Filter list with Vue.js

I just got started with Vue.js and here is what I'm doing: I am rendering a list of products, and each product has a name, a gender and a size. I'd like users to be able to filter products by gender, by using an input to type the gender.

var vm = new Vue({
      el: '#product_index',
      data: {
        gender: "",
        products: [{name: "jean1", gender: "women", size: "S"}, {name: "jean2", gender: "men", size: "S"}]
      },
      methods:{
        updateGender: function(event){
          this.gender = $(event.target).val()
        }
      }
    }
  )

  <div v-for="product in products" v-if="...">
    <p>{{product.name}}<p>
  </div>
  <input v-on:change="updateGender">

I managed to get the gender updated, but I have an issue with the filtering part. When the page loads, I don't want any filtering. In the documentation, they advise to use v-if but it doesn't seem compatible with this configuration.

If I use v-if, I could do:

v-if="product.gender == gender" 

But again, this doesn't work when the page load because gender is empty. I couldn't find a workaround for this.

How should I approach this issue ?

Use computed properties - something like this (Example bellow filter items by type)

const app = new Vue({
  
  el: '#app',
  
  data: {
     search: '',
     items: [
       {name: 'Stackoverflow', type: 'development'},
       {name: 'Game of Thrones', type: 'serie'},
       {name: 'Jon Snow', type: 'actor'}
     ]
  },
  
  computed: {
    filteredItems() {
      return this.items.filter(item => {
         return item.type.toLowerCase().indexOf(this.search.toLowerCase()) > -1
      })
    }
  }
  
})

Template:

  <div id="app">
    
    <div v-for="item in filteredItems" >
      <p>{{item.name}}</p>
    </div>
    
    <input type="text" v-model="search">
    
  </div>

Demo: http://jsbin.com/dezokiwowu/edit?html,js,console,output

You can try v-if="!gender || product.gender == gender"

Just modified @Nora's answer.

You need to change in the template as:

 <div id="product_index">
    <div v-for="product in products" v-if="!gender || product.gender===gender">
      <p>{{product.name}}<p>
    </div>
    <input v-on:change="updateGender">
  </div>

and in JS file as:

var vm = new Vue({
      el: '#product_index',
      data: {
        gender: "",
        products: [{name: "jean1", gender: "women", size: "S"}, {name: "jean2", gender: "men", size: "S"}]
      },
      methods:{
        updateGender: function(event){
          this.gender = event.target.value
        }
      }
    }
  );

Working Demo: https://jsbin.com/qocuraquki/edit?html,js,console,output

computed: {
        filteredItems() {
          return this.allStartupData.filter(item => {
            let byName =
              item.name.toLowerCase().indexOf(this.search.toLowerCase()) > -1;
            let byDescription =
              item.description.toLowerCase().indexOf(this.search.toLowerCase()) >
              -1;
            if (byName === true) {
              return byName;
            } else if (byDescription === true) {
              return byDescription;
            }
          });
        }
      }

and then u can iterate through filteredItems like e.g

 <v-flex v-for="(obj,index) in filteredItems" :key="index" xs12 md4>