route is redirecting to wrong path - ruby-on-rails

Question

This is what my routes currently look like:
which gives
On my homepage I have a create vacancy button
<%= link_to "plaats", new_employer_vacancy_path(:employer_id)%>
Which should be linked to the line from the first image
get '/employers/:employer_id/vacancies/new', to: 'vacancies#new', as: 'new_employer_vacancy'
In the vacancies_controller#new - create I have:
def new
#vacancy = Vacancy.new
#employervacancy = Employervacancy.new
end
def create
#vacancy = Vacancy.create(vacancy_params)
createEmployervacancy
redirect_to employer_vacancy_path(current_employer, #vacancy)
end
def createEmployervacancy
#employer = current_employer
Employervacancy.create(vacancy_id: #vacancy.id, employer_id: #employer.id)
end
But whenever I click the button I get redirected to some other method in my vacancies_controller that is totally irrelevant.
How is this even possible? Don't I clearly define that when that path is clicked he should go to vacancies#new? and not to vacancies#show_specific_employer_vacancies?
EDIT
After following the answers I am indeed being linked to the correct route.
First, it gave me this error.
After trying to pass the current_employer.id instead of #employer like suggested I got following error:

Answer 1

For your routes, you'd better to change into nested route for easily maintaining routes.
Remove these codes:
get '/employers/:employer_id/vacancies/:id', to:"vacancies#show_specific_employer_vacancies", as: "employer_vacancy"
get '/employers/:employer_id/vacancies/edit/:id' ...
get '/employers/:employer_id/vacancies/index' ...
get '/employers/:employer_id/vacancies/new' ...
path '/employers/:employer_id/vacancies/:id' ...
change into:
resources :employers do
resources :vacancies
end
Try to use basic routes here because you use standard simple form url. For example:
<%= simple_form_for(#employee, #vacancy) %>
The simple_form_for will generate url well if you use nested routes above.
Finally, in your link you have to add #employer_id
<%= link_to "plaats", new_employer_vacancy_path(:employer_id => #employer_id)%>
I hope this help you

Answer 2

Your router cannot tell the difference between your employer_vacancy and new_emplyer_vacancy routes because the :id parameter accepts anything. Because of this, when you point your browser to "/employers/5/vacancies/new", the route is taking your employer_vacancy route and assigning {:employer_id => 5, :id => "new"} instead of going to your new_employer_vacancy route (because routes are first-come-first-serve).
To correct this, add a constraint to your first route to ensure that only numbers (and not the string "new") is accepted into the employer_vacancy route:
get '/employers/:employer_id/vacancies/:id',
to: 'vacancies#show_specific_emplyer_vacancies',
as: 'employer_vacancy',
constraints: { id: /\d+/ } # <- This line

Answer 3

As Wes Foster said rails router is trying to find a first match.
It means that given a path /employers/999/vacancies/new your router looks through the routes and when it sees get '/employers/:employer_id/vacancies/:id he thinks that this route matches. So :employer_id is 999 and :id is new.
I'd suggest to put the route with :id at the end of employers routes:
...
get '/employers/:employer_id/vacancies/new'
...
get '/employers/:employer_id/vacancies/:id'
Btw this is better than adding a constraint because:
It is easier
It doesn't pollute routes file
Later you may want to change ids to be hashed or alphabetic and then you'd have to change the constraint