How to alter or add custom url links in simple sitemap in drupal 8?

 It is very simple method, we have 2 options in Drupal 8.

https://www.drupal.org/project/simple_sitemap

1. we can add by config page of module like (//localhost//admin/config/search/simplesitemap/custom). There add custom links with priority with change frequency.

2. we can use alter method with simple steps::

a. Create any custom module or write code in any existing custom module.

b. go to custom_module.module file or create new if not exist.

c. write code line with below given example:

Example:

First render class library in file header.

use Drupal\simple_sitemap\Simplesitemap;

/**

 * Use this hook to add arbitrary links to the sitemap.

 *

 * @param array &$arbitrary_links

 */

function finder_simple_sitemap_arbitrary_links_alter(&$arbitrary_links) {

  // Add an arbitrary link.

  $arbitrary_links = array([

    'url' => 'https://localhost/applications',

    'priority' => '0.9',

    'lastmod' => '2020-05-25T14:40:30+02:00',

    'changefreq' => 'daily',

],

[

'url' => 'https://localhost/products',

    'priority' => '0.7',

    'lastmod' => '2020-07-15T13:40:30+02:00',

    'changefreq' => 'daily',

    ],

);

}

Note: We can't add date(lastmod) in custom links by admin, so we have to use alter code for add dates(lastmod) in custom create links.

Note: If have any suggestions or issue regarding 'How to alter or add custom url links in simple sitemap in drupal 8?' then you can ask by comments. 

How to remove HTTP headers from drupal 8?

Sometimes client requirement is to remove HTTP headers from the website. By default, in Drupal website X-Generator, X-Drupal-Dynamic-Cache and X-Drupal-Cache HTTP headers is HTTP headers.

If we want to hide to remove from view source of page.

We can use Drupal module "Remove HTTP headers"

link: https://www.drupal.org/project/remove_http_headers

That will remove easily… 

headers_to_remove:

  - 'X-Generator' 

  - 'X-Drupal-Dynamic-Cache'

  - 'X-Drupal-Cache'

  

Important Note: if you get any issue/error, you can use this patch.

1. Go to your module and find folder route file - src/EventSubscriber/RemoveResponseHeadersSubscriber.php

2. find this function -

class RemoveResponseHeadersSubscriber implements EventSubscriberInterface {

    

   public function removeResponseHeadersItem(FilterResponseEvent $event) {

     $response = $event->getResponse();

+    $config = $this->configFactory->get('remove_meta_and_headers.settings');

 

     // If TRUE, fire event to remove X-Generator from Response.

-    if (1 == $this->configFactory->get('response_header_x_generator')) {

+    if ($config->get('response_header_x_generator')) {

       $response->headers->remove('X-Generator');

     }

   }

OR check this patch link…

https://www.drupal.org/files/issues/2019-09-03/php_notices_fix_3078971-1.patch

   

Note: If have any suggestions or issue regarding 'How to remove HTTP headers from drupal 8?' then you can ask by comments. 

How to protect file from public access in Drupal 8?

If we don't want to show any file or folder to 'Anonymous user', 'Authenticated user' then we have 2 options.

1. We can set the 'Permission' for this file or folder.

2. If we are using Pantheon server then we have 'pantheon.yml' file on root.

Write the code there.

protected_web_paths:

  - /web.config

  - /core/package.json

And this way easily we can protect our file or folder from unknown users.

Note: If have any suggestions or issue regarding 'How to protect file from public access in Drupal 8?' then you can ask by comments. 

How to set the flood limit in Drupal 8?

Sometimes, we get the flood of Unlimited attempts of login fail message, block user, block IP. In that case our website handle unwanted extra data, extra burden on database that is not good for our website health.

So what we have to do, in Drupal 7, we have module that name is "Flood control" https://www.drupal.org/project/flood_control

But in Drupal 8 we don't have that module, So many times we get the error message that is very famous: "Login blocked after 5 failed login attempts".

In that case or if we want to overcome this problem Drupal 8 we have solution, we are going to share:

Code for Flood limit change:

$flood_limit = 5;                 //Default value is 5, change whatever you want. 

// for login form

\Drupal::configFactory()->getEditable('login.settings')

      ->set('flood.limit', $flood_limit)

      ->save();

// for contact form

$flood_limit = 5;                //Default value is 5, change whatever you want. 

\Drupal::configFactory()->getEditable('contact.settings')

      ->set('flood.limit', $flood_limit)

      ->save();   

  

Code for Flood interval change:

// for login form

$flood_interval = 3600;      //Default value is 3600sec (1hour), change whatever you want

 \Drupal::configFactory()->getEditable('login.settings')

      ->set('flood.interval', $flood_interval)

      ->save();

// for contact form

$flood_interval = 3600;     //Default value is 3600sec (1hour), change whatever you want

 \Drupal::configFactory()->getEditable('contact.settings')

      ->set('flood.interval', $flood_interval)

      ->save();   

  

Important Notice: Put this code in custom module or template or theme file.

Or we can use 'settings.php' option for this code

$flood_limit = 10;

$config['login.settings']['flood']['limit'] = $flood_limit; 

And another we have a module in drupal 8, we can use this and all this code feature is there. Please find this "Flood settings" module. https://www.drupal.org/project/flood_settings 

Note: If have any suggestions or issue regarding 'How to set the flood limit in Drupal 8?' then you can ask by comments.  

How to check log error messages in Drupal 8?

As we know about log messages in Drupal, Log messages are our project related, every user related track (error, notice, warning, failure, PHP issue). In our Drupal we can check that track with URL '/admin/reports/dblog'.

And if we create a custom Module and we want to track every event of module, every time activity that we can write that code in this module.

Logs with an arbitrary level:

\Drupal::logger('module_name')->log($message); //When a module was installed

Normal but significant events:

\Drupal::logger('module_name')->notice($message); //Normals events, as cron execution

Exceptional occurrences:

\Drupal::logger('module_name')->warning($message); //exceptional cases not an error

Errors:

\Drupal::logger('module_name')->error($message); //error messages

And If we have requirement that we want to track this log error message by File, 

In that case we have a Drupal 8 module that we can install "File Log" module.

After configure, that file will be Create in root area Bydefault "site/default/files/logs".

I am going to share that module link here.

https://www.drupal.org/project/filelog

Note: If have any suggestions or issue regarding 'How to check log error messages in Drupal 8?' then you can ask by comments.  

Difference between hook_entity_presave and hook_entity_insert ?

Simple way to differentiate both hooks is the 'ID' is not available in hook_entity_presave() ("pre meaning before, and without saved ID is not assigned in database),
But this 'ID' will be available in hook_entity_insert().

Example:
function mymodule_node_insert(NodeInterface $node) { 
  $nid = $node->id();
}
OR
function mymodule_node_insert($node) {
  if ($node->getType() == 'your content type') {
        $node->setTitle('New entity ' . $node->id()); // to update title with node id
        $node->field_test = 'Id' . $node->id();  // or, to update a text field with node id
        $node->save();
  }
}

function mymodule_entity_presave(Drupal\Core\Entity\EntityInterface $entity) {
  if ($entity->getEntityType()->id() == 'node') {
    $entity->setTitle('New Title here');
    //Note : Not to save, because it's automatic.   
  }
}
OR
function mymodule_node_presave(Drupal\node\NodeInterface $node) {
  $node->setTitle('Edited Title');
  $node->set('body', 'this is the new body section');
  //Note : Not to save, because it's automatic.
}

Note: If have any suggestions or issue regarding 'Difference between hook_entity_presave and hook_entity_insert ?' then you can ask by comments.  

How to use breakpoints in drupal 8?

There we have simple way to use breakpoints means separate media query in drupal 8 and that will also help in speed up or optimize the website.
We have some following points, that will easily clear your doubts about breakpoints and separate media query.
1. We will create a file with the name of 'yourthemeORmoduleName.breakpoints.yml', Example for theme like your theme name is 'bartik' the file name will be 'bartik.breakpoints.yml'.
2. This breakpoints file will be use for write the code of media query for responsiveness. This file will be located in 'themes/bartik/' root.
Example:
bartik.mobile:
  label: mobile
  mediaQuery: ''
  weight: 0
  multipliers:
    - 1x
    - 1.5x
    - 2x    
bartik.narrow:
  label: narrow
  mediaQuery: 'all and (min-width: 560px) and (max-width: 850px)'
  weight: 1
  multipliers:
    - 1x
    - 1.5x
    - 2x    
bartik.wide:
  label: wide
  mediaQuery: 'all and (min-width: 851px)'
  weight: 2
  multipliers:
    - 1x
    - 1.5x
    - 2x    
bartik.small:
  label: small
  mediaQuery: "(min-width: 0px)"
  weight: 1
  multipliers:
    - 1x
    - 1.5x
    - 2x
bartik.medium:
  label: medium
  mediaQuery: "(min-width: 768px)"
  weight: 2
  multipliers:
    - 1x
    - 1.5x
    - 2x
bartik.large:
  label: large
  mediaQuery: "(min-width: 1024px)"
  weight: 3
  multipliers:
    - 1x
    - 1.5x
    - 2x
Here the breakpoint properties are:
    Very first we will take a unique breakpoint name like: bartik.small:      (moduleName/themeName.unique breakpointName),
    Example: bartik.small: ,bartik.medium: ,bartik.large: ,bartik.wide: ,bartik.narrow: ,bartik.mobile:
   
    label - The human readable name of the breakpoint
    mediaQuery - a valid @media query(for responsiveness)
    weight - where the breakpoint is ordered in relation to other breakpoints
    multiplier - the ratio between the physical pixel size of the active device and the device-independent pixel size
               - 1x
               - 1.5x // supports Android
               - 2x  // supports Mac retina display
              
3. After that we will create new library and attach this breakpoints in 'bartik.libraries.yml' file.
Syntax:
libraryName:
  version: 1.0
  css:
    theme:
      css/desktop-small.css: { media: all and (min-width: 851px) }
      css/mobile.css: { media: only screen and (max-width: 767px) }
      css/mobile-common.css: { media: all and (min-width: 560px) and (max-width: 850px) }
     
    Same like we can create many viewports / breakpoints / media queries and attach with libraries and templates of our website.

4. Now this specific library we will render on template where we want to apply.
Example: {{ attach_library('mythemeName/libraryName') }}   

So in this way we can optimize the site and increase the performance with the help of breakpoints because with the help of this only in case of Mobile or Tab or Ipad or Desktop specific mentioned css will be rendered else not.
And the most important thing is clear the Cache and run Cron.

Note: If have any suggestions or issue regarding 'How to use breakpoints in drupal 8?' then you can ask by comments.