title: Using EmbeddedValueResolver with @Conditional
body: <p>Problem context: in our application we use custom <code>PropertySourcesPlaceholderConfigurer</code> to extend possibilities of <code>EmbeddedValueResolver</code> with custom property sources. I am very inspired of Spring Boot <code>@ConditionalOnProperty</code> and <code>@ConditionalOnExpression</code> and want to use it with custom placeholders.</p>
  
  <p>What I wanted to do was to write custom <code>@Conditional</code> annotation that uses <code>EmbeddedValueResolver</code> to resolve placeholders (<code>${...}</code>). I noticed that <code>ConfigurationClassPostProcessor</code> implements <code>ResourceLoaderAware</code> interface, and <code>ResourceLoaderAware</code> classes are configured later than <code>EmbeddedValueResolverAware</code> ones. So when we initialize <code>ResourceLoaderAware</code>, our <code>EmbeddedValueResolverAware</code> beans are already configured. So potentially solution seems possible. </p>
  
  <p>What I wanted to do next was to write custom <code>Condition</code> that uses <code>EmbeddedValueResolver</code> from <code>ApplicationContext</code> to resolve some property and match it to some value. But the problem is that <code>Condition</code> uses some another context class called <code>ConditionContext</code> which doesn't include <code>EmbeddedValueResolver</code>. Using <code>Environment#resolvePlaceholder</code> doesn't help - seems like <code>Environment</code> doesn't know anything about placeholders that are available through <code>EmbeddedValueResolver</code>.  </p>
  
  <p>So, is that possible to use <code>EmbeddedValueResolver</code> with Spring conditionals? </p>