CODEWITHSUNDEEP
pythongoogle-app-engineurl
PlexLuthor
PlexLuthor

Reputation: 578

Remove URL Params after page loads in Google App Engine

First of all, I am very new to web programming in general. I've read lots of tutorials online and it's a little confusing since some of them are out-dated. So if I'm heading down a path that is fundamentally wrong, I'd love suggestions about The Right Way. Having said that, this is just a for-fun project, so if there is a simple (<10 lines) way to get what I want, I'd love to see quick results today even if long-term I end up fundamentally changing things.

So anyway, I'm using Google App Engine (Python 2.7) to do a simple calculation. I show a form, the user fills in values, clicks a button at the bottom, and some result text is displayed with the result of the calculation. This part is working fine.

For my own testing, it's annoying to always re-type the input values, and some of the fields aren't totally obvious to users, so I'd like to be able to send a link to someone off the form "http://buggyapp.appspot.com/calculation?input1=100&input2=200" and have it fill in those two parameters. This part works, too.

The problem is when the user loads that sort of link, changes one of the values in the form, and then clicks the button. Instead of using the (changed) form value, it uses the value in the URL. I'd like to fix that, and ideally I'd like the URL bar to not even show the URL Params after the page loads.

I'm not sure what info is necessary to help you find what I'm doing wrong.

Here's a section from the HTML, which is a Jinja2 template:

<form method="post">
  <input value="{{ input1 }}" name="input1">
  <input value="{{ input2 }}" name="input2">
  <button class="submit" type="submit">Calculate</button>
</form>
<p>{{ result }}</p>

Here's the python code:

def get(self):
  input1 = request.get('input1')
  input2 = request.get('input2')

  # some irrelevant(?) code to set default values on the initial load if there are no URL Params

  result = str(input1+input2) #actual calculation slightly more complicated than this
  template = JINJA_ENVIRONMENT.get_template('calculation.html')
  self.response.write(template.render(vars()))

It seems to behave the same no matter whether I put the calculation in the get handler or post handler. At the moment, I'm simply calling one from the other:

def post(self):
  input1 = request.get('input1')
  print input1 # even this shows the URL value (if one exists), not form value
  return self.get();

So, my next step to make it work would be to change the names of the form inputs so they are different from the URL Params, and add extra code to merge the potential input sources. But that won't really get me what I want, which is for the URL Params to disappear once they have populated the input forms. It also complicates the part of the code that generates those sorts of links.

I'd prefer a Python-only solution, but I'm open to using javascript. There are other stack overflow questions/answers that imply a javascript mechanism will do what I want, but I don't understand any of them well enough to apply them to my problem.

I'm sure I'm doing lots of other things wrong, and I may have over-simplified things or not posted enough info. I'm here to learn, so fire away. And thanks in advance for the help.

tl;dr- How do I use the URL Params once and then remove them from the URL so they don't override form inputs on subsequent posts?

Upvotes: 1

Views: 187

Answers (1)

dragonx
dragonx

Reputation: 15143

HTTP GET requests usually include the parameters in the URL since there's no other place to pass them (there's no request body).

HTTP POST requests usually include the parameters in the request body, though it's still possible to include the parameters in the URL.

It looks like you're using some sort of Javascript to post the form. Make sure you are using a POST request and putting the parameters in the POST body. Most libraries automatically put params in the POST body as long as you're issuing a POST request.

EDIT:

Forms usually issue POST requests by default. Usually the <form> element will have an action attribute that specifies the URL to send to. However, if it doesn't have an action attribute it'll issue a POST request to the current URL.

In your case the current URL contains parameters and those are submitted again with your request. You should have a few options.

  1. Specify the action in your form so you aren't submitting to the same url with parameters already attached.

  2. In your request handler, read the data out of the post body (request.POST['input1']) instead of the url.

Upvotes: 1

Related Questions