Are there any liquid shorthands? For example I'm trying to express this in a more concise way:
{% if job.offsite %}}
{{job.offsite}}
{{% else %}}
{{ job.url }}
{% endif %}
For this particular example, you could write:
{{ job.offsite | default: job.url }}
The value provided to the default filter will be used if the left side of the expression is false or nil.
Related
I have a use case where I would like to define the name of a macro and then apply it to one column.
A simplified example could be as follows. I have two macros defined that I want to call dynamically in my model (both take one column as an input):
cast_to_string
convert_empty_string_to_null_value
Now, I want to call them dynamically. See the example below
{%- set macro_names = ["cast_to_string", "convert_empty_string_to_null_value"] -%}
select
{% for macro_name in macro_names %}
-- this should dynamically be evaluated to `{{ cast_to_string(my_column) }}`
-- and `{{ convert_empty_string_to_null_value(my_column) }}`
{{ macro_name(my_column) }}
{% endfor %}
from my_model
However, this will throw an error saying that a string is not callable.
I also tried using {% raw %} {{ {% endraw %} to escape brackets, but that didn’t work either.
So, my question is, if there is a way to dynamically call macros in jinja/dbt?
I think it should work if you remove the quotes :
{%- set macro_names = [cast_to_string, convert_empty_string_to_null_value] -%}
So that jinja doesn't interpret it as string and you can use it as a Callable
I achieve it using this example :
{%- set macro_names = [print_lower, print_upper] -%}
{% for macro_name in macro_names %}
{{ macro_name("test") }}
{% endfor %}
and
{% macro print_lower(string) %}
{{ print(string|lower) }}
{% endmacro %}
{% macro print_upper(string) %}
{{ print(string|upper) }}
{% endmacro %}
I would like to organize a page based on the number of pages that pass a filter.
I have tried to append truthy pages to a collection but it doesn't work.
{% assign homepage_posts = [] %}
{% for my_page in site.pages %}
{% if my_page.homepage %}
{% assign homepage_posts = homepage_posts | concat: [my_page] %}
{% endif %}
{% endfor %}
<h1>size{{homepage_posts.size}}</h1>
<h1>{{homepage_posts}}</h1>
This is not working. Does concat only work with strings?
Jekyll will use Liquid 4 soon. But, for now, no concat.
In your case you can :
Create an empty array (bracket notation doesn't work in liquid) : {% assign homepage_posts = "" | split:"/" %}
{{ homepage_posts | inspect }} --> output : []
And push elements in it :
{% for my_page in site.pages %}
{% if my_page.homepage %}
{% assign homepage_posts = homepage_posts | push: mypage %}
{% endif %}
{% endfor %}
{{ homepage_posts | inspect }}
concat filter only works with arrays and will be available in Jekyll when it upgrades to Liquid 4.*:
concat
Concatenates (combines) an array with another array. The resulting
array contains all the elements of the original arrays. concat will
not remove duplicate entries from the concatenated array unless you
also use the uniq filter.
To filter pages containing a specific attribute (in this case homepage: true) you can use a where filter.
Having a page with front matter:
---
homepage: true
---
Then you can have the pages with the homepage: true attribute like:
{% assign homepages = site.pages | where:"homepage","true" %}
I want to render the “Tags:” label only if the post has actual tags. When I write
{{post.tags | size}}
I get the number of tags. However, if I put it in an {% if %} condition:
{% if post.tags | size != '0' %}
it always yields true. I worked around this problem with
{% capture tagsize %}{{post.tags | size}}{% endcapture %}
{% if tagsize != '0' %}
but it seems very ugly. Is there a better way to do this?
Note: I use GitHub Pages, so using a plugin – other than being an overkill – is not an option. My Jekyll version is 2.0.4 as specified here as of date.
By default {{ post.tags }} == empty array.
As we cannot do {% if post.tags != [] %}, we just add array: [] in _config.yml.
We can now do :
{% if post.tags != site.array %}
Do something
{% endif %}
tag size returns an integer and not a string so you should compare against 0 and not '0'
{% if page.tags.size != 0 %}
<!-- some code to render tags -->
{% endif %}
I would like to cocatenate a group of ips into a string.
example ip1:2181,ip2:2181,ip3:2181,etc
{% for host in groups['zookeeper'] %}
{{ hostvars[host]['ansible_eth0']['ipv4']['address'] }}
{% endfor %}
I have the above code, but can't seem to quite figure out how to concatenate into a string.
searching for "Jinja2 concatenate" doesn't give me the info I need.
Updated this answer, because I think I misunderstood your question.
If you want to concatenate the IP's of each host with some string, you can work with the loop controls, to check if you're in the last iteration:
{% for host in groups['zookeeper'] -%}
{{ hostvars[host]['ansible_eth0']['ipv4']['address'] }}
{%- if not loop.last %}, {% endif -%}
{%- endfor %}
Old answer:
The word you're looking for is join:
{{ hostvars[host]['ansible_eth0']['ipv4']['address'] | join(", ") }}
You can use the 'extract' filter for this (provided you use ansible>=2.1):
{{ groups['zookeeper'] | map('extract', hostvars, ['ansible_eth0', 'ipv4', 'address']) | join(',') }}
More info:
http://docs.ansible.com/ansible/playbooks_filters.html#extracting-values-from-containers
Found a similar solution at https://adamj.eu/tech/2014/10/02/merging-groups-and-hostvars-in-ansible-variables/ .
I did a set_fact using a groups variable as suggested in the post:
- hosts: all
connection: local
tasks:
- set_fact:
fqdn_list: |
{% set comma = joiner(",") %}
{% for item in play_hosts -%}
{{ comma() }}{{ hostvars[item].ansible_default_ipv4.address }}
{%- endfor %}
This relies on joiner, which has the advantage of not having to worry about the last loop conditional. Then with set_fact I can make use of the new string in later tasks.
Converting from Django, I'm used to doing something like this:
{% if not var1 %} {% endif %}
and having it work if I didn't put var1 into the context. Jinja2 gives me an undefined error. Is there an easy way to say {% if var1 == None %} or similar?
From the Jinja2 template designer documentation:
{% if variable is defined %}
value of variable: {{ variable }}
{% else %}
variable is not defined
{% endif %}
{% if variable is defined %} is true if the variable is None.
Since not is None is not allowed, that means that
{% if variable != None %}
is really your only option.
You could also define a variable in a jinja2 template like this:
{% if step is not defined %}
{% set step = 1 %}
{% endif %}
And then You can use it like this:
{% if step == 1 %}
<div class="col-xs-3 bs-wizard-step active">
{% elif step > 1 %}
<div class="col-xs-3 bs-wizard-step complete">
{% else %}
<div class="col-xs-3 bs-wizard-step disabled">
{% endif %}
Otherwise (if You wouldn't use {% set step = 1 %}) the upper code would throw:
UndefinedError: 'step' is undefined
In the Environment setup, we had undefined = StrictUndefined, which prevented undefined values from being set to anything. This fixed it:
from jinja2 import Undefined
JINJA2_ENVIRONMENT_OPTIONS = { 'undefined' : Undefined }
Consider using default filter if it is what you need. For example:
{% set host = jabber.host | default(default.host) -%}
or use more fallback values with "hardcoded" one at the end like:
{% set connectTimeout = config.stackowerflow.connect.timeout | default(config.stackowerflow.timeout) | default(config.timeout) | default(42) -%}
You can use kind of Jinja Elvis operator
{{ 'OK' if variable is defined else 'N/A' }}
or additionally check emptiness
{{ 'OK' if (variable is defined and variable) else 'N/A' }}
Jinja templates - Template Designer Documentation
{% if variable is defined %} works to check if something is undefined.
You can get away with using {% if not var1 %} if you default your variables to False eg
class MainHandler(BaseHandler):
def get(self):
var1 = self.request.get('var1', False)
I had an issue like this in Ansible. Ended up having to do a test on both #Garret and #Carsten / #azalea answers, so:
{% if variable is defined and variable %}
value of variable: {{ variable }}
{% else %}
variable is not defined or is falsy
{% endif %}
You can do this :
- debug:
msg: "Executed only if variable is defined"
when:
- variable is defined