You can inspect the maybe faulty response coming from php by using the web dev console (Ctrl + i). In the network tab is the async call from ajax with its response. Or did you do this already?
Additionally xdebug dumps php errors in a little nicer format.
JEFFRY KILLEN <jekillen@xxxxxxxxxxx> schrieb am Di., 10. Aug. 2021, 20:13:
> On Aug 10, 2021, at 10:19 AM, Ashley Sheridan <ash@xxxxxxxxxxxxxxxxxxxx> wrote:
>
>
> On 10/08/2021 17:43, JEFFRY KILLEN wrote:
>>
>>> On Aug 10, 2021, at 12:12 AM, Ashley Sheridan <ash@xxxxxxxxxxxxxxxxxxxx> wrote:
>>>
>>>
>>>
>>> On 10 August 2021 01:36:01 BST, JEFFRY KILLEN <jekillen@xxxxxxxxxxx> wrote:
>>>> Hello;
>>>>
>>>> I have a web page I am developing.
>>>>
>>>> It has images embedded in it.
>>>>
>>>> The src attribute is ./?tag=guitar&type=img
>>>>
>>>> The php code from the html file is:
>>>> </php
>>>> // preliminary irrelevant code
>>>> require_once('php/imageServer.php');
>>>>
>>>> if($_GET['tag'])
>>>> {
>>>> //// file_put_contents('test.txt', "Hello?...img...");
>>>> /*
>>>> the following was working before I expanded it out to running code as written.
>>>> it still should work.
>>>> (new _IMG_SERV())->serv($_GET);
>>>> */
>>>> $_x = new _IMG_SERV();
>>>> $_x->serv($_GET);
>>>> }
>>>> ?>
>>>>
>>>> the serv method in the class is
>>>>
>>>> public function serv($_a)
>>>> {
>>>> file_put_contents('test.txt', "Hello?...img...");
>>>> switch($_a['type'])
>>>> {
>>>> case 'img':
>>>> header('Content-Type: image/jpeg');
>>>> imagedestroy(imagejpeg(imagecreatefromjpeg(self::$_imgDir.self::$_imgIndex[$_a['tag']])));
>>>> break;
>>>> case 'txt':
>>>> if(file_exists(self::$_imgDir.self::$_txtIndex[$_a['tag']]['img']))
>>>> {
>>>> header('Content-Type: image/jpeg');
>>>> imagedestroy(imagejpeg(imagecreatefromjpeg(self::$_txtIndex[$_a['tag']]['img'])));
>>>> }
>>>> else
>>>> {
>>>> /*
>>>> create text image, save for future ref and serve
>>>> */
>>>> }
>>>> break;
>>>> }
>>>> }
>>>>
>>>> This HAS all been working up to a point. BUT the serv function is now refusing to run.
>>>> There are no php, _javascript_ or html related errors.
>>>>
>>>> You will see 'file_put_contents('test.txt', "Hello?...img...");'
>>>> Because this is an async request for a resource I cannot use print or echo to sample
>>>> code progress. So I have strings written to a text file. The call to file_put_contents('test.txt', "Hello?...img...");
>>>> in the top of the serv method is not running. It IS running in the top of the get conditional in the index page
>>>> if I uncomment it.
>>>>
>>>> Does anyone know why apache and/or php, and/or possibly the browser would fail to serve a resource
>>>> like this when it so far has been working most of the day today? I cannot see anything I have done wrong.
>>>> data:
>>>> MacOS High Sierra, apache on localhost
>>>> Thank you for time and attention;
>>>> JK
>>> You say there are no errors, but presumably that just means none being displayed? Have you looked at the error logs?
>>>
>>> Also, the imagedestroy calls here aren't really necessary, as you should be exiting immediately after outputting the image data.
>> I don't have my server set up to log errors. It is a dev server on local host.
>> I use Firefox as dev/test browser. It has dev tools, one of which is network.
>> The requests for image resources represented by the get queries are returning
>> 200, ok. and the image is not displayed. Only the alt string is displayed.
>>
>> However I did make some subtile changes just before the problem appeared. I am going to roll back those
>> changes and see what happens. The changes should not be invalid. It just amounts to when the php script
>> has a full version of resource path.
>>>> self::$_imgDir.self::$_imgIndex[$_a['tag']]
>> Where self::@_imgDir is a string representing the directory location
>> and self::$_imgIndex[$_a['tag']] is the file name.
>> I used to have the complete path/file name in self::$_imgIndex.
>> self::$_imgIndex is set with the contents of an external php script that is required by the class __construct method.
>>
>> Thank you for time and attention
>> JK
>
> Turn on error logs locally, they're absolutely essential for local development. There's also a pretty good case to turn on the display of errors locally too (which is different from error logging to a log file).
>
> As for the image, you say you see the alt text, but you shouldn't see that if you're requesting only the image, as the alt attribute it part of the HTML, and you can't send mixed content via the same request with PHP that I'm aware of.
>
> --
> Ashley Sheridan
> https://www.ashleysheridan.co.uk
I do get php error displayed locally. But not for async requests in the usual manner.
The alt attribute of the img tag is html. It is what is displayed if the image does
not arrive at the browser, as in case the server cannot find the file. Or in this
case the image is not being sent. The image is not being sent because the
serv method is being blocked from executing.
if the php interpreter is doing background security audits why did it take so
many test runs for it to decide the code was insecure or otherwise objectionable?
I did roll back the subtile changes mentioned in my earlier response with no improvement.
When I work with 'ajax' async requests often errors generated by php are included
in the response and are not displayed in lew of the html. So logging would
capture these errors?
Thank you for your responses;
JK
