== Why is this an issue?

DML statements should not be executed in class constructors, https://developer.salesforce.com/docs/atlas.en-us.apexcode.meta/apexcode/apex_classes_static.htm[instance initialization code blocks or static initialization code blocks] for two reasons:

* It is counter intuitive. Developers will not expect the instantiation of an object to modify records.
* Constructor and/or initialization code blocks of VisualForce controllers will fail if they try to execute DML statements. This is also true for indirect calls to DML statements: they can't instantiate objects which execute DML statements in their own constructors/initialization code. Having to check if a constructor can or cannot be called makes development more complex.

This rule raises an issue when a class constructor, an instance initialization block or a static initialization block executes a DML statement.


=== Noncompliant code example

[source,apex]
----
public class MyController {
    {
        List<Task> tasks = [Select Id, Subject FROM Task];
        for (Task t : tasks) {
            t.subject = 'instance initialization code block';
        }
        update tasks;  // Noncompliant
    }

    static {
        List<Task> tasks = [Select Id, Subject FROM Task];
        for (Task t : tasks) {
            t.subject = 'static initialization code block';
        }
        update tasks;  // Noncompliant
    }

    public MyController() {
        List<Task> tasks = [Select Id, Subject FROM Task];
        for (Task t : tasks) {
            t.subject = 'constructor';
        }
        update tasks;  // Noncompliant
    }
}
----


=== Compliant solution

[source,apex]
----
public class MyController {
    public MyController() {
    }

    // For example, move the DML statement to a method called when a user clicks a button
    public updateTasks() {
        List<Task> tasks = [Select Id, Subject FROM Task];
        for (Task t : tasks) {
            t.subject = 'test';
        }
        update tasks;
    }
}
----

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

=== Message

* Move this DML statement out of the constructor.
* Move this DML statement out of this initialization code block.


=== Highlighting

each DML statement


endif::env-github,rspecator-view[]