Understanding the 'static' Keyword in Vue.js Component

In Vue.js, the 'static' keyword is used to prevent reactivity on a property. This means that a static property won't cause a component to re-render when it changes. In practical terms, this can be particularly useful for performance optimization when dealing with larger or more complex Vue.js applications.

In order to help you understand the 'static' keyword better, let's consider a simple example. You have a Vue.js component where a certain property gets updated frequently. However, this property's update does not affect the component's view in any way and thus, it doesn't need to cause a render. In such cases, you can use the 'static' keyword to declare this property static and stop Vue.js from tracking its changes to prevent unnecessary re-renders.

Here is a Vue.js code snippet demonstrating the above scenario:

<template>
  <div>
    <p>Counter: {{ counter }}</p>
  </div>
</template>
<script>
export default {
  data() {
    return {
      // Using 'static' keyword to prevent Vue.js from tracking changes on the property 'nonReactiveProp'
      static: {
        nonReactiveProp: 'Value does not affect the component view',
      },
      counter: 0,
    }
  },
  methods: {
    incrementCounter() {
      this.counter++
      this.static.nonReactiveProp = 'New value that does not require a render'
    },
  },
}
</script>

In this example, nonReactiveProp is declared as a static property. So, even when it gets updated in incrementCounter method, it won't trigger a re-render of the component, thus optimizing the performance.

Note that 'static' doesn't make a variable globally accessible across different components (for that, you might want to look into Vue's global properties or Vuex). Nor does it prevent a property from being included in the template, since non-reactive properties can certainly be used in templates – they just won't cause a re-render if they change.

In conclusion, understanding and effectively manipulating reactivity can make a significant difference in your Vue.js applications. By preventing reactivity on properties that do not affect the view, you can optimize your app's performance and enhance the user experience.