Read URL variables from Flask context processor

问题:

Suppose I have a simple route with a variable part:

@app.route('/post/<int:post_id>')
def show_post(post_id):
    return 'Post %d' % post_id

Now I want to register a context processor that

1. Only runs when the view function is called with post_id as a parameter
2. somehow has access to post_id, without having to re-parse the URL all over again with e.g. re.match

essentially:

@app.context_processor
def foo():
    post_id = ???
    return {'bar': some_function(post_id)}

If I could access the **kwargs passed to show_post in this example from the context processor I could do it, but I've found no way to do that. Any ideas?

回答1:

Use request.view_args:

@app.context_processor
def provide_foo():
    if "post_id" in request.view_args:
        post_id = request.view_args["post_id"]
        return {"bar": some_function(post_id)}