I'm working on a simple script in a custom theme in Drupal 7 that is supposed to just rotate through different background image each time a user loads the page. This is my code in [view].tpl.php that picks which image to use.
$img_index = (!isset($_SESSION["img_index"]) || is_null($_SESSION["img_index"])) ? 1 : $_SESSION["img_index"] + 1;
if ($img_index > 2) {
$img_index = 0;
}
$_SESSION["img_index"] = $img_index;
Pretty simple stuff, and it works fine as long as Drupal starts up a session. However, if I delete my session cookie, then always shows the same image, a session is never started.
I'm assuming that since this code is in the view file that the view code is being cached for anonymous users and hence the session is never started, but I can't figure out how to otherwise do what I want.
Don't mess with session like /u/maiznieks mentioned on Reddit. It's going to affect performance.
I've had to do something similar in the past and went with an approach like /u/maiznieks mentions. It's something like this,
Return all the URLs in an array via JS on Drupal.settings.
Check if a cookie is set.
If it's not, set it and set it's value to 0.
If it's set, get the value, increase the value by one, save it to the cookie.
With that value, now you have an index.
Check if image[index] exists
If it does, show that to the user.
If it doesn't, reset index to 0 and show that. Save 0 to the cookie.
You keep caching. You keep showing the user new images on every page load.
You could set your current view to do a random sort every 5 mins. You would then only have to update the logic above to replace that image. That way you can keep something similar working for users with no JS but still keep this functionality for the rest.
You can replace cookies above with HTML5 local storage if you'd like.
#hobberwickey, I will suggest to create a custom module and implement hook_boot() in module. As per drupal bootstrap process session layer will call after cache layer everytime. hook_boot can be called in cache pages and before bootstrap process also. You can take more information here.
Related
I am using AWS S3 with Rails 7 to store images via Active Storage. I'm presenting my data to the view by querying Elasticsearch (using the elasticsearch-model gem).
While this works great for my other data, the expiration of the signed AWS URL becomes an issue after a little while and the images are of course no longer accessible.
class MyClass
has_one_attached :image
end
I'd like to be able to have a fresh URL and still use Elasticsearch so that I don't need to make a trip to the database every time I want to see the image.
I have looked up whether I can just remove the expiration however I've read that it's unsafe and mostly unsupported. I know that Elasticsearch::Model callbacks exists but I'm not clear on whether that could be applied to ActiveStorage::Blob, especially since nothing changes in the DB when the expiration occurs.
I've also thought about just changing the URLs to expire at 1 week via passing in the expires_in param to the url method on the attachement and then performing a chon job to update the image once a week. Seems hacky though.
I'm sure there are many ways to approach this but what worked for me was using the save callback on an async job when the model that contains the Elasticsearch::Model. When this particular attribute was updated, I called a job with a delay just before the maximum signed_url time allowed by s3 which is 7 days.
after_save :set_refresh_url_job, if: Proc.new { logo_url? }
def set_refresh_url_job
RefreshLogoUrlJob.
set(wait: MyModel::LOGO_EXPIRTY_REFRESH).
perform_later(self)
end
Longtime D7 user, first time with D9. I am writing my first custom module and having a devil of a time. My routing calls a controller that simple does this:
\Drupal::service('page_cache_kill_switch')->trigger();
die("hello A - ". rand());
I can refresh the page over and over and get a new random number each
time. But, when I change the code to:
\Drupal::service('page_cache_kill_switch')->trigger();
die("hello B - ". rand());
I still get "hello A 34234234" for several minutes. Clearing the cache doesn't help, all I can do is wait, it's normally about two minutes. I am at my wits end.
I thought it maybe an issue with my docker instance. So I generated a simple HTML file but if I edit then reload that file changes are reflected immediately.
In my settings.local.php I have disabled the render cache, caching for migrations, Internal Page Cache, and Dynamic Page Cache.
In my mymod.routing.yml I have:
options:
_admin_route: TRUE
no_cache: TRUE
Any hint on what I am missing would be deeply appreciated.
thanks,
summer
I have a scheduled script execution that needs to persist a value between runs. It is updated with each run. Using gs.setProperty seemed like the natural place until I came across this:
Care should be taken when setting system properties (sys_properties)
using this method as it causes a system-wide cache flush. Each flush
can cause system degradation while the caches rebuild. If a value must
be updated often, it should not be stored as a system property. In
general, you should only place values in the sys_properties table that
do not frequently change.
Creating a separate table to store a single scalar value seems like overkill. Is there a better place to store it?
You could set a preference if you need it in the instance. Another place could be the events table. Log the event with the data in parm1 or parm2 and on next run query the most recent event.
I'd avoid making a table as that has cost implications for some clients. I agree with the sys_properties.
var encrypter = new GlideEncrypter();
var encrypted = encrypter.encrypt('Super Secret Phrase');
gs.info('encrypted: ' + encrypted);
var decrypted = encrypter.decrypt(encrypted);
gs.info('decrypted: ' + decrypted);
/**
*** Script: encrypted: g/bXLJHa7xNRMKZEo5q/YtLMEdse36ED
*** Script: decrypted: Super Secret Phrase
*/
This way only administrators could really read this data. Also if I recall correctly, the sysevent table is cleared after 7 days. You could have the job remove the event as soon as it has it in memory.
One of the main purposes of caching is to save resources and not do things like hit your database every request. In light of this, I'm confused by what all Codeigniter does in a controller when it encounters a cache() statement.
For example:
$this->output->cache(5);
$data=$this->main_model->get_data_from_database();
$this->load->view("main/index", $data);
I realize that the cached main/index html file will show for the next 5 minutes, but during these 5 minutes will the controller still execute the get_data_from_database() step? Or will it just skip it?
Note: the Codeigniter documentation says you can put the cache() statement anywhere in the controller function, which confuses me even more about whats getting executed.
I can answer my own question. NOTHING in the controller function other than the cached output gets executed during the time in which the cache is set.
To test this yourself, do a database INSERT or something that would be logged somehow (e.g. write to a blank file).
I added the following code below my cache() statement and it only inserted into the some_table table the first time I loaded the controller function and not the 2nd time (within the 5 minute span).
$this->db->insert('some_table', array('field_name' => 'value1') );
I think this can be verified enabling the Profiler in your controller and check if any query is done. Make sure this is enabled only for your IP if you're using it in Production environment.
$this->output->enable_profiler(TRUE);
-- EDIT 1 --
This will be visible only once. Soon after the cached page is stored, the profiles result won't be visible again (so you might wanna delete the file and refresh the page).
-- EDIT 2 --
You might also use:
log_message('info', 'message');
inside your model, then change in config.php, $config['log_threshold'] to 3 and check the log file.
-- EDIT 3 --
For sure the selection will be done unless you have enabled the database cache. In this case, in the cache folder you'll see the database selection cached.
I have a webservice that stores an authenticated users token in the HttpRuntime.Cache to be used on all subsequent requests. The cached item has a sliding expiration on it of 24 hours.
Secondly I have a vb.net app that is pinging this webservice every 15 seconds. It gets authenticated once, then uses the cached token for all subsequent requests. My problem is that the application appears to lose authentication at random intervals of time less than the 24 hr sliding expiration. However with it getting pinged every 15 sec the authentication should never expire.
I am looking for a way to view the HttpRuntime.cache to try and determine if the problem is in the webservice security methods or within the vb.net app. Can I view the HttpRuntime.cache somehow?
The webservice is part of a web forms site that was built with asp.net 2.0 on a Windows Server 2008.
The name of my key's were unknown as they were system generated guid values with a username as the value. So in order to view a cache collection that was unknown I used a simple loop as follows.
Dim CacheEnum As IDictionaryEnumerator = Cache.GetEnumerator()
While CacheEnum.MoveNext()
Dim cacheItem As String = Server.HtmlEncode(CacheEnum.Entry.Key.ToString())
Dim cacheItem2 As String = Server.HtmlEncode(CacheEnum.Entry.Value.ToString())
Response.Write(cacheItem & ":" & cacheItem2 & "<br />")
End While
Hope this helps others.
First off, HttpRuntime.Cache would not be the best place to store user authentication information. You should instead use HttpContext.Current.Session to store such data. Technically the cache is allowed to "pop" things in it at its own will (whenever it decides to).
If you actually need to use the cache, you can check if your item is in the cache by simply doing:
HttpRuntime.Cache["Key"] == null