I have this template (set_ip.j2):
{% if '{{ansible_env.SSH_CONNECTION.split(' ')[2]}}' == '{{ ip_ssh }}' %}
address = {{ ip_db }}
name='db1'
{% endif %}
but this condition not work! I want address and name set by this value in the config file.
Never ever use nested expressions in Jinja2:
{% if ansible_env.SSH_CONNECTION.split(' ')[2] == ip_ssh %}
address = {{ ip_db }}
name='db1'
{% endif %}
I'm trying to negate IN.
Basically, I want to output true, when keyword1 is in keywords, but keyword11 isn't.
Please note: keyword11 ("my_keyword_11") starts with keyword1 ("my_keyword_1"). keywords has to stay a string, can't split/explode by the comma.
{% set keywords = 'my_keyword_1, my_keyword_2' %}
{% set keyword1 = 'my_keyword_1' %}
{% set keyword11 = 'my_keyword_11' %}
{% if ((keyword1 in keywords) and (keyword11 not in keywords)) %}
true
{% endif %}
Any ideas? Thanks in advance!
Your code is ok as you can view in this twigfiddle
I want to use an if statement in Liquid with multiple conditionals. Something like:
{% if (include.featured == "true" and product.featured == "true") or (include.featured == "false" and product.featured == "false") %}
Multiple conditionals don't seem to work. Have I got the syntax wrong or can Liquid not handle this sort of if statement?
Unfortunately, Liquid has a poor implementation of boolean algebra.
Using Liquid's operators and tags, here is a dirty way to achieve it:
{% if include.featured == true and product.featured == true %}
{% assign test = true %}
{% endif %}
{% if include.featured == false and product.featured == false %}
{% assign test = true %}
{% endif %}
{% if test %}
Yepeeee!
{% endif %}
Another way you can condense this is to combine else if statements, and booleans don't necessarily need the "==" when evaluating true:
{% if include.featured and product.featured %}
{% assign test = true %}
{% elsif include.featured == false and product.featured == false %}
{% assign test = false %}
{% endif %}
How do I check if a variable is False using Django template syntax?
{% if myvar == False %}
Doesn't seem to work.
Note that I very specifically want to check if it has the Python value False. This variable could be an empty array too, which is not what I want to check for.
For posterity, I have a few NullBooleanFields and here's what I do:
To check if it's True:
{% if variable %}True{% endif %}
To check if it's False (note this works because there's only 3 values -- True/False/None):
{% if variable != None %}False{% endif %}
To check if it's None:
{% if variable == None %}None{% endif %}
I'm not sure why, but I can't do variable == False, but I can do variable == None.
Django 1.10 (release notes) added the is and is not comparison operators to the if tag. This change makes identity testing in a template pretty straightforward.
In[2]: from django.template import Context, Template
In[3]: context = Context({"somevar": False, "zero": 0})
In[4]: compare_false = Template("{% if somevar is False %}is false{% endif %}")
In[5]: compare_false.render(context)
Out[5]: u'is false'
In[6]: compare_zero = Template("{% if zero is not False %}not false{% endif %}")
In[7]: compare_zero.render(context)
Out[7]: u'not false'
If You are using an older Django then as of version 1.5 (release notes) the template engine interprets True, False and None as the corresponding Python objects.
In[2]: from django.template import Context, Template
In[3]: context = Context({"is_true": True, "is_false": False,
"is_none": None, "zero": 0})
In[4]: compare_true = Template("{% if is_true == True %}true{% endif %}")
In[5]: compare_true.render(context)
Out[5]: u'true'
In[6]: compare_false = Template("{% if is_false == False %}false{% endif %}")
In[7]: compare_false.render(context)
Out[7]: u'false'
In[8]: compare_none = Template("{% if is_none == None %}none{% endif %}")
In[9]: compare_none.render(context)
Out[9]: u'none'
Although it does not work the way one might expect.
In[10]: compare_zero = Template("{% if zero == False %}0 == False{% endif %}")
In[11]: compare_zero.render(context)
Out[11]: u'0 == False'
I think this will work for you:
{% if not myvar %}
You could write a custom template filter to do this in a half-dozen lines of code:
from django.template import Library
register = Library()
#register.filter
def is_false(arg):
return arg is False
Then in your template:
{% if myvar|is_false %}...{% endif %}
Of course, you could make that template tag much more generic... but this suits your needs specifically ;-)
In old version you can only use the ifequal or ifnotequal
{% ifequal YourVariable ExpectValue %}
# Do something here.
{% endifequal %}
Example:
{% ifequal userid 1 %}
Hello No.1
{% endifequal %}
{% ifnotequal username 'django' %}
You are not django!
{% else %}
Hi django!
{% endifnotequal %}
As in the if tag, an {% else %} clause is optional.
The arguments can be hard-coded strings, so the following is valid:
{% ifequal user.username "adrian" %}
...
{% endifequal %}
An alternative to the ifequal tag is to use the if tag and the == operator.
ifnotequal
Just like ifequal, except it tests that the two arguments are not equal.
An alternative to the ifnotequal tag is to use the if tag and the != operator.
However, now we can use if/else easily
{% if somevar >= 1 %}
{% endif %}
{% if "bc" in "abcdef" %}
This appears since "bc" is a substring of "abcdef"
{% endif %}
Complex expressions
All of the above can be combined to form complex expressions. For such expressions, it can be important to know how the operators are grouped when the expression is evaluated - that is, the precedence rules. The precedence of the operators, from lowest to highest, is as follows:
or
and
not
in
==, !=, <, >, <=, >=
More detail
https://docs.djangoproject.com/en/dev/ref/templates/builtins/
Just ran into this again (certain I had before and came up with a less-than-satisfying solution).
For a tri-state boolean semantic (for example, using models.NullBooleanField), this works well:
{% if test.passed|lower == 'false' %} ... {% endif %}
Or if you prefer getting excited over the whole thing...
{% if test.passed|upper == 'FALSE' %} ... {% endif %}
Either way, this handles the special condition where you don't care about the None (evaluating to False in the if block) or True case.
I have had this issue before, which I solved by nested if statements first checking for none type separately.
{% if object.some_bool == None %}Empty
{% else %}{% if not object.some_bool %}False{% else %}True{% endif %}{% endif %}
If you only want to test if its false, then just
{% if some_bool == None %}{% else %}{% if not some_bool %}False{% endif %}{% endif %}
EDIT: This seems to work.
{% if 0 == a|length %}Zero-length array{% else %}{% if a == None %}None type{% else %}{% if not a %}False type{% else %}True-type {% endif %}{% endif %}{% endif %}
Now zero-length arrays are recognized as such; None types as None types; falses as False; Trues as trues; strings/arrays above length 0 as true.
You could also include in the Context a variable false_list = [False,] and then do
{% if some_bool in false_list %}False {% endif %}
Look at the yesno helper
Eg:
{{ myValue|yesno:"itwasTrue,itWasFalse,itWasNone" }}
I've just come up with the following which is looking good in Django 1.8
Try this instead of value is not False:
if value|stringformat:'r' != 'False'
Try this instead of value is True:
if value|stringformat:'r' == 'True'
unless you've been really messing with repr methods to make value look like a boolean I reckon this should give you a firm enough assurance that value is True or False.
This is far easier to check in Python (i.e. your view code) than in the template, because the Python code is simply:
myvar is False
Illustrating:
>>> False is False
True
>>> None is False
False
>>> [] is False
False
The problem at the template level is that the template if doesn't parse is (though it does parse in). Also, if you don't mind it, you could try to patch support for is into the template engine; base it on the code for ==.
you can use the int value of true and false
True = any int
False = zero
so, if we take an example:
{% if user.is_authenticated == 1 %}
do something
{% endif %}
this mean in python
if user.is_authenticated:
#do something
and
{% if user.is_authenticated == 0 %}
do something
{% endif %}
this mean in python
if not user.is_authenticated :
#do something
OR equal
if !(user.is_authenticated) :
#do something
OR equal
if user.is_authenticated == False :
#do something
It can be done:if you use "select" tag.
{% if service.active == 0 %} selected {% endif%}
I have some django code that prints a BooleanField
it is rendered as True or False, can I change the label to be Agree/Disagree or do I need to write logic for that in the template?
{{ bool_var|yesno:"Agree,Disagree" }}
You can also provide an additional string for the None case. See the docs for yesno for details.
Just another way if you want to have more options like adding HTML elements and classes
{% if var == True %} Yes {% else %} No {% endif %}
You can change Yes and No to any html element; an image or span element
Any of the following may be tried with consistent results:
A.
{% if form.my_bool.value %}
{{ "Yes" }}
{% else %}
{{ "No" }}
{% endif %}
B.
{{ form.my_bool.value|yesno }}
C.
{{ form.my_bool.value|yesno:"Yes,No" }}
D.
{% if form.my_bool.value == True %} Yes {% else %} No {% endif %}
Or simply,
{{ form.my_bool.value }} # Here the output will be True or False, as the case may be.
If your models have been defined as
class mymodel(models.Model):
choices=((True, 'Agree'), (False,'Disagree'),(None,"Maybe"))
attr = models.BooleanField(choices=choices, blank=False, null=True)
You can use the built-in method to retrieve the "pretty" string associated with the value by in your template with
{{ object.get_attr_display }}