I have a table in the navigation system of my webapp that will be populated with up-to-date information each time a page is rendered. How could I avoid putting the following code in each view?
def myview(): mydict = code_to_generate_dict() return render_template('main_page.html',mydict=mydict) mydict is used to populate the table. The table will show up on each page
You can use Flask's Context Processors to inject globals into your jinja templates
Here is an example:
@app.context_processor def inject_dict_for_all_templates(): return dict(mydict=code_to_generate_dict()) To inject new variables automatically into the context of a template, context processors exist in Flask. Context processors run before the template is rendered and have the ability to inject new values into the template context. A context processor is a function that returns a dictionary. The keys and values of this dictionary are then merged with the template context, for all templates in the app:
dict to be returned, whether my variable to be injected is a string, list, or any other datatype (including a dict)
context_processor is on the Flask application object so it works for any view processed by that application. If you have multiple applications, then you would need to repeat it.app = Flask(...)). If those views are all serviced by the previous app, then they share context.
Instead of a decorator, you can pass a function where the necessary context processor will be
app = Flask(__name__) app.context_processor(templatetags) def templatetags(): def format_price(amount, currency="€"): return f"{amount:.2f}{currency}" return dict( format_price=format_price, ) 'index.html'
{{ format_price(0.33) }} Write your own render method do keep yourself from repeating that code. Then call it whenever you need to render a template.
def render_with_dict(template): mydict = code_to_generate_dict() return render_template(template, mydict=mydict) def myview(): return render_with_dict('main_page.html') 