[Rails-spinoffs] Re: About X-JSON header and evil things... ;)

[Colin Mollenhour]

This change, while I think is a good idea in general, will be somewhat difficult to make use of if the new JSON object replaces the old JSON object. I, and apparently others, use X-JSON often for error checking, debug messages, status flags, etc..  When your application requires the occasional use of raw HTML and you don't want to encode it all in a JSON message, it is very useful. However, I still use JSON encoded data in the response body because of the size limitations of the X-JSON header. Having X-JSON *replaced* by the evaluated responseText, will make it difficult for when I want to still use the X-JSON header for error/debug/status info, but send the main response body as either plain X-HTML or JSON due to the size limit. To make it more clear, I would have to account for the following possible scenarios on the server side in order to make use of the new feature: 1) If response is HTML then error/debug is X-JSON 2) If response is JSON then error/debug is in response JSON It would be nice if the body JSON didn't replace the X-JSON because then I could always use X-JSON for error/debug regardless of what is in the responseText. This just seems like better separation of data and error/status handling to me. My suggestion is perhaps rather than replacing X-JSON it should be placed inside the response object? e.g.  "xhr.json" similar to "xhr.responseText" Thoughts? Colin ----code examples----- Hypothetical JS using my suggestion: onComplete: function(xhr,json){     console.debug(xhr.responseText); //the responseText     console.debug(xhr.json); //the evaluated responseText (if "Content-type: application/x-json")     console.debug(json); //the X-JSON evaluated header     if(json && json.error){ alert(json.error); return; }     if(json && json.login){ showLogin(); return; }     //do something with xhr.json } Hypothetically on the server-side (PHP): ob_start(); $status = Array(); $json = Array(); if(!$loggedIn){     $status['login'] = 'true';     header('X-JSON: ('.json_encode($status).')');     return; } if( /*handling request using JSON */ ){     if(/*error*/){ $status['error'] = 'Error message!'; }     else{ $json['data'] = Array(/* data here */); } }else if( /*handling request with HTML */){     if(/*error*/){ $status['error'] = 'Error message!'; }     else{ print '<b>HTML! Yay!</b>'; } } $content = ob_get_clean(); if($status){     header('X-JSON: ('.json_encode($status).')'); } if($json){     header('Content-type: application/x-json');     print '('.json_encode($json).')'; }else{     print $content; } Alexander Presber wrote: Am 22.01.2007 um 13:46 schrieb Dave Crane: On Saturday 20 January 2007 15:22, Kjell Bublitz wrote: Secondly, there is no point for X-JSON to be a status message carrier or "just for simple stuff". Drop it entirely. It's is unnecessary. Most people will have an own error format / object notation which they transport in the responseText as a replacement for the expected content and act on it. (eg include a "status" key) My reading of the X-JSON header was that it's useful in cases where you want to pass some secondary data back with a response. The practice of 'piggy-backing' data in this way isn't to everybody's taste, but it can be a useful way of avoiding extra traffic. Rails & Prototype both have a strong bent towards delivering fragments of HTML rather than data in the response. In this case, If you're sending back content, I don't see how to easily embed secondary data inside the main response body, other than stuffing it into a hidden DIV, which loses several hundred points for elegance. Sure, if you're delivering data anyway, X-JSON isn't particularly useful. Just want to support that opinion. We are using the X-JSON header exactly for that. Alex On Monday 22 January 2007 12:42, Mislav wrote: Will be done: http://dev.rubyonrails.org/ticket/7295 Just saw this come in on the list - sounds like a good suggestion to me. Just my $0.02 Dave -- ---------------------- Author Ajax in Action http://manning.com/crane Ajax in Practice http://manning.com/crane2 Prototype & Scriptaculous Quickly http://manning.com/crane3 --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Spinoffs" group. To post to this group, send email to rubyonrails-spinoffs@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/rubyonrails-spinoffs?hl=en -~----------~----~----~----~------~----~------~--~---