uniqueEntity message - symfony

Question

i've created a form with symfony 2, and i check if the fields are unique with the UniqueEntity constraint. But i want the fields "firstname", "name" to appear in the message, like:
"Mark Blaze already exists!" rather than "this person already exists!"
can someone help?
part of the form builder
public function buildForm(FormBuilderInterface $builder, array $options) {
$builder
->add('firstname')
->add('name')
Entity
/**
* #ORM\Entity
* #ORM\Entity(repositoryClass="InviteRepository")
* #UniqueEntity(fields={"firstname","name"}, message="this person already exists!")
*/
class Invite {
/**
* #ORM\Column(type="string",length=50)
*/
private $firstname;
/**
* #ORM\Column(type="string",length=50)
*/
private $name;
twig file
{{ form_start(form) }}
{{ form_errors(form) }}
{% spaceless %}
<div class="control-group">
{{ form_label(form.firstname, 'firstname *', { 'label_attr': { 'class':'control-label'} }) }}
{{ form_errors(form.firstname) }}
<div class="controls">
{{ form_widget(form.firstname) }}
{% if form.vars.help is defined %}
<span class="help-block">{{ form.vars.help }}</span>
{% endif %}
</div>
</div>
{% endspaceless %}
{% spaceless %}
<div class="control-group">
{{ form_label(form.name, 'name *', { 'label_attr': { 'class':'control-label'} }) }}
{{ form_errors(form.name) }}
<div class="controls">
{{ form_widget(form.name) }}
{% if form.vars.help is defined %}
<span class="help-block">{{ form.vars.help }}</span>
{% endif %}
</div>
</div>
{% endspaceless %}
Much thanks

Answer 1

In theory you can use this in the error message {{ value }} and this will represent the sent value. I use this in the emailconstraint so, 'The {{ value }} email address already in use'.
I think this would work for you too.
I rechecked your constraint and sadly, there you don't have the option to set a dynamic value. What I posted earlier was a solution for a really symfony validation and this constraint is part of doctrine. But any time, you can create your own constraint, if you want to fulfil your special needs:
$this->context->addViolationAt($errorPath, $constraint->message, array(), $criteria[$fields[0]]);