VueJs - bind input to url param

The most straight-forward way I found was the following:

<input v-model="foo" />

--

data() {
    return {
        foo: this.$route.query.foo
    };
},
watch: {
    foo(newVal) {
        this.$router.push({ query: { ...this.$route.query, foo: newVal } });
    },
    '$route.query.foo': function(val) {
        this.foo = val;
    }
}

Edit 2019-08-16: added watch for $route to react to back navigation.

A bit of time has passed, but since the docs say "it is often a better idea to use a computed property rather than an imperative watch callback" I thought I would add this pattern which I tested successfully and also looks more elegant IMHO.

The idea is to use a computed property linked to the query param with explicit get and set methods and bind the input with v-model to that property.

So in your template:

<input v-model="query_param"/>

Then in your computed properties:

computed: {
  query_param: {
      get() {
        return this.$route.query.your_query_param
      },
      set(value) {
        /*  Here I use replace so that you're not actually 
        pushing a new page to the history stack */

        this.$router.replace({  
          query: {
            ...this.$route.query,
            your_query_param: value
          }
        })
      }
    }
}

This of course would work for a single query parameter. If you have multiple inputs you want to bind to different parameters just put additional computed properties in the same way.

Yes, it is possible. In my code, I have a <select> element on change of which I want to append the selected value to url as query. So, I have done like this:
My previous URL was:

localhost:8080/books

<select class="form-control" v-on:change="appendQueryToUrl" v-model="filterData.genre">

methods: {
      appendQueryToUrl() {
          this.$router.push({query: {genre: this.filterData.genre}})
      }
}

Where genre is my key and this.filterData.genre is my local object value. Now my url looks like:

localhost:8080/books/?genre=Computer

Thanks and inform me if any error.