Introduction to Nunjucks
Nunjucks is a sophisticated templating engine for JavaScript. It lets you insert dynamic content in any text through the use of templates. A template contains variables and/or expressions, which get replaced with values when a template is rendered; and tags, which control the logic of the template. See here for an overview of the templating features available in Nunjucks.
Nunjucks in JMWE for JIRA Cloud
Nunjucks in JMWE for JIRA Cloud is used to insert information while
- Setting a field value by a post-function
- Commenting an issue by a post-function
- Conditionally executing a post-function
You can insert issue and transition information into the value using the templating features available in Nunjucks. Some basic templating features are described in this document, and more are documented on the Nunjucks website.
Templating features in Nunjucks
- Nunjucks template editor and tester
- Variables used in Nunjucks templates — A variable looks up a value from the template context. This documents details on the variables available in JMWE and how to create custom variables.
- Built in Nunjucks Filters — Filters are essentially functions that can be applied to variables. This document details some of the Nunjucks built-in filters.
- Custom Nunjucks filters — Filters are essentially functions that can be applied to variables. Filters are called with a pipe operator (|) and can take arguments. This document details custom Nunjucks filters created for JMWE.
- Tags and Expressions — Tags are special blocks that perform operations on sections of the template and Expressions are literal expressions similar to those in javascript.
- Accessing the details of an issue or a transition in Nunjucks — This document explains how to access the details of issue and transition objects, such as those available through the issue and transition variables. To see an example of the structure of an issue go to <base_URL_of_Jira>/rest/api/latest/issue/{issueKey}. The fields displayed through this REST API actually depend on the fields set on the issue.
- Conditional execution — Post functions are provided with an option to control their execution. You need to input a Nunjucks template in the Condition field, and based on the result of that expression, the post-function will either be executed or skipped.
- Shared Nunjucks Templates
On this page:
Variables
A variable looks up a value from the template context. If you want to insert the value of a variable in your template, you can use the following syntax: {{ myVar }}
. This looks up for the myVar
variable from the context and displays it. Variable names can have dots in them which look up properties, just like in javascript.
Variables available in JMWE
JMWE makes the issue, transition, linkedIssue, parentIssue, now
and currentUser
variables available to templates. You can access their properties using "." or "[ ]". For example, you can access the current issue key using {{issue.key}}
.
issue variable
The issue
variable is used to insert data of the issue being transitioned. You can access the issue data by looking up at its properties.
For example:
{{issue.fields.labels}}
returns an array of label values, e.g. [ "1", "2" ]
{{issue.fields.reporter.name}}
returns the username of the reporter, e.g. carter
transition variable
The transition
variable is used to insert information of the transition being executed.
For example:
{{transition.transitionName}}
returns the name of the transition, e.g. Start Progress
{{transition.to_status}}
returns the status of the transition, e.g. In Progress
linkedIssue variable
The linkedIssue
variable, which is only available from post-functions that work on linked issues, is used to insert data of the linked issue being processed by the post-function.
For example:
{{linkedIssue.fields.description}}
returns the description of the linked issue being processed.
parentIssue variable
The parentIssue
variable, which is only available from post-functions that work on the parent issue, is used to insert data of the parent issue being processed by the post-function.
For example:
{{parentIssue.fields.priority.name}}
returns the priority of the parent issue being processed.
currentUser variable
The currentUser
variable is used to insert information about the current user, i.e. the user triggering the transition. Only two properties of the current user are available: key and name.
For example:
{{currentUser.name}}
returns the name of the user triggering the transition, e.g. carter
{{currentUser.key}}
returns the key of the user triggering the transition, e.g. carter001
now variable
The now
variable is used to insert the current date and time. This is useful to save a transition's execution date/time in a custom field.
For example:
{{
now}}
returns the current date and time, e.g. 2016-09-30T13:57:23.608Z
User-defined variables
In addition to the above variables, you can also create your own variables within the template using the set Nunjucks tag.
For example:
{% set x = "High" %}
sets the value of the variable x to High. You can also set the variable to an object. For example: {% set assignee = issue.fields.assignee %}
Tags
Tags are special blocks that perform operations on sections of the template. Nunjucks comes with several built-in tags, such as:
set
The set
tag creates or modifies a variable.
For example:
{% set comments = issue.fields.comment.comments %}
sets the comments variable with all the comment objects of the issue.
if
The if
tag tests a condition.
For example:
{% if issue.fields.issuetype.name == "Task"} This is a task {% endif %}
returns This is a task
if and only if the issue type is "Task".
for
The for
tag iterates over an array of values or objects.
For example:
{% set comments = issue.fields.comment.comments %} {% for comment in comments %} {{ comment.body }} {% endfor %}
iterates over the comments variable and displays each comment body.
You might want to look here for some more built-in tags in Nunjucks.
Filters
Filters are essentially functions that can be applied to variables. They are called with a pipe operator (|) and can take arguments. Some examples:
dump
The dump
filter dumps an object as a JSON string into the template.
For example:
{{ issue.fields.reporter | dump(2) }}
dumps the Reporter user object in "pretty" JSON format, using 2 spaces as indentation.
{{ issue.fields.fixVersions | dump }}
dumps the array of Fix Version/s of the issue in un-prettyfied JSON format.
first
The first
filter gets the first value/object in the array.
For example:
{{ issue.fields.fixVersions | first }}
returns the first Fix Version/s object of the issue.
{{ issue.fields.labels | first }}
returns the first label of the issue.
last
The last
filter gets the last value/object in the array.
For example:
{{ issue.fields.components | last }}
returns the last component object of the issue.
{{ issue.fields.labels | last }}
returns the last label of the issue.
join
The join
filter returns a string which is a concatenation of strings.
For example:
{{ issue.fields.fixVersions | join("," , "name") }}
joins the names of the Fix Version/s, separated by commas. For example: 1,1.0,2.0
dateadd
This is a custom Nunjucks filter that adds (or substracts) hours, days, weeks or months from a date. Its syntax is dateadd(<number>,<units>) where :
- <number> is the number of units to add to the date (can be negative)
- <units> is one of "days", "hours", "weeks" or "months" (or their equivalent: "d", "h", "w", "m")
For example:
{% set duedate = issue.fields.created | dateadd(2,"w") %}
sets the duedate
variable to two weeks after the creation date of the issue.
date
This is a custom Nunjucks filter that offers rich date manipulation and formatting features. For more information, see here.
linkedIssues
linkedIssues
is a custom Nunjucks filter that returns an array of the issues linked to the issue through a specified issue link type name.
- If the link type is not specified the filter returns all linked issues except epic, parentIssue, stories and subtasks of the issue.
- If the specified link type is invalid, an error is logged.
You can access all the fields of a linked issue, similar to the issue object.
For example:
{{ issue | linkedIssues }}
returns the array of linked issues.
{{ issue | linkedIssues | last }}
returns the last linked issue.
{{ issue | linkedIssues('blocks') }}
returns an array of issues linked to the current issue with 'blocks' link type.
To get the status of the first issue that is blocked by the current issue: {{ issue | linkedIssue('blocks') | first | field("fields.status.name") }}.
See below for information on field filter.
epic
epic
is a custom Nunjucks filter that returns the Epic of the issue. You can access all the fields of an Epic, similar to the issue object.
For example:
{{ issue | epic }}
returns the Epic of the issue
To get the name of the current issue's Epic: {{ issue | epic | field("fields['Epic Name'].name") }}.
See below for information on field filter.
stories
stories
is a custom Nunjucks filter that returns an array of stories associated with the issue (which should be an Epic). You can access all the fields of a Story, similar to the issue object.
For example:
{{ issue | stories }}
returns an array of stories of the Epic
Description of the last story associated to the Epic: {{ issue | stories | last | field("fields.description") }}.
See below for information on field filter.
parentIssue
parentIssue
is a custom Nunjucks filter that returns the Parent of the issue. You can access all the fields of the parent issue, similar to the issue object.
For example:
{{ issue | parentIssue }}
returns the parent of the issue
To get the Epic link of the current issue's parent: {{ issue | parentIssue | field("fields['Epic Link']") }}.
See below for information on field filter.
subtasks
subtasks
is a custom Nunjucks filter that returns an array of subtasks associated with the current issue. You can access all the fields of a subtask, similar to the issue object.
For example:
{{ issue | subtasks }}
returns an array of subtasks of the issue
The number of subtasks for an issue:
{% set subtasks = issue | subtasks %} {% set count = 0 %} {% for subtask in subtasks %} {% set count = count + 1 %} {%endfor%} {{ count }}
field
field is a custom Nunjucks filter that returns the value of a field of an object. It applies to an object and takes the field name as a parameter. The field name can also be a path (using dot notation). This is useful to access the field of the result of another filter, instead of having to use an intermediate variable.
For example:
{{ issue.fields.versions | first | field("name") }}
returns the name of the first Affects Version/s.
{{ issue | epic | field("fields.reporter.name") }}
returns the username of the reporter of the Epic of the issue.
{{ issue | parentIssue | field("fields['Original Estimate']") }}
returns the original estimate of the issues' parent issue.
sprints
sprints
is a custom Nunjucks filter that returns the sprints of an issue or a board. It applies to an issue object or a board ID. For an issue, it uses the first scrum board to which the issue's project belongs. It takes an optional state or a list of comma-separated states as a parameter. See below the structure:
[ { "id": 37, "self": "http://www.example.com/jira/rest/agile/1.0/sprint/23", "state": "closed", "name": "sprint 1", "startDate": "2015-04-11T15:22:00.000+10:00", "endDate": "2015-04-20T01:22:00.000+10:00", "completeDate": "2015-04-20T11:04:00.000+10:00", "originBoardId": 5 }, { "id": 72, "self": "http://www.example.com/jira/rest/agile/1.0/sprint/73", "state": "future", "name": "sprint 2" } ]
For example:
{{ issue | sprints }}
returns a list of sprints. See below the structure:
{{ issue | sprints | join("," , "name") }}
returns the names of the Sprints, separated by commas.
{{ issue | sprints("active") | first | field("id") }}
returns the currently active sprint ID.
isInGroup
The isInGroup
filter is a custom Nunjucks filter that returns true if the user is in the specified group (passed as a parameter to the filter). The user, provided as input to the filter, can be either a username or a user object.
For example:
{{ currentUser | isInGroup("jira-administrators") }}
returns true if the current user is in the "jira-administrators" group.
{{ issue.fields.assignee | isInGroup("jira-servicedesk-users") }}
returns true if the assignee of the issue is in the "jira-servicedesk-users" group.
isInRole
The isInRole
filter is a custom Nunjucks filter that returns true if the user is in the named role (passed as a parameter to the filter). The user, provided as input to the filter, can be either a username or a user object. Expected parameters are:
isInRole(roleName)
: returns true if the user is in the named project role of the project of the current issueisInRole(roleName, projectKey)
: returns true if the user is in the named project role of the project whose key is the specified projectKeyisInRole(roleName, issueObject)
: returns true if the user is in the named project role of the project of the given issue object
For example:
{{ currentUser | isInRole("Developers") }}
returns true if the current user is in the "Developers" project role.
{{ issue.fields.reporter | isInRole("Developers","ARM") }}
returns true if the current user is in the "Developers" project role of the project whose key is "ARM"
{{ currentUser | isInRole("Developers",linkedIssue) }}
returns true if the current user is in the "Developers" project role of the project of the first issue linked to the current issue with 'blocks' link type.
userProperty(<property key>)
The userProperty
filter is a custom Nunjucks filter that returns the value of the user property key (passed as a parameter to the filter) from the user entity properties that are set on the User properties editor page. The user, provided as input to the filter, can be either a username or a user object. If the requested user property cannot be found, the filter returns undefined
(which is equivalent to an empty string).
For example:
{{ currentUser | userProperty("Location") }}
returns the value of the key Location
{{ issue.fields.assignee | userProperty("State") }}
returns the value of the key State
You will find a lot more Nunjucks built-in filters here.
Expressions
You can use many types of literal expressions similar to those in javascript, such as:
Mathematical expressions
Nunjucks allows you to do simple calculations on numbers.
For example:
{{ issue.fields.Field1 + issue.fields.Field2 }}
outputs the sum of two custom field values, where Field1
and Field2
are the custom field names.
{{ OriginalEstimate*2 }}
doubles the original estimate of the issue.
Comparisons
Nunjucks allows you to compare two values or objects.
For example:
{{ issue.fields.issuetype.name == "Task" }}
compares both values.
If
Nunjucks allows you to use if as an inline expression.
For example:
{{ "true" if var else "false" }}
outputs the string "true" if the variable var is defined, else it outputs "false".
You might want to look here for some more built-in expressions in Nunjucks.
You might also want to look at Accessing the details of an issue or a transition in Nunjucks to know how to access the details of an issue or a transition.
See here for more templating features available in Nunjucks. You might also want to refer here for use cases with Nunjucks annotations.