spatula
- Television
- Garlic press
Kitchen products:
- Spatula
- Garlic press
38
On the time I was writing this document I couldn’t find a practical sample to set on
a
set-body
policy or any other policy in API Management.
39
About the Author
Written by
Sandro Pereira
Azure MVP & MCTS BizTalk
Server 2010
twitter.com
/sandro_asp
linkedin.com
/in/sandropereira
github.com
/sandroasp
Sandro is very active in the BizTalk
community as
blogger
, member and
moderator on the MSDN BizTalk Server
Forums, TechNet Wiki author, Code
Gallery and GitHub contributor,
member of several online communities,
guest author at BizTalk360 and
Serverless360, public speaker and
technical reviewer of several BizTalk
and Azure books and whitepapers, all
focused on Integration. He is also the
author of the book
BizTalk Mapping
Patterns & Best Practices
.
Sandro Pereira
lives in Portugal and is
currently the Head of Enterprise
Integration at
DevScope
. In the past
years, he has been working on
implementing Integration scenarios
both on-premises and cloud for various
clients, each with different scenarios
from a technical point of view, size, and
criticality, using Microsoft Azure (API
Management, Logic Apps, Service Bus,
Event Hubs, PowerApps, Power
Automate, …), Microsoft BizTalk Server
and different technologies like AS2,
EDI, RosettaNet, SAP, TIBCO and many
others.
He has been awarded the Microsoft Most Valuable Professional (MVP) since January
2011, for his contributions to the world-wide
BizTalk Server community
and
Microsoft
Azure com
. He currently holds MCTS: BizTalk Server 2006 and BizTalk Server 2010
certifications.
40
About DevScope
Rua de Passos Manuel 223, 3º
4000-385 Porto
T. 22 375 1350
info@devscope.net
devscope.net
DevScope
specializes in giving organizations
the tools and knowledge they need to be
competitive. We are one of the most
distinguished Microsoft partners in Portugal,
one of the few companies in the country with
two advanced specializations and 9 Gold
certifications in different technological areas.
We are pioneers and always work with the
latest technology to provide our customers
and partners with the most advanced
solutions. For almost 20 years, we have
developed and implemented solutions in and
outside Portugal in the most varied areas of
activity, from retail to health, through real
estate or the public sector, producing lasting
results.
Solutions
§ Power Platform
§ Portals – Office 365 & SharePoint
§ Web and App Development
§ AI Machine Learning
§ Business Intelligent
§ Enterprise Integration
§ Cloud & DevOps
§ Training & Education
Products
§ PowerBI Tiles Pro
§ PowerBI Robots
§ PowerBI Portal
§ PowerBI Data Portal
§ SmartDocumentor Cloud
2
Rua de Passos Manuel 223, 3º
4000-385 Porto | T. 22 375 1350
info@devscope.net
devscope.net
