IncompatibleService.qhelp

<!DOCTYPE qhelp PUBLIC
"-//Semmle//qhelp//EN"
"qhelp.dtd">
<qhelp>

  <overview>
    <p>
      AngularJS has built-in support for dependency injection:
      components can simply list the names of the services they depend
      on, and AngularJS will provide appropriate instances and pass
      them as arguments at runtime.
    </p>

    <p>
      Each injected service has a kind, this kind influences which
      components the service is compatible with.
    </p>
  </overview>

  <recommendation>
    <p>
      Ensure that declared dependencies have the right kind for the
      component they are injected into.
    </p>
  </recommendation>

  <example>
    <p>
      The following example shows a <code>config</code>-method that
      lists a dependency on a service named <code>year</code>.

      Later, a service of kind <code>value</code> is defined with the
      name <code>year</code>.

      This is not allowed, since <code>config</code>-methods can only
      be injected with services of kind <code>provider</code> or
      <code>constant</code>.
    </p>

    <sample src="examples/IncompatibleService.js"/>

    <p>
      To solve this problem, the <code>year</code> service has to be
      of kind <code>constant</code>.
    </p>

    <sample src="examples/IncompatibleService-fixed.js"/>
  </example>

  <references>
    <li>AngularJS Developer Guide: <a href="https://docs.angularjs.org/guide/di">Dependency Injection</a>.</li>
  </references>
</qhelp>