Singleton pattern with private static reference variable

In the singleton model, the reference variable is declared as a private static variable. So what is the point of declaring this reference variable as a private static reference variable?

php – Is there a way to call the extended functions of the extended class as a static type even if they are not?

I'm trying to reach the class of queries created by the top user defined template class, but I can not do it one way or another .

I want to call the query builders from a user-defined template, as in Laravel.

User :: where (age, & # 39;<', '19')
->bla () -> bla ();

My structure is;
Root model file

The Model class extends MySqlQueryBuilder


Root Query Generator

MySqlQueryBuilder class extends Connector implements QueryBuilder
public function select (string $ table = "", array $ fields = [])

Defined by the user, at the top of the Model class, just an example.

User class extends the model

public service test ()
die (print_r (Model :: select ("table", "field") -> get ()));



Here you can see that I am using the b query. of & # 39; Model & # 39; but no 'User'. it says> Use $ this when it is not an object context.

What I miss, can someone help me?

Static and crackling noise coming from the speakers in 19.04

I've recently made a new installation of Ubuntu 19.04 and my speakers are constantly emitting static cracklings. I did not have this problem in 18.10. The static sound disappears for a second when I change the volume and there is no sound when I mute the sound completely.

Static cell-click to open pdf file? xcode + swift

I am new enough to go fast but I learn quickly. In this case, I created a table view with sections made up of static cells. I have created these tables via the interface generator, so there is no UItableviewcontroller file.

I would like to create an action for when a particular static cell is touched to display a file in a new view controller.

I linked the new view controller to the table and placed a UIView on it to render the PDFKit pdfview. How to create the action to open different (local) pdf files in the single view controller when the particular cell is selected?

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(p.s.I have about 20 pdf files that will need to be displayed, I do not wish to create multiple view controllers for each pdf file.)

error – The admin panel of Magento2.2.5 fails to access cms page or static blocks

When I go into the admin panel and try to get a cms page or a static block (in the admin panel), I get a 500 error that is the error below. Similarly, in the admin panel, if the error I am trying to reach is a basket price rule, the error below occurs.

Also on the site, when you access a category, the image of the top category does not seem to load.

When I look in the server logs, I see the error
Uncaught exception "Error" with message "Unable to instantiate Magento Framework Config ReaderInterface interface" in /vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php:11

Computer Networks – Static Routing in the Cisco Packet Tracer

I work in a Cisco packet tracer tool. Configuring the router statically. I searched the net but I did not find the solution. When I connect my router0 to router3 enter the description of the image here
By giving the command "ip route"
What will be the last known network that will be used at the end of this command

Amazon Web Services – How static / elastic IP addresses work, and more specifically why they need an address by "region"

I'm looking at Google Cloud and AWS and when you select "reserve static IP address", you need to specify a region like us-east-1, and so on. I understand that the regions are different data centers, but I am not. know what is the process for IP addresses used with regard to domain names ….

Specifically, let's say you have a website such as I wonder how this is mapped to a static IP address, or even if it must be static and can be dynamic.

What I imagine up to now, is that there is a 1-1 correspondence between the IP address and the domain name. So can be mapped to the world's only public static IP load balancing to distribute it to a group of servers.

But what's missing from this understanding is knowing where the regions come in. If I want to "take care of different regions", so that requests are processed more quickly, I would imagine that servers would work in a region specific. These servers are all processing the domain request But what I do not understand, if there are multiple IP addresses (static IP addresses I guess), any mapping to the same domain, how does the thing choose which IP address to use. You wonder if it is physically based on interconnected systems. So, my request on my laptop for go on my side to the WAN in the nearest area, saying, "Oh, I have to go to for the eastern region, not for the western region." Then the request is handled by local and other servers. I receive this final part.

What I miss is how it selects the appropriate IP address if there are multiple IP addresses associated with a domain, for support of multi-region optimization.

permalinks – Migrate wordpress from nginx to static

I currently have a wordpress site using simple links for each message (that is, /? P = 123) above nginx. I want to migrate this site to a static site only, but I do not want to ruin the links of other blogs to mine and the results of search engines on the blog as well.

There are some plugins that will convert my site to static, but they all require non-simple permalinks when I have them. Plus, just about every instruction I can find is about 302 redirects with apache2. I'm running nginx.

Is there a way to do this? I guess it would be done in stages. First, I have to change permalinks to make it work. Then I have to run 302, then? P = 123 is redirected to the correct permalink. Finally, convert everything to static.

8 – How can I replace file and static media links in the content with their equivalent entity references?

I have imported content from another system. So, for example, the body has a typical HTML code, like this:

Is there a way to retrospectively retrieve and replace all static link references with their Drupal 8 feature reference equivalents, perhaps by searching for the unique file name? Or is there a way to achieve this during the initial import / reimportation?

I also need to do it for internal links.

Web Hosting – How to point a subdirectory URL of a static website to a Heroku application?

I have a static website, hosted on BlueHost and a React / Express application hosted on Heroku. I was wondering if it was possible to do something like this.

Access the static site with:

Access the Heroku app with:

What parameters should I look for when setting up this structure? Thank you!