How to refresh parameterized sliderInput based on value params

[Felipe]

I am doing monthly reports and would like to dynamically refresh the slider based on the year that I select from the drop down. My dataset ranges from years 2005 to 2015 and the slider is currently showing 2012 data. Two-fold question,How can I refresh the sliderInput to 2010 and how do I limit the Year dropdown control to only show the years on my dataset (2005 to 2015)? Below is the yaml and screenshot is attached.

title: "Salmon Program"
date: "`r format(Sys.Date())`"
output:
  pdf_document:
    toc: yes
    toc_depth: '4'
  html_document:
    toc: yes
    toc_depth: '4'
    keep_md: yes
params:
  glimpse: no
  Runs:
    label: Salmon Runs
    value:
    - Winter
    - Spring
    - Fall
    - LateFall
    input: select
    choices:
    - Winter
    - Spring
    - Fall
    - LateFall
    multiple: yes
  Year: 2012  
  Dates:
    input: slider
    min: !r as.Date("2012-01-01") #Can this be dynamically changed based on the report dates?
    max: !r as.Date("2012-12-31")
    value: !r c(as.Date("2012-01-01"), as.Date("2012-01-30")) 
    step: 30