Pass SQLAlchemy Query to Base Jinja Template

Question

I am creating an application using Flask, SQLAlchemy, and Jinja. Almost every page in my application uses a base.html file (which is essentially a shell with a navbar and sidebar), and then builds upon that. I display information in the base.html file that is the result of a SQLAlchemy query:

user.company.users.filter(User.account_approved == False).all()

and right now I am passing it to a single view by using:

@splash.route('/dashboard')
@login_required
def dashboard():
    return render_template('templates/dashboard.html', pendingUsers=g.user.company.users.filter(User.account_approved == False).all())

However, this only allows the base.html view to have this information when I load the /dashboard route, and if I load any other route that uses the same base.html file, running {{ pendingUsers}} outputs not text. How can I go about rendering that query in every route that uses base.html? I tried making the query directly in the jinja template, but I could not figure out how to do that (for example, running {{ g.user.company.users }} simply outputted the SQL query for that SQLAlchemy statement.

Answer 1

What you are doing is not going to work because your query is not evaluated when you call it within render_template. Instead, the sql query string is sent as is to the template.

You can use a custom decorator since only want to do this for some views/pages.

def get_pending_users(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        pending_users = user.company.users.filter(User.account_approved == False).all()
        if g.pending_users is None:
           g.pending_users = pending_users
        return f(*args, **kwargs)
    return decorated_function

In your view, you can call it as:

@app.route('/',methods = ['GET','POST])
@get_pending_users
def whatever():
    return render_template('templates/dashboard.html')

Then, in your template, just call g.pending_users

 {{ g.pending_users }}