Building blocks in AEM

Building blocks is the feature associated with experience fragment in which we group two or more experience fragment together.

To understand it better we have to first understand the experience fragment. Experience fragment is a page or post, which we create using multiple small contents or grouping multiple content together in a template so we can easily reuse and publish that content. Experience fragment can have CTA(cal to action), images, text and inputs.

Why building blocks required?

Suppose we have a requirement where we need to show two or more experience fragment together as a single experience fragment, then using the building blocks we can group those experience fragment and  drop and show that building blocks as a single experience fragment in your post and page.

To make it more simple, building blocks is for combining two or more experience fragment into a single experience fragment.

How to create building blocks?

Failure authenticating with BASIC 'Sling (Development)'

Issue: When we try to replicate anything from author to publisher I am getting below error. and not even on any replication it keep printing the log in error.log file automatically after an interval. What could be the cause of this? 

24.10.2019 11:31:05.942 *INFO* [oak-repository-executor-1] com.adobe.granite.repository Service [34344, [org.apache.jackrabbit.oak.api.jmx.SessionMBean]] ServiceEvent REGISTERED
24.10.2019 11:31:20.180 *INFO* [sling-default-2812-com.day.cq.replication.impl.ReverseReplicator.22529] org.apache.commons.httpclient.auth.AuthChallengeProcessor basic authentication scheme selected
24.10.2019 11:31:20.180 *INFO* [sling-default-2812-com.day.cq.replication.impl.ReverseReplicator.22529] org.apache.commons.httpclient.HttpMethodDirector Failure authenticating with BASIC 'Sling (Development)'@localhost:4503
24.10.2019 11:31:24.323 *INFO* [oak-repository-executor-1] com.adobe.granite.repository Service [34345, [org.apache.jackrabbit.oak.api.jmx.SessionMBean]] ServiceEvent REGISTERED

Resolution: This error message you are getting because, AEM author replication agent is unable to communicate with publisher instance due to bad credential (username and password). You might change the password of admin user in publisher and forget to update the password on default author agent. Once you will update the valid authentication credential in default author replication agent this error will be no more logged in the error.log file.

By default AEM system keep generating events and try to transport the same to publisher instance, every time it send the replication request to replication agent the authentication get failed thats why this log is get printed after a certain interval. 

Reference:

https://helpx.adobe.com/in/experience-manager/6-3/sites/deploying/using/replication.html

How to put escape character in SQL query

SELECT * FROM SQL_TUTORIAL WHERE SQL_NAME like UPPER('%'||vSearchItem||'%')