Octopus Deploy Documentation

Variable filters

Last updated

By default, bindings are inserted into the output as-is; no consideration is given as to whether the target variable or file is XML, HTML, JSON etc. That is, the target file type is always treated as plain text.

Octopus variable substitutions support filters to correctly encode values for a variety of target file types. These are invoked using the | (pipe) operator.

Given the variable:

Name Value Scope
ProjectName You & I

An the template:

<h3>#{ProjectName | HtmlEscape}</h3>

The result will be:

<h3>You &amp; I</h3>

That is, the ampersand has been encoded correctly for use in an HTML document.

The filters provided by Octopus are for use with trusted input; don't rely on them to sanitize data from potentially malicious sources.

Provided filters

Octopus provides the following filters:

Name Purpose Example input Example output
ToLower Forces values to lowercase Automated Deployment automated deployment
ToUpper Forces values to uppercase Automated Deployment AUTOMATED DEPLOYMENT
ToBase64 Converts values to Base64 (using UTF encoding) Bar QmF6
FromBase64 Converts values from Base64 (using UTF encoding) QmF6 Bar
HtmlEscape Escapes entities for use in HTML content 1 < 2 1 \&lt; 2
XmlEscape Escapes entities for use in XML content 1 < 2 1 \&lt; 2
JsonEscape Escapes data for use in JSON strings He said "Hello!" He said \\"Hello!\\"
MarkdownToHTML Converts Markdown to HTML This \_rocks\_ \<p>This \<em>rocks\</em>\</p>
NowDate Outputs the current date 2016-11-03T08:53:11.0946448
NowDateUtc Outputs the current date in UTC 2016-11-02T23:01:46.9441479Z
Format Applies a format 4.3 $4.30
Replace Replaces a pattern 1;2;3 1, 2, 3
Trim Removes whitespace from the start/end ···Bar··· Bar
Truncate Limits the length of values Octopus Deploy Octopus...
Substring Extracts a range of characters by position Octopus Deploy Deploy
UriEscape Escape a URI string A b:c+d/e A%20b:c+d/e
UriDataEscape Escape a URI data string A b:c+d/e A%20b%3Ac%2Bd%2Fe

NowDate and NowDateUtc

The NowDate and NowDateUtc filters take no variable input but can take an additional optional right-hand-side argument the define the string format (Defaults to ISO-8601 Round-trip format).

MyFormat Variable Filter Expression Output
#{ | NowDate } 2016-11-03T08:53:11.0946448
#{ | NowDateUtc} 2016-11-02T23:01:46.9441479Z
#{ | NowDate "HH dd-MMM-yyyy"} 09 03-Nov-2016
#{ | NowDateUtc zz} +00
dd-MM-yyyy #{ | NowDate #{MyFormat}} 03-Nov-2016

Format

The Format filter introduced in Octopus 3.5 allows for converting of input based on an additionally provided argument that is passed to the .ToString() method.

MyVar Value Filter Expression Output
4.3 #{MyVar | Format C} $4.30
2030/05/22 09:05:00 #{MyVar | Format yyyy} 2030
#{ | NowDate | Format Date MMM} Nov

Replace

The Replace filter introduced in Octopus 2018.8.4 performs a regular expression replace function on the variable. The regular expression should be provided in the .NET Framework format. Double quotes need to be used around any expressions that contain whitespace or special characters. Expressions containing double quotes can not be expressed inline, but can be done via nested variables. If both the search and replace expressions are variables, ensure there is no space between the expressions.

MyVar Value Filter Expression Output
abc #{MyVar | Replace b} ac
abc #{MyVar | Replace b X} aXc
a b c #{MyVar | Replace "a b" X} X c
ab12c3 #{MyVar | Replace "[0-9]+" X} abXcX
abc #{MyVar | Replace "(.)b(.)" "$2X$1" } cXa
abc #{MyVar | Replace #{match}#{replace}} a_c (when match=b and replace=_)
abc #{MyVar | Replace #{match} _} a_c (when match=b)

Trim

The Trim filter introduced in Octopus 2019.8.0 removes any whitespace from the ends of the input. Both ends are trimmed unless an optional argument of start or end is provided.

MyVar Value Filter Expression Output
···Bar··· #{MyVar | Trim} Bar
···Bar··· #{MyVar | Trim start} Bar···
···Bar··· #{MyVar | Trim end} ···Bar

Truncate

The Truncate filter introduced in Octopus 2019.8.0 limits the length of the input. If the input is longer than the length specified by the argument, the rest is replaced with an ellipsis.

MyVar Value Filter Expression Output
Octopus Deploy #{MyVar | Truncate 7} Octopus...
abc #{MyVar | Truncate 7} abc

Substring

The Substring filter introduced in Octopus 2019.8.0 extracts a range of characters from the input and outputs them. If two arguments are supplied, they are interpreted as start and end offsets of the range. If only one argument is supplied, it is interpreted as the end offset of a range starting at 0.

MyVar Value Filter Expression Output
Octopus Deploy #{MyVar | Substring 8 6} Deploy
Octopus Deploy #{MyVar | Substring 7} Octopus
Octopus Deploy #{MyVar | Substring 2 3} top

UriPart

The UriPart filter introduced in Octopus 2019.10.9 parses the input as a URI and extracts a specified part of it. A helpful error will be written to the output if there is an error in the input or the filter expression.

MyVar Value Filter Expression Output
https://octopus.com/docs #{MyVar | UriPart AbsolutePath} /docs
https://octopus.com/docs #{MyVar | UriPart AbsoluteUri} https://octopus.com/docs
https://octopus.com/docs #{MyVar | UriPart Authority} octopus.com
https://octopus.com/docs #{MyVar | UriPart DnsSafeHost} octopus.com
https://octopus.com/docs#filters #{MyVar | UriPart Fragment} #filters
https://octopus.com/docs #{MyVar | UriPart Host} octopus.com
https://octopus.com/docs #{MyVar | UriPart HostAndPort} octopus.com:443
https://octopus.com/docs #{MyVar | UriPart HostNameType} Dns
https://octopus.com/docs #{MyVar | UriPart IsAbsoluteUri} true
https://octopus.com/docs #{MyVar | UriPart IsDefaultPort} true
https://octopus.com/docs #{MyVar | UriPart IsFile} false
https://octopus.com/docs #{MyVar | UriPart IsLoopback} false
https://octopus.com/docs #{MyVar | UriPart IsUnc} false
https://octopus.com/docs #{MyVar | UriPart Path} /docs
https://octopus.com/docs?filter=faq #{MyVar | UriPart PathAndQuery} /docs?filter=faq
https://octopus.com/docs #{MyVar | UriPart Port} 443
https://octopus.com/docs?filter=faq #{MyVar | UriPart Query} ?filter=faq
https://octopus.com/docs #{MyVar | UriPart Scheme} https
https://octopus.com/docs #{MyVar | UriPart SchemeAndServer} https://octopus.com
https://username:password@octopus.com #{MyVar | UriPart UserInfo} username:password

Differences from regular variable bindings

Because of the flexibility provided by the extended syntax, variables that are not defined will result in the source text, e.g. #{UndefinedVar} being echoed rather than an empty string, so that evaluation problems are easier to spot and debug. The if construct can be used to selectively bind to a variable only when it is defined, e.g. to obtain identical "empty" variable functionality as shown in the first example:

Server=#{if DatabaseServer}#{DatabaseServer}#{/if};

JSON parsing

Octostache 2.x (bundled with Octopus 3.5) includes an update to support parsing JSON formatted variables natively, and using their contained properties for variable substitution.

Given the variable:

Name Value Scope
Custom.MyJson {Name: "t-shirt", Description: "I am a shirt", Sizes: [{size: "small", price: 15.00}, {size: "large", price: 20.00}]}
Custom.MyJson.Description Shirts are not shorts.

And the template:

<h1>#{Custom.MyJson[Name]}</h1>
#{Custom.MyJson.Name} - #{Custom.MyJson.Description}
From: #{Custom.MyJson.Sizes[0].price | Format C}
Sizes: #{Custom.MyJson.Sizes}

The result will be:

<h1>t-shirt</h1>
t-shirt - Shirts are not shorts
From: $15.00
Sizes: [{size: "small", price: 15.00}, {size: "large", price: 20.00}]

There are a few things to note here:

  • The Name property is extracted from the JSON using either dot-notation or indexing.
  • Providing an explicit project variable overrides one obtained by walking through the JSON.
  • Arrays can be accessed using standard numerical index notation.
  • Variables can map to a sub-section of the JSON variable.

Repetition over json

Give the variables:

Name Value
MyNumbers [5,2,4]
MyObjects {Cat: {Price: 11.5, Description: "Meow"}, Dog: {Price: 17.5, Description: "Woof"}}

And the template:

Numbers:
#{each number in MyNumbers}
 - #{number}
#{/each}

Objects:
#{each item in MyObjects}
	#{item.Key}: #{item.Value.Price}
#{/each} 

The resulting text will be:

Numbers:
 - 5
 - 2
 - 4
 
Objects:
Cat: 11.5
Dog: 17.5

Learn more

Need support? We're here to help.