Error thrown when generating WP thumb for PDF

Thanks for your report and for taking the time to try the experiment suggested in the earlier topic. I haven’t been able to reproduce your issue on my system so I’d like to ask for more information.

My suspicion is that the PDF item you are starting from does not have an “attachment metadata” array, which is causing the problem on line 356. To investigate that, can you find one of the items in the Media/Assistant table and click the “Edit” rollover action to get the Edit Media screen. Then scroll down and see if there is an “Attachment Metadata” box between the “Parent Info” and “Menu Order” boxes. If not, let me know. If there is one, can you post the content?

It would also help if you could activate MLA logging, try the generation again and let me know what the logging shows. To turn on logging:

1. Navigate to the Settings/Media Library Assistant Debug tab.
2. Enter “0x8” in the MLA Reporting text box. That activates MLA debug logging for the thumbnail generation logic.
3. Click the “Save Changes” button to record the new setting.

Any additional information you can provide will be helpful. If the log is too big to post, contact me at my web site and I will give you instructions for sending the log file. Thanks!

Hi, first let me say that the support I get for this plug-in probably the best plugin support I have ever experienced. Thank you.

This is what is in the Attachment Metadata box : ‘A’ (including the quotes)

here is the log:
[20-Sep-2019 13:37:58] 601 MLACore::mla_plugins_loaded_action() MLA 2.80 () mla_debug_level 0x9
[20-Sep-2019 13:38:13] 601 MLACore::mla_plugins_loaded_action() MLA 2.80 () mla_debug_level 0x9
[20-Sep-2019 13:38:13] 388 MLA_Thumbnail::mla_list_table_custom_bulk_action image_downsize( 1166 ) thumbnail = false
[20-Sep-2019 13:38:13] 407 MLA_Thumbnail::mla_list_table_custom_bulk_action get_post_thumbnail_id( 1166 ) thumbnail = ”
[20-Sep-2019 13:38:13] 339 MLAImageProcessor::mla_handle_thumbnail_sideload( /home/draytonc/public_html/wp-content/uploads/2019-09-15-weekly-newsletter.pdf ) args = array (
‘type’ => ‘WordPress’,
‘existing_thumbnails’ => ‘delete’,
‘suffix’ => ‘-Thumbnail’,
‘best_fit’ => false,
‘clear_filters’ => false,
)
[20-Sep-2019 13:38:13] 452 MLAImageProcessor::mla_handle_thumbnail_sideload( /home/draytonc/public_html/wp-content/uploads/2019-09-15-weekly-newsletter.pdf ) results = array (
‘name’ => ‘2019-09-15-weekly-newsletter.pdf’,
‘type’ => ‘image/jpeg’,
‘tmp_name’ => ‘/tmp/2019-09-15-weekly-newsletter-T7VJP9.tmp’,
‘error’ => 0,
‘size’ => 326952,
‘width’ => 1088,
‘height’ => 1408,
)
[20-Sep-2019 13:38:13] 335 MLA_Thumbnail::_generate_wordpress_thumbnail( 1166, /home/draytonc/public_html/wp-content/uploads/2019-09-15-weekly-newsletter.pdf ) sideload results = array (
‘file’ => ‘/home/draytonc/public_html/wp-content/uploads/2019-09-15-weekly-newsletter-pdf-4.jpg’,
‘url’ => ‘https://draytoncrc.org/wp-content/uploads/2019-09-15-weekly-newsletter-pdf-4.jpg’,
‘type’ => ‘image/jpeg’,
)
[20-Sep-2019 13:38:13] 357 MLA_Thumbnail::_generate_wordpress_thumbnail item_data = ‘A’
[20-Sep-2019 13:38:18] 601 MLACore::mla_plugins_loaded_action() MLA 2.80 () mla_debug_level 0x9

Interestingly I only get this error with PDFs generated out of Microsoft publisher, which my client uses extensively. For example when I go into Microsoft word and generate a test document and save it as PDF, it uploads fine. Is it possible that Microsoft publisher is not setting the metadata for the file correctly?

Interestingly I only get this error with PDFs generated out of Microsoft publisher, which my client uses extensively. For example when I go into Microsoft word and generate a test document and save it as PDF, it uploads and generates the thumbnail fine. Is it possible that Microsoft publisher is not setting the metadata for the file correctly?

Thank you for the additional information, for running the test and posting the log information; very helpful. It’s quite possible that Microsoft Publisher is part of the problem; it has been in the past. It looks like your issue is a variation on the one reported in this earlier topic:

PDF thumbnail generation fails with error message

Based on the URL in your log file information I was able to fetch a copy of your “2019-09-15-weekly-newsletter.pdf ” document and upload it to my test system. I did not get the PHP Warning or the corrupted attachment_metadata but the thumbnail image generated by WordPress during the upload had the “somber black” content instead of the page content. Regenerating the thumbnail in MLA solved that problem.

Can you either verify that the document I fetched is the one generated by Microsoft Publisher or, if not, post a link to one or more of the documents that aren’t working for you? I would like to investigate the metadata problem further before creating a fix. Thanks for your persistence and your help!

Hi David, yes the one you fetched is a good example of ones that fail for me.
Thanks!
Irving

Thanks for confirming that the document I downloaded is a good test case.

The 'A' values you report are a consequence of the “Warning: Illegal string offset” issue when MLA tries to generate thumbnails. It would be interesting to upload a fresh copy of the document on your system and then look at the Attachment Metadata content before trying the MLA thumbnail generation. I don’t get this issue on my system.

In any case, I have updated the MLA code to replace the invalid metadata with valid data, which will “associate” the generated thumbnails back to the PDF document item.

I have uploaded a new MLA Development Version dated 20190923 that contains the fix. You can find step-by-step instructions for using the Development Version in this earlier topic:

PHP Warning on media upload with Polylang

It would be great if you can install the Development Version and let me know if it works for you. Thanks for your help and persistence.

Hi David, I have tested version 20190923 , and it successfully adds the WP thumb, without throwing error, so thanks!

FYI, when I upload a fresh copy of the document, the is NO ‘Attachment Metadata’ box shown at all.

Thanks for confirming the fix and for taking the time to try uploading a fresh copy of the document. As I suspected, on your system the WordPress process for thumbnail generation fails, leaving the attachment_metadata completely empty. When you tried using MLA generation with the older MLA version, the empty metadata caused MLA to put the invalid 'A' value in the metadata field. The MLA development version corrected that problem.

I do not know why WordPress generation fails and MLA generation works; your system behaves differently from mine. As I wrote earlier, on my system the WordPress thumbnail is generated but has corrupt content (solid black content). That’s similar to the symptoms reported in the earlier topic I referenced.

Are there any messages in your error log that might be related to the failed WordPress generation attempt? I am still looking for the cause of that problem.

It has been over a month since my last post. I am marking this topic resolved, but please update it if you have any further issues or information regarding the failed PDF thumbnail generation on your system.