{"id":47023,"date":"2017-03-15T11:13:44","date_gmt":"2017-03-15T05:43:44","guid":{"rendered":"http:\/\/www.tothenew.com\/blog\/?p=47023"},"modified":"2017-03-15T11:13:44","modified_gmt":"2017-03-15T05:43:44","slug":"how-to-programmatically-replace-the-content-in-the-custom-block-in-drupal-8","status":"publish","type":"post","link":"https:\/\/www.tothenew.com\/blog\/how-to-programmatically-replace-the-content-in-the-custom-block-in-drupal-8\/","title":{"rendered":"How to Programmatically Replace the Content in the Custom Block in Drupal 8?"},"content":{"rendered":"

Replacing the content in the custom block is often challenging.\u00a0In Drupal 8<\/a>, the best way to replace the content in the custom block programmatically is to use module_preprocess_block alter.<\/p>\n

We have created a custom block and now we want to replace the value of the placeholder programmatically. For eg. On http:\/\/example.com\/, we have created a custom block named “Test Block” for the home page. The body of the\u00a0custom block contains the following code:<\/p>\n

[java]<\/p>\n

<div>
\n<div class="\u201ccontent\u201d">
\n<h5><a href="\u201c{{link}}\u201d">Test Block<\/a><\/h5> \/\/ {{link}} represents the placeholder
\n<\/div>
\n<\/div><\/p>\n

[\/java]<\/p>\n

Now we want to replace the value of placeholder ({{link}}) with a node page URL link programmatically. Here’s how to go about it:<\/p>\n

Create an alter module by following the below steps:<\/p>\n

Step 1- Create a test folder in the modules folder
\nStep 2- Create “test.info.yml” file that will have entire information about module such as name, type, package, version.<\/p>\n

[java]
\nname: Test Block
\ndescription: ‘Module to replace the placeholder.’
\npackage: Custom
\ntype: module
\ncore: 8.x
\n[\/java]<\/p>\n

Step 3- Create “test.routing.yml” file and add routing for this module
\nStep 4- Create “test.module” file which will contain the preprocess alter of the custom block. The custom block contains the placeholder
\nStep 5- Open the test.module file and add preprocess alter code as shown below:<\/p>\n

[java]
\n use Drupal\\Core\\Block\\BlockBase;
\n use Drupal\\node\\Entity\\Node;
\n use Drupal\\Core\\Url;
\n use Drupal\\file\\Entity\\File;
\n use Drupal\\field\\Entity\\FieldConfig;<\/p>\n

\/**
\n * function preprocess block for Test block
\n *\/
\n function test_preprocess_block(&$variables)
\n {<\/p>\n

if (isset($variables[‘content’][‘#block_content’]))<\/p>\n

{
\n $content = $variables[‘content’][‘#block_content’];
\n if( method_exists($content,’id’) && $content->id() == ‘block_id’)
\n\/*
\n* Block Id represents id of coressponding block which contains the placeholder.
\n*\/
\n {
\n $body = $variables[‘content’][‘body’][0][‘#text’];
\n \/*
\n * now you need to replace with placeholder by finding the dynamic link
\n *\/
\n $query = \\Drupal::entityQuery(‘node’);
\n $query->range(0, 1);
\n $result = $query->execute();
\n $nids = array_values($result);
\n if (isset($nids[0]))
\n {
\n $node_load = Node::load($nids[0]);
\n $options = array(‘absolute’=>TRUE);
\n $url = Url::fromRoute(‘entity.node.canonical’, [ ‘node’=>$nids[0] ], $options);
\n $Url = $url->toString();
\n $body=str_replace(‘{{link}}’,$Url,$body);
\n $variables[‘content’][‘body’][0][‘#text’] = $body;
\n }
\n }
\n }
\n }
\n[\/java]<\/p>\n

The Block Id and the placeholder are highlighted in the following image:<\/p>\n

\"screenshot(3)\"<\/p>\n

We hope you will able to now replace the content in your custom block easily following the above steps. In case if you have more queries about Drupal 8 custom blocks, feel free to share them in the comments below.<\/p>\n","protected":false},"excerpt":{"rendered":"

Replacing the content in the custom block is often challenging.\u00a0In Drupal 8, the best way to replace the content in the custom block programmatically is to use module_preprocess_block alter. We have created a custom block and now we want to replace the value of the placeholder programmatically. For eg. On http:\/\/example.com\/, we have created a […]<\/p>\n","protected":false},"author":1077,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":148},"categories":[3602,1],"tags":[4496,4490,3601,4495,4489],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/47023"}],"collection":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/users\/1077"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/comments?post=47023"}],"version-history":[{"count":0,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/47023\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/media?parent=47023"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/categories?post=47023"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/tags?post=47023"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}