render jinja2 template without a Flask context

Question

I have a Flask application that calls flask.render_template without problems when it is invoked from a flask http request.

I need the same method to work outside of flask (from a python back end program)

resolved_template =  render_template(template_relative_path, **kwargs)

I could use the jinja2 api, but I would like the same method to work, in both contexts (flask and command line)

score 29 · Answer 1 · answered Nov 26 '15 at 17:49

29

If you want to completely bypass flask and use purely Jinja for rendering your template, you can do as such

import jinja2

def render_jinja_html(template_loc,file_name,**context):

    return jinja2.Environment(
        loader=jinja2.FileSystemLoader(template_loc+'/')
    ).get_template(file_name).render(context)

And then you can call this function to render your html

answered Nov 26 '15 at 17:49

Shankar ARUL

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Better yet, just use Flask's own default jinja environment with `app.jinja_env`. – 0x24a537r9 Aug 31 '16 at 05:47
What do you pass in to that function? Especially with ```template_loc```? – Nyi Nyi Hmue Aung Apr 20 '22 at 11:21
for some reason passing `template_loc+'/'` doesn't work for me, instead pass template_loc and make sure you add the `/` at the end – omercotkd Jun 02 '22 at 08:14

score 13 · Accepted Answer · answered May 21 '15 at 19:13

13

You need to render it in an app context. Import your app in your backend code and do the following.

with app.app_context():
    data = render_template(path, **context)

answered May 21 '15 at 19:13

davidism

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score 1 · Answer 3 · answered Nov 26 '15 at 17:56

1

What I use is this code:

import jinja2
template_values = {
  'value_name_in_html': value_name_in_python,   
}

template = JINJA_ENVIRONMENT.get_template("file_patch")
self.response.write(template.render(template_values))

answered Nov 26 '15 at 17:56

Y2H

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It's complaining JINJA_ENVIRONMENT is not set. How should I set it ? – blissweb Aug 12 '20 at 02:58
Hi @blissweb, I am sorry I have not used Jinja in like 4 years so this info is not at the top of my head at the moment. If I get a chance later today I’ll look at it and get back to you. – Y2H Aug 12 '20 at 08:13

devtonic · Answer 4 · 2023-02-13T10:25:44.133

You could use this simple steps to create and render a Jinja HTML template without using Flask. I use it to create email newsletter templates for my WordPress blog:

from jinja2 import Template

# Create a template string
template_string = """
<html>
<head>
    <title>{{ title }}</title>
</head>
<body>
    <h1>Hello, {{ name }}!</h1>
</body>
</html>
"""

# Create a template object from the string
template = Template(template_string)

# Render the template with context data
rendered_template = template.render(title="My Example Page", name="John Doe")

# Print the rendered template
print(rendered_template)

render jinja2 template without a Flask context

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