pythontemplate-enginejinja2

jinja2 print to console or logging


I'm kind of new to Jinja2 and am wondering if there is a way to make the templates, while being generated, to print to the console or redirect some output to some kind of stream?

Since Jinja2 templates may have logic inside, I think it would be useful sometimes to log some info in to some kind of logfile, or at least get printed to console.

Is this possible or am I just talking garbage?


Solution

  • I think you can achieve it using filters (http://jinja.pocoo.org/docs/api/#custom-filters) or extensions (http://jinja.pocoo.org/docs/extensions/#adding-extensions). The idea is to just print the filter or extension straight to console.

    Not tested but the filter should be something like:

    def debug(text):
      print text
      return ''
    
    environment.filters['debug']=debug
    

    To be used as:

    ...<p>Hello world!</p> {{"debug text!"|debug}}...
    

    Remember to remove the debug on production code!