On Mon, 2023-02-13 at 04:13 +0000, Ashley Sheridan wrote:
> On 13/02/2023 03:35, John Iliffe wrote:
> > On Sun, 2023-02-12 at 22:41 +0000, Ashley Sheridan wrote:
> > > On 12/02/2023 22:29, John Iliffe wrote:
> > > > On Sun, 2023-02-12 at 21:15 +0000, Ashley Sheridan wrote:
> > > > > On 12/02/2023 19:49, John Iliffe wrote:
> > > > > > I seem to be getting extraneous data in the response sent to the browser by PHP.
> > > > > >
> > > > > > The server query is an AJAX request in json format which is received and
> > > > > > processed correctly and the result is sent using the "echo" function. I have
> > > > > > checked and the area where the response is constructed is empty when processing
> > > > > > starts.
> > > > > >
> > > > > > The data received by the browser has BOTH the request json data followed by the
> > > > > > correct response in the received string (result not HTML, just a string that
> > > > > > will eventually be converted to json but so far will only be caught in the
> > > > > > browser for display).
> > > > > >
> > > > > > I'm using XMLHttpObject in the browser and I haven't been able to find a way to
> > > > > > separate the request from the response. Before I construct an elegant
> > > > > > workaround does POST normally return the request? If not, what am I doing
> > > > > > wrong? So far I have always used GET so I know it doesn't return the request.
> > > > > >
> > > > > > For completeness, here is what the server says it is sending to the browser
> > > > > > (using echo) (The json may be wrong; I'm still just trying to receive it).
> > > > > >
> > > > > > ------
> > > > > > sent to browser:
> > > > > > "jres":[{"item_id":"5","i_type":"OL","i_name":"Student Success
> > > > > > Pages","i_stock":"99924","i_price":"14.00","i_books_box":"0"},{"item_id":"13","i
> > > > > > _type":"CD","i_name":"Basic Instructors Guide 9th
> > > > > > Ed.","i_stock":"9983","i_price":"19.95","i_books_box":"0"},{"item_id":"20","i_ty
> > > > > > pe":"SG","i_name":"Canadian Amateur Radio Basic Qualification Study
> > > > > > Guide","i_stock":"274","i_price":"44.95","i_books_box":"20"},{"item_id":"21","i_
> > > > > > type":"SG","i_name":"Canadian Amateur Radio Advanced Qualification Study
> > > > > > Guide","i_stock":"1586","i_price":"49.95","i_books_box":"16"}]
> > > > > > -----
> > > > > >
> > > > > > here is the original request from the browser, as decoded by server
> > > > > > ------
> > > > > > request method: POST
> > > > > > requests: array (
> > > > > > 'req' => '{"func":"act","item":"438"}',
> > > > > > )
> > > > > >
> > > > > > json last error message: No error
> > > > > > decoded_args:
> > > > > > func=act
> > > > > > item=438
> > > > > >
> > > > > > -------
> > > > > >
> > > > > > and here is what the browser says it received back:
> > > > > >
> > > > > > -----
> > > > > > received:-->array(2) {
> > > > > > ["func"]=>
> > > > > > string(3) "act"
> > > > > > ["item"]=>
> > > > > > string(3) "438"
> > > > > > }
> > > > > >
> > > > > > "jres":[{"item_id":"5","i_type":"OL","i_name":"Student Success
> > > > > > Pages","i_stock":"99924","i_price":"14.00","i_books_box":"0"},{"item_id":"13","i
> > > > > > _type":"CD","i_name":"Basic Instructors Guide 9th
> > > > > > Ed.","i_stock":"9983","i_price":"19.95","i_books_box":"0"},{"item_id":"20","i_ty
> > > > > > pe":"SG","i_name":"Canadian Amateur Radio Basic Qualification Study
> > > > > > Guide","i_stock":"274","i_price":"44.95","i_books_box":"20"},{"item_id":"21","i_
> > > > > > type":"SG","i_name":"Canadian Amateur Radio Advanced Qualification Study
> > > > > > Guide","i_stock":"1586","i_price":"49.95","i_books_box":"16"}]<--
> > > > > > -----
> > > > > >
> > > > > > Thanks in advance for any suggestions you can give.
> > > > > >
> > > > > > John
> > > > > > ======
> > > > > Hi John,
> > > > >
> > > > > What does your PHP code look like? Something in it must be outputting
> > > > > the request, as that's not something that would just occur all by itself.
> > > > >
> > > > > Regards,
> > > > > Ash
> > > > Thanks for the quick response Ash. That's what I have been asking myself and I
> > > > wondered if returning the query is a requirement of the POST protocol. Without
> > > > sending the entire script, I can say that there are only two "echo" statements
> > > > in it (by doing a grep for echo) and they are mutually exclusive:
> > > >
> > > > -----
> > > > [John@prod04 test]$ grep -n echo ./XXXXXXb.php
> > > > 140: echo $json_resp;
> > > > 145: echo "<br />XXXXXb: Either func or item was not set<br />err is true,
> > > > errno=" . $errno . "<br />";
> > > > -----
> > > > <?php
> > > > ob_start();
> > > > /* XXXXXXb responds to AJAX inventory report requests
> > > > * from updated XXXXXXXX.
> > > > *
> > > > * Written J Iliffe 2/2023
> > > > * copyright John Iliffe, 2023, all rights reserved.
> > > > */
> > > > //header('Content-Type: application/json; charset=utf-8');
> > > > header('Content-Type: text/plain; charset=utf-8');
> > > > $func = "";
> > > > $item = 0;
> > > > $err = false;
> > > > $errno = 0;
> > > >
> > > > $fx = fopen("/tmp/XXXXXb.txt","w");
> > > >
> > > > fwrite($fx,("\nrequest method: " . $_SERVER['REQUEST_METHOD']));
> > > > fwrite($fx,("\nrequests: " . var_export($_REQUEST,true)));
> > > >
> > > > /* get the json request block as associative array */
> > > > if (isset($_POST['req']))
> > > > {
> > > > $decoded_args = json_decode($_POST['req'],true,5,JSON_INVALID_UTF8_IGNORE);
> > > >
> > > > if ((isset($decoded_args['func'])) && (isset($decoded_args['item'])))
> > > > {
> > > > $func = $decoded_args['func'];
> > > > $item = $decoded_args['item'];
> > > > fwrite($fx,("\nfunc and item isset as " . $func . " and " . $item .
> > > > "\n"));
> > > > }
> > > > else
> > > > {
> > > > $err = true;
> > > > $errno = 2;
> > > > }
> > > >
> > > > fwrite($fx,("\njson last error message: " . json_last_error_msg() .
> > > > "\n"));
> > > > fwrite($fx,("decoded_args:" . var_dump($decoded_args) . "\n"));
> > > > fwrite($fx,("func=" . $decoded_args['func'] . "\n"));
> > > > fwrite($fx,("item=" . $decoded_args['item'] . "\n"));
> > > > }
> > > > else
> > > > {
> > > > $err = true;
> > > > $errno = 1;
> > > > }
> > > >
> > > > /* if we are good to go here, open database, create query */
> > > > $json_resp = '"jres":['; //json opening
> > > >
> > > > ----I deleted the database activity from here---
> > > >
> > > > if (! $err)
> > > > {
> > > > if (! $res)
> > > > {
> > > > $err=true;
> > > > $errno = 4;
> > > > }
> > > > else
> > > > {
> > > > for ($i=0;$i<$rows;$i++)
> > > > {
> > > > $r_arr = pg_fetch_array($res,null,PGSQL_ASSOC);
> > > >
> > > > $json_rec=json_encode($r_arr,0,16);
> > > >
> > > > if ($json_rec === false)
> > > > {
> > > > fwrite ($fx,("\nrecord at " . $i . " bad, " .
> > > > json_last_error_msg() . "\n"));
> > > > }
> > > >
> > > >
> > > > if (($i < $rows) && ($i != 0)) // no opening or trailing ','
> > > > {
> > > > $json_resp .= ',';
> > > > }
> > > >
> > > > $json_resp .= $json_rec;
> > > > }
> > > >
> > > > $json_resp .= ']';
> > > >
> > > > fwrite($fx,("\njson sent to browser:\n -->" . $json_resp . "<---\n\n\n"));
> > > > }
> > > > }
> > > > }
> > > >
> > > > if (! $err)
> > > > {
> > > > echo $json_resp;
> > > > ob_flush();
> > > > }
> > > > else
> > > > {
> > > > echo "<br />adm9005b: Either func or item was not set<br />err is true,
> > > > errno=" . $errno . "<br />";
> > > > ob_flush();
> > > > }
> > > >
> > > > exit;
> > > > ?>
> > > > ------
> > > >
> > > > This is pretty much what I have so far and why it has been driving me nuts for
> > > > several days now...the query is never repeated anywhere in the echoed output.
> > > > What actually comes back to the browser, as you can see above, is is the result
> > > > generated by this; prepended with PHP's analysis of the original POST query.
> > > >
> > > > Thanks for taking the time to look.
> > > >
> > > > John
> > > > ======
> > > It might be some error output, which is being supressed by the
> > > ob_start(), and then output when you do the ob_flush(). Why are you
> > > using those, as it's unusual for what you appear to be doing here.
> > >
> > > Thanks,
> > > Ash
> > >
> > Thanks for the suggestion Ash. I commented out the ob_start and ob_flush
> > statements but the problem persists.
> >
> > I was using buffering because I have to send headers as part of the response, at
> > the very least the content-type header when I convert the response to json. The
> > reason it is a simple string at the moment is that I didn't want my inexperience
> > with json to get involved with getting the communications working properly.
> >
> > Regards,
> >
> > John
> > ======
>
> Have you tried attaching a debugger, to see at what point the extra
> output is being shown? Is it being added to the response variable
> somewhere, possibly from the code that you removed from your excerpt?
>
> Also, you don't need to use object buffers if you're sending headers.
> Typically, you'd use output buffering if you wanted to prevent something
> from making it to the final output, or if you needed to control the
> output during a streamed response.
>
> Thanks,
> Ash
=======
Thank you Ash. As it turned out, the note from Janis has the answer, var_dump
outputs rather than returning a value so it was doing a sort of a phantom "echo"
in the background. Sorry to have wasted your time.
Also, thanks very much for the comments of the output buffering. I read
somewhere that if it was necessary to send headers then I have to buffer the
output to avoid having any html sent before the headers and I, mistakenly,
assumed that I would have to do that here, even though no html is being sent.
Works properly without buffering so I will delete that. That, I suppose, is the
result of learning while doing! (I'm the only one here that works on the
server, and I'm also the sysadmin, operator, and network guy)
Regards, and thanks,
John
======
