如何放置一种格式，在该格式中分析用户上传的文件，然后将其显示在新的url上？

Question

Ultimately, I want it so that when users upload a file, it parses the file and then creates a new url (using save_url ) where it displays the output of that parsing.

Here is the edit.pt that renders the form:

<form action="/add_page" method="post" accept-charset="utf-8" enctype="multipart/form-data">
<label for="stl">Stl</label>
<input name="stl" type="file" value="" />
<input type="submit" value="submit"/>
</form>

Here is the add_page section of views.py :

@view_config(route_name='add_page', renderer='templates/edit.pt')
def add_page(request):
    input_file=request.POST['stl'].file
    i1, i2 = itertools.tee(input_file)
    vertices = [map(float, line.split()[1:4])
                for line in i1
                if line.lstrip().startswith('vertex')]

    normals = [map(float, line.split()[2:5])
                for line in i2
                if line.lstrip().startswith('facet')]

    ordering=[]
    N=len(normals)

    ...(parsing data)...


    return data
    if data is None:
        displayNotification['please upload file']
    if 'stl' in request.params:
        name=request.params('name')
        page=Page(name,data)
        return HTTPFound(location=request.route_url('view_page',pagename=name))
    save_url=request.route_url('add_page',pagename=name)
    page=Page('','')
    return dict(page=page,save_url=save_url)

And when I try and go to http://localhost:6543/add_page/new (to add a new page with a new url), I get this error:

KeyError: "No key 'stl': Not a form request".

This error occurs on the line under def add_page(request): . I am formatting it like so as to go off of this tutorial .

Answer 1

There are basically two scenarios of "what to do after you saved data on form submit":

1. you save the data (say, the result of the file parsing) to some permanent storage (database, which will give you some unique URI to address that file (say, /files/123123 ). Then you just issue an HTTP redirect to that location:

    @view_config(renderer="templates/form_view.pt") def form_view(self): if self.request.method == 'POST': if _validation_passed(request): new_url = _save_data(request) return HTTPFound(new_url) else: return _render_form(values=request.POST, msg="Validation failed") # We are a GET not a POST, render empty form return _render_form() 

The new "page" stays permanently, so if you just visit /files/123123 in your browser you'll see the same page.

1. Alternatively, your view receives an HTTP post, does something with the data and, instead of redirecting to another view, just returns a blob of HTML just like any other "normal" view. This is used when, say, the form fails validation and you want to re-display the form, but is also useful when you do not save the data anywhere, so basically you don't have an URI to redirect to.

    @view_config(renderer="templates/form_view.pt") def form_view(self): if self.request.method == 'POST': if _validation_passed(request): return _render_data(request) else: return _render_form(values=request.POST, msg="Validation failed") # We are a GET not a POST, render empty form return _render_form() 

In this case, the result page will only be visible after the file is submitted, to view it again the user will need to re-upload the file.

Just follow one of those patterns and you'll be able to sort the things out.

There is an additional complication with file submits - you generally can't re-display the form with the file field populated without doing some trickery with storing a file in a temporary location on the server.