Example #1
Reference: Jinja
Syntax:
default(value, default_value=u'', boolean=False)
Example #1
If the value is undefined it will return the passed default value, otherwise the value of the variable:
{{ my_variable|default('my_variable is not defined') }}
This will output the value of my_variable if the variable was defined, otherwise ‘my_variable is not defined’. If you want to use default with variables that evaluate to false you have to set the second parameter to true:
{{ ''|default('the string was empty', true) }}
Example #2
Reference: webforefront
The default or d filter is used to specify a default value if a variable is undefined or is false (i.e. it doesn’t exist or is empty). For example, the filter statement:
{{variable|default("no value")}}
outputs “no value” only if the variable is undefined, otherwise it outputs the variable value.
Example #3
If in addition you want to provide a default value for a variable that evaluates to false , is None or is an empty string, you have to add True as a second filter parameter, e.g:
{{variable|default("no value",true)}}
outputs “no value” if the variable is undefined, false , is None or is an empty string).
As always, if you have any questions or have a topic that you would like me to discuss, please feel free to post a comment at the bottom of this blog entry, e-mail at will@oznetnerd.com, or drop me a message on Reddit (OzNetNerd).
Note: The opinions expressed in this blog are my own and not those of my employer.
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