how to forbidden page cache on rails -

-

i'm design shopping cart,there 2 web page,

first checkout page,and second order_success page

if user use go button on webbrowser go checkout page after user have go order_success page.

so want find way forbidden let use go back,

is there way on rails archieve this?

"i know user use go button,if there cache in client, user still see & re-submit, not expect" [was meaning?]

if want prevent user resubmit same request, may add hidden field (just random) , store in session after request has been processed:

if params[:token] == session[:used_token]   render_already_processed_notice   return end if @cart.save   session[:used_token] = params[:token] ....

if use cart id in request, may use status of cart model:

@cart = cart.find(params[:id]) render_some_notice , return if @cart.done? .... @cart.done = true @cart.save

personally not create checkout , order_success pages. create single page - cart status, , depending on model status display different content.

if action may executed once (like closing cart or finalizing transaction) there no problem: render_something , return if @cart.already_closed?

on pages, multiple submits possible, not welcome (like adding product cart - user can add 2 identical products) may 2 things:

1) use mentioned token, detect when user pressed f5, , ask him whether action should done twice, or

2) accept requests, provide user methods 'rollback' actions (allow him delete products cart), , ensure cart content verified before final acceptance.


Comments

Post a Comment

Popular posts from this blog

android - Spacing between the stars of a rating bar? -

-
ho can set spacing beween stars? thats ratingbar: ratingbar = (ratingbar) inflater.inflate(r.layout.ratingbar, null); ratingbar.setlayoutparams(new layoutparams(layoutparams.wrap_content, layoutparams.wrap_content)); the layout: <?xml version="1.0" encoding="utf-8"?> <ratingbar xmlns:android="http://schemas.android.com/apk/res/android" style="@style/mystyle" android:layout_alignparentright="true" android:layout_height="19dp" android:layout_width="wrap_content" android:numstars="5"> </ratingbar> the style: <style name="mystyle" parent="@android:style/widget.ratingbar"> <item name="android:progressdrawable">@drawable/android_r2_ratingstar_yellow</item> <item name="android:indeterminatedrawable">@drawable/android_r2_ratingstar_grey</item> </style> thanks, cheers you have ...
Read more

html - Instapaper-like algorithm -

-
does of algorithm extracts contents webpage? instapaper ? there 2 steps instapaper does: find main content block on page (excluding headers, footers, menus etc) from content block extract , format text to find content block (typically html block element, div containing key page text content) instapaper uses algorithm 1 used readability . can @ source of readability.js see what's going on, @ core tries find area on page highest text/link ratio, although has other simple scoring metrics (e.g. off top of head, things ratio of text commas, para elements etc) go heuristics. once have identified root node element, relevant content, you'll need format it, if want can pull node element containing text out of source document , insert yours, in reality you'll want remove existing styles , apply own, standard , feel. if want output nice text-only can use jericho's renderer . update1 : should mention else instapaper - follow 'pagination' links (...
Read more

c# - How to execute a particular part of code asynchronously in a class -

-
i creating speech recognition engine that's going respond user commands.i have created button enable , disable speech recognition per user convenience.i have used dispose() of speech engine disable speech recoginition.here code private void button1_click(object sender, routedeventargs e) { engineon = !engineon; if (engineon) { speechengine = speech.createspeechengine(); //speech class creates , returns new speech engine. speechengine.audiolevelupdated += new eventhandler<audiolevelupdatedeventargs>(speechengine_audiolevelupdated); // use system's default microphone speechengine.setinputtodefaultaudiodevice(); speechengine.loadgrammar(new dictationgrammar()); // start listening speechengine.recognizeasync(recognizemode.multiple); } else { speechclass.myengine.dispose(); } } but disposal of speech obj...
Read more