Is it possible to access Twig variables in a plugin variable using PHP?

Question

I have a controller that returns route variables to the page:

craft()->urlManager->setRouteVariables(array(
  'errors' => $entry->getErrors()
));

On the page that gets loaded, I can access the variables I set in the template:

{% for error in errors %} ...

However, I want to handle this variable dynamically. Is it possible to access the 'errors' variable in my MyPluginVariable.php file without passing it directly to my variable function?

I don't want to do this:

{{ craft.myPlugin.doSomething(errors) }}

That passes my variable to the plugin variable and I can access it just fine. But I don't want to ask the user to pass this variable to the function every time, I'd prefer to just handle it in the background.

So, on the page that gets loaded, instead of outputting the variable, can I have a Twig tag like this:

{{ craft.myPlugin.doSomething() }}

And directly access the 'errors' variable in my plugin? Something like (this doesn't work):

craft()->request->getRouteVariables('errors')

Answer 1

You can’t access the current Twig variables (the “context”, as Twig calls them), from a Template Variable class, but you can access them with a template hook.

From your plugin’s init() function:

craft()->templates->hook('errorCheck', function(&$context)
{
    if (isset($context['errors']))
    {
        // do something with $context['errors'];
    }
});

From your template:

{% hook "errorCheck" %}

You can modify, delete, and create variables within that $context array if you want. And because it is passed by reference (that’s what the “&” does in “&$context”, you won’t need to actually return the array at the end of the function or anything; just make your changes to it.

Answer 2

I ended up solving this by creating a public variable in my service layer and assigning and retrieving the submitted object from there. This helps me keep any new error handling specific code out of the templates for the users, and the output tag can now handle both submitting and error handling in the form.

This method has three parts:

1. Public variable in the service layer that handles the submitted Form object (this gets set after the submission is validated and gets retrieved, if it exists, when the tag is processed.
2. Controller that handles the Form submission
3. Variable in the template file
   craft.sproutForms.outputForm()

More specifically, our service layer has a public variable:

public $activeEntry;

If our submission fails, we assign the submitted object with errors to the $activeEntry variable:

if (craft()->myPlugin->saveEntry($entry)) 
{
   ...
}
else
{
   craft()->myPlugin->activeEntry = $entry;

   ...
}

And, when the page loads and the outputForm() tag is processed, we check to see if that $activeEntry variable is set.

if (isset(craft()->myPlugin->activeEntry))
{
    $entry = craft()->myPlugin->activeEntry;    
}
else
{
    $entry = new MyPlugin_EntryModel();
}