Not sure what to do.....can I run this by you guys?

Ben Rubinstein benr_mc at cogapp.com
Sun Mar 18 15:39:19 CET 2018


I think this depends on the base URL.  If it's with a simple URL, there's no 
reason why an appended '#' parameter should cause a browser to request it 
fresh; as Mike says, it indicates scrolling to an anchor in the page. So it's 
perfectly reasonable for a smart browser - or a caching layer on the server, 
or in a proxy somewhere between you and the server - to use a cached version 
of that page ignoring the '#' suffix.

With a simple URL, the better choice is to use "?" to append a parameter (I 
usually use 'the milliseconds' to guarantee that it's unique). Neither the 
browser nor any caching layer on the chain between the user agent and the 
source system should recognise it as the same URL, so this should force a 
fresh load. You can just use e.g.
	put "?" & the milliseconds after tURL

or to be more explicit, name the parameter something e.g.
	put "?nocache=" & the milliseconds after tURL
or

	put "?uniqueid=" & the milliseconds after tURL

The only downside of using "?" is that if the URL may already includes 
parameters starting with "?" (which is what I mean by "not a simple URL"), you 
need to test for that and use "&" instead of "?" to indicate that this is an 
additional parameter; and if this is a dynamic request, which uses the 'query 
parameters' in the URL to decide what to return, you need to be sure that 
adding your parameter won't affect it!

On 16/03/2018 13:31, Mike Bonner via use-livecode wrote:
> Another way around the cache problem is to use the #2 trick at the end of
> the url.  Send each request with a pound and different number at the end of
> the url and it'll be seen as a new request thus doing an end run around the
> cache.  Since it designates an inline anchor position on the page, it
> should have zero affect on the way the url functions.  (unless things have
> changed, the associated anchor doesn't need to exist on the page)
> 
> Thanks for the neat trick Charles. :)
> 
> On Fri, Mar 16, 2018 at 7:24 AM, Tom Glod via use-livecode <
> use-livecode at lists.runrev.com> wrote:
> 
>> Wow....I'm impressed....thats quite a hack Charles..I will study all this
>> see how far I get.....
>>
>> Thank you gentlemen....you are Rockstars!!
>>
>> On Fri, Mar 16, 2018 at 7:13 AM, Lagi Pittas via use-livecode <
>> use-livecode at lists.runrev.com> wrote:
>>
>>> Maybe not 100% reliable but ....
>>>
>>> https://stackoverflow.com/questions/1341089/using-meta-
>>> tags-to-turn-off-caching-in-all-browsers
>>>
>>> Regards Lagi
>>>
>>> On 16 March 2018 at 09:48, Charles Warwick via use-livecode
>>> <use-livecode at lists.runrev.com> wrote:
>>>>   Hi Tom,
>>>>
>>>> If the site you are trying to contact has CORS enabled appropriately,
>>> then you can do something like this...
>>>>
>>>> With the LiveCode browser widget, you can call JavaScript functions
>> from
>>> LC script and have the JavaScript functions call LC handlers in return.
>>> JavaScript has the capability to perform asynchronous HTTP requests.
>>>>
>>>> You can create a HTML page that you automatically load up in the
>> browser
>>> widget that has a small JavaScript function which you can call from LC
>> with
>>> ‘do in widget’.   All this function needs to do is issue an asynchronous
>>> HTTP call to the URL passed to it as a parameter and when it receives the
>>> data, return it back to your LC script by calling a nominated LC handler
>>> and passing the returned data as a parameter.
>>>>
>>>> The HTML page would look something like this:
>>>>
>>>> <html>
>>>> <head>
>>>> <title>Javascript Async Test</title>
>>>> <script type="text/javascript">
>>>>
>>>> function httpGetAsync(theUrl)
>>>> {
>>>>      var xmlHttp = new XMLHttpRequest();
>>>>      xmlHttp.onreadystatechange = function() {
>>>>          if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
>>>>              liveCode.httpRequestComplete(theUrl,
>> xmlHttp.responseText);
>>>>      }
>>>>      xmlHttp.open("GET", theUrl, true); // true for asynchronous
>>>>      xmlHttp.send(null);
>>>> }
>>>> </script>
>>>> </head>
>>>> <body>
>>>> </body>
>>>> <html>
>>>>
>>>> You can either load that from a file into the browser widget’s URL or
>>> set its htmlText property accordingly...
>>>>
>>>> Then in LC, make sure you register the httpRequestComplete handler so
>>> that the widget can call it:
>>>>
>>>> set the javascriptHandlers of widget “browser” to “httpRequestComplete”
>>>>
>>>> After that, add a httpRequestComplete handler to the card script to
>>> handle the returned data:
>>>>
>>>> on httpRequestComplete pUrl, pData
>>>>     — pUrl will be the URL requested
>>>>     — pData will be the data returned from the URL requested
>>>> end httpRequestComplete
>>>>
>>>> Lastly, make your async requests....
>>>>
>>>> do (“httpGetAsync(‘http://www.livecode.com’);” in widget “browser”
>>>>
>>>> Since the JavaScript in the browser widget is issuing the requests and
>>> sending the data back to LC, it doesn’t need to display anything related
>> to
>>> it in the browser widget itself - it can be a blank canvas.
>>>>
>>>> Just be aware that the browser widget can cache URLs and there is no
>>> easy way (that I know of?) in LC to clear the browser’s cache... so if
>> you
>>> see very quick responses on a second or subsequent request to the same
>> URL,
>>> it is likely pulling it all from the browser’s cache.
>>>>
>>>> Cheers,
>>>>
>>>> Charles
>>>>
>>>>>> On 16 Mar 2018, at 1:35 pm, Tom Glod via use-livecode <
>>> use-livecode at lists.runrev.com> wrote:
>>>>>>
>>>>>> Great hints there Mike .... thanks alot.  Luckily I'm desktop only
>>> right
>>>>>> now.
>>>>>>
>>>>>> It shouldn't be too long before I sit down to make something that I
>> can
>>>>>> rely on and reuse in future projects.
>>>>>>
>>>>>> Might turn out I will have to hire someone to help which is cool too.
>>>>>>
>>>>>> It only has to be very simple..and does not need to match performance
>>> of
>>>>>> Tsnet.
>>>>>>
>>>>>> Anything more than 1 would be a great start. LOL.
>>>>>>
>>>>>> I will look into the libURL library and then try to guess which way I
>>>>>> should go my first attempt to hack this.
>>>>>>
>>>>>> I'll keep you guys posted on the progress..I think I need a name for
>>> this
>>>>>> little project.
>>>>>>
>>>>>> Thanks you
>>>>>>
>>>>>> Tom
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