How do I call render_template() once per minute flask - python-2.7

Question

I am new to Flask. How do I call render_template('prices.html', stock_price) once every minute for a given page that is fed by constantly changing data?
I tried this:
throttle.Throttle(period=60) # 60 second throttle
while True:
stock_price = get_stock_price()
render_template('prices.html', stock_price=stock_price)
throttle.check() # Check if 60 seconds have passed otherwise sleep
The only thing that does work is return render_template(...). Apparently render_template() must be part of a return-statement. Unfortunately, once return is called the game is over.
How do I accomplish this? I'm assuming it is just ignorance on my part.

Answer 1

When you render the template you run the Flask process and return an HTML after the template file rendered, and as your said, you use return and the game is over.
Even if you will find a really hard-code way to do it, it's not a good way to do it. You will waste too much server calls and a user waiting time.
The easy way to do it
Writing a really simple Python function that return only the stock number(i guess you already have one - get_stock_price() )
But i would decorate it with a route(Lets say "/getprice"). Every one who will get to this page will get a black page but the stock price text.
Now for the real magic - use JQuery-AJAX on the HTML page to call this function:
$.ajax({
type: "POST",
url: "/getprice",
})
.done(function( price ) {
$("#price-box").val(price)
});
Hey but wait, what about my "once per minute"??
of curse we can insert this ajax call into setInerval() function like this:
setInterval(function() {
$.ajax({
type: "POST",
url: "/getprice",
})
.done(function( price ) {
$("#price-box").val(price)
});
}, 1000 * 60);
Tell me if you need any help with that.
The Pro way to do it
Ok, so you managed to send a request for your get_stock_price() function once per minute.
Great.
But what about performance?
I guess your get_stock_price() doing some other request or even some web scraping which, again, could be really hard for the server (think what going on when 10,000 users using this page).
What i would do is:
Store the data from get_stock_price() in your DB every minute(Cron Job would do the job), then when a user asks(AJAX request) for this data, pull it out of the DB.
This way the server will work on the background and the user won't see any different with his data loading speed.