Question2Answer Q&A - Recent questions tagged blob

Different avatar Blob size images won't load consistently on HTTP protocol

Sat, 16 Mar 2024 18:05:41 +0000

I know that most websites use HTTPS protocols nowadays, but I've encountered the following bug.

I've noticed that different Avatar Blob sizes won't load consistently to everybody on HTTP protocol.
The weird thing is that for example, a image with "&qa_size=52" might load fine for me on this device, but if I change browsers or change to a different device, that same image won't load, but others will, and vice-versa.

No webpage was found for the web address: http://mywebsite.com/?qa=image&qa_blobid=8419242312434086559&qa_size=52

HTTP ERROR 404

This problem doesn't seem to occur locally on Localhost.
Also, "&qa_size=100" is the only size that seems to be working consistently for everybody.
Caching is also disabled.
On HTTPS seems to be working fine, as if we open my avatar here for example, and give it a random size, this problem doesn't happen.
But if you open this avatar here, and give it a random size (52 for example), it throws out a 404 page.
Tried with different themes and the result is the same.

How to fix Viewport not configured correctly?

Wed, 26 Aug 2020 03:48:48 +0000

I already add viewport in the layout--> head section . But this viewport issue is still remain.How can i fix this issue?

How to set up QA_BLOBS_DIRECTORY correctly?

Mon, 20 Jul 2020 03:50:19 +0000

I'm moving images stored in database to a directory. I created a folder named "blob" inside of my installation folder and change its permissions to 777.

However, I got the error message

The directory /blob/ defined as QA_BLOBS_DIRECTORY is not writable by the web server.

Here's what in the configure file

define('QA_BLOBS_DIRECTORY', '/blob/');

How do I set up in a correct way?

How protect direct 'blob' viewing.

Thu, 10 Dec 2015 00:46:58 +0000

If someone tries to access blob directly, via say a address like:

http://2outof10wouldnotbang.com/?qa=blob&qa_blobid=15199514007654777792

How can i have this redirected to the actual question that this blob was posted in, in the above case,

http://2outof10wouldnotbang.com/34/would-not-bang-in-a-cupboard

I presume this cannot be achieved within .htaccess file, in fact the above is not being picked up by the usualy hotlink protection entries in .htaccess as below:

#Rewrite RUle for Hotlinking
RewriteCond %{HTTP_REFERER} !^http://(.+\.)?2outof10wouldnotbang\.com/ [NC]
RewriteCond %{HTTP_REFERER} !google\. [NC]
RewriteCond %{HTTP_REFERER} !yahoo\. [NC]
RewriteCond %{HTTP_REFERER} !bing\. [NC]
RewriteCond %{HTTP_REFERER} !^$
RewriteRule \.(gif|jpe?g|png|ti?ff|bmp)$ http://2outof10wouldnotbang.com/qa-media/stop_sign.jpg [R,L]

attaching files to questions

Mon, 22 Sep 2014 23:57:22 +0000

i've tried to use few editors , enabled uploading ,

set my blob path to /opt/lampp/htdocs/blob with all permissions.

but...

every time i upload an image only a link appers,

and when i submit a question the link does not exist.

what seems to be the problem?

Change of qa-blob.php for v1.7 (@Scott)

Wed, 16 Apr 2014 11:29:42 +0000

Hi Scott (and Gideon?),

when a PDf is uploaded as Blob and downloaded later on, the current qa-blob.php serves the file only as attachment. This always triggers the download dialog.

The embed plugin with PDF embed cannot work out of the box. The following core hack is necessary:

See from lline 75:

    default:
       $filename=preg_replace('/[^A-Za-z0-9 \\._-]/', '-', $blob['filename']); // for compatibility with HTTP headers and all browsers

       // q2apro hack for embed pdf
       if($blob['format']=='pdf') {
           header('Content-Type: application/pdf');
           header('Content-Disposition: inline; filename="'.$filename.'"');
           break;
       }
       header('Content-Type: application/octet-stream');
       header('Content-Disposition: attachment; filename="'.$filename.'"');
       break;

Can this be included (as an option?) in q2a v1.7?

Thanks,
Kai

Getting the path to image file from qa_blob?

Fri, 01 Nov 2013 07:42:24 +0000

I am testing the new feature "save image to harddrive" instead of blob.

As I see there are folders created in my upload folder defined in QA_BLOBS_DIRECTORY. As it seems these are arbitrary numbers from 000 to 184.

Two questions:

1. What is the mechansim behind the folder numbers?
okay, while writing this post, I found the answer in: function qa_get_blob_directory()
(subdirectories are named by the first 3 digits of $blobid)

2. How can I retrieve the path to the file on the harddisk using qa_blobs table?
This is important as I would like to update my image manager plugin accordingly.

Okay, number 2 can also be solved regarding number 1.

But there is another question now:

3. Why is "849092891028879862.png" saved in folder "008" and not "849" ?

Here is the substring return from function qa_get_blob_directory:
rtrim(QA_BLOBS_DIRECTORY, '/').'/'.substr(str_pad($blobid, 20, '0', STR_PAD_LEFT), 0, 3);

But what is happening here? STR_PAD_LEFT fills zeros to the left, 0, 3 takes the first 3 digits.... ?

Thanks.

subdirectories are named by the first 3 digits of $blobid - Why?

Tue, 15 Oct 2013 11:54:14 +0000

I am just checking the new blob upload features, @gidgreen: good work for the image resizing!

Now I am wondering, why there are folders created for the blobs. see "subdirectories are named by the first 3 digits of $blobid" from function qa_get_blob_directory($blobid) in qa-app-blobs.php

Where is the option to upload images to disk instead database / blob?

Mon, 14 Oct 2013 17:37:10 +0000

I cannot find the postings... I just found the "buttons" graphics: http://www.question2answer.org/qa/24390/tips-upload-file-management-with-v1-6

I'd like to activate and test the feature upload image to server instead database - where is it?

it must be somewhere...

Getting All Blobs From a User?

Fri, 19 Jul 2013 13:54:04 +0000

I'm making a plugin that adds a gallery page where the user can add its own art/images/... . The upload works fine, the blobs have the correct user-id, but now I don't know how I'd fetch all the blobs uploaded by a particular user. How would one do so?

Writing a blob from a plugin

Wed, 17 Jul 2013 13:15:27 +0000

If one wants to write the contents of an image to the database (in the blobs : 'qa_blobs'), how would he do so through PHP?

Special upload area for only Experts - interested in such a plugin?

Sun, 14 Jul 2013 14:14:05 +0000

I think this is an idea for a new plugin...

All my users as well as anonymous can upload images to the forum using the WYSIWYG editor. The upload is restricted to images only.

However, some of my experts create professional documents in PDF format.

1. They should upload their PDFs on a separate page, saved as blob into the blob-db-table (qa_blobs).

2. Every expert should see a list of all uploaded PDFs to get the link from.

3. It would be great to have another filename than domain.com/?qa=blob&qa_blobid=17474948105245553660 maybe something like: domain.com/documents?pdf=17474948105245553660

Anyone likes the idea, and is interested?

Thanks,
Kai

Migrate to disk problem

Sun, 16 Jun 2013 03:21:45 +0000

Hello i am getting this error whin i enabled my blob form config file and when i click to migrate from database to disk it stats and not stops like that 100 of 7 150 of 7 ........ 800 of 7 and so on...

The directory 1 defined as QA_BLOBS_DIRECTORY is not writable by the web server.

Tips: Upload file management with V1.6

Fri, 07 Jun 2013 01:32:37 +0000

The feature that can manage upload file on disk was added to Q2A V1.6. I report usage of this feature.

What?

The file (image) uploaded in CKEditor(etc) was stored to database conventionally, you can choose database or disk from V1.6. Even if you choose disk, URL does not change. In other words, you can access files by old link(old link does not expire). Of course, there is data migration tool, too.

Where?

Setting: qa-config.php define('QA_BLOBS_DIRECTORY', ...
Button: admin -> stats -> "Blobs to disk"
Button: admin -> stats -> "Blobs to database"

2 & 3 buttons nothing in my Q2A...

2 and 3 buttons are displayed on following condition.

button2: 1 is enable. AND data exit in database.
button3: 1 is enable. AND file exist in folder1.

Which?

This is just guideline.

People who wants to keep database smaller should choose disk.
People who wants to make everyday backup only database should choose database.

Safety?

Because Q2A get from file system if data don't exist in database, even if you change destination, it is OK.

Last: necessary inspection

I don't yet know whether image access performance is improved by disk mode.

I'm glad if helpful to someone.

My hope about qa_db_blob_read() at 1.6dev

Fri, 17 May 2013 03:40:06 +0000

I try to use qa1.6-0512.

qa_db_blob_read() in qa-include/qa-db-blobs.php

If QA_BLOBS_DIRECTORY is defined, I hope to get contents by calling file_get_contents() at qa_db_blob_read(). At new version, since file_get_contents() called at qa_read_blob() in qa-include/qa-app-blobs.php, Core is no problem. But, back compatibility cannot be maintained.

Please, please, consider users / plugins of using low level function.

Best regards.

About PNG image created in qa_blob table

Wed, 01 May 2013 04:51:15 +0000

I would like to process rounded corners avatar image(Alfa-channel PNG). The PNG registered into qa_blob table is displayed by JPEG. Is it difficult to display according to PNG format?

How to use q2a-embed plugin (NoahY) to embed q2a-uploaded image with blobid?

Thu, 16 Aug 2012 07:12:26 +0000

sometimes it happens that a user uploads an image and another user wants to use this image in his new post.

Problem: He has to upload the image again to put it into his post.

The embed plugin of NoahY considers (png|jpg|jpeg|gif|bmp) -> however, the URL of the uploaded image in q2a looks like that:

http://www.gute-mathe-fragen.de/?qa=blob&qa_blobid=13189400781078488791

Can somebody tell me how I should change the qa-embed-layer.php of the embed plugin to achieve parsing this blob as an image as well?

Line 52 of qa-embed-layer.php:

'image'=>array('(https*:\/\/[-\%_\/.a-zA-Z0-9]+\.(png|jpg|jpeg|gif|bmp))[^< ]*','<img src="$1" style="max-width:'.$w2.'px;max-height:'.$h2.'px" />','img'),

what should be the new regex??

Note 1: All my uploads are images! So every blobid is an image.
Note 2: I changed the CKEditor - so there is no URL field for images anymore.

Modifying qa_db_blob_create() ?

Wed, 16 May 2012 20:38:19 +0000

Does somebody know how to modify the function qa_db_blob_create() in qa-db-blobs.php that way that it stores the original image under same blobid name with imageextension as well to a folder ? (Received from qa-wysiwig-upload.php line 110 )

If at least that is possible, one can get hands on that image through the id and use any tool to modify it.

That would help as long there is no complete plugin to store images in the filesystem or plugin for advanced image handling and as it still would be as well in the database there wouldnt be problems to upgrade once a plugin is available.

Thanks in any case...

Does anybody know here how to store a blob image as normal image ?

Wed, 16 May 2012 16:46:15 +0000

I am still trying to get thumbnails or resized images to avoid very slow loadingtimes for firt time visitors of my pages.

Timthumb, phpthumb, slir all do a good job but not with blobimages as source !

Any hint is welcome.

How to remove unused images from database (blob)?

Tue, 08 May 2012 13:24:20 +0000

How to remove unused images from database (blob)? To save space in database and keep up performance.

Is there any mysql query that can do this?