Built-in Special Elements #

<component> #

A "meta component" for rendering dynamic components or elements.

• Props

  interface DynamicComponentProps {
    is: string | Component
  }
  

• Details

  The actual component to render is determined by the is prop.

  • When is is a string, it could be either an HTML tag name or a component's registered name.

  • Alternatively, is can also be directly bound to the definition of a component.

• Example

  Rendering components by registered name (Options API):

  <script>
  import Foo from './Foo.kdu'
  import Bar from './Bar.kdu'
  
  export default {
    components: { Foo, Bar },
    data() {
      return {
        view: 'Foo'
      }
    }
  }
  </script>
  
  <template>
    <component :is="view" />
  </template>
  

  Rendering components by definition (Composition API with <script setup>):

  <script setup>
  import Foo from './Foo.kdu'
  import Bar from './Bar.kdu'
  </script>
  
  <template>
    <component :is="Math.random() > 0.5 ? Foo : Bar" />
  </template>
  

  Rendering HTML elements:

  <component :is="href ? 'a' : 'span'"></component>
  

  The built-in components can all be passed to is, but you must register them if you want to pass them by name. For example:

  <script>
  import { Transition, TransitionGroup } from 'kdu'
  
  export default {
    components: {
      Transition,
      TransitionGroup
    }
  }
  </script>
  
  <template>
    <component :is="isGroup ? 'TransitionGroup' : 'Transition'">
      ...
    </component>
  </template>
  

  Registration is not required if you pass the component itself to is rather than its name, e.g. in <script setup>.

  If k-model is used on a <component> tag, the template compiler will expand it to a modelValue prop and update:modelValue event listener, much like it would for any other component. However, this won't be compatible with native HTML elements, such as <input> or <select>. As a result, using k-model with a dynamically created native element won't work:

  <script setup>
  import { ref } from 'kdu'
  
  const tag = ref('input')
  const username = ref('')
  </script>
  
  <template>
    <!-- This won't work as 'input' is a native HTML element -->
    <component :is="tag" k-model="username" />
  </template>
  

  In practice, this edge case isn't common as native form fields are typically wrapped in components in real applications. If you do need to use a native element directly then you can split the k-model into an attribute and event manually.

• See also: Dynamic Components

<slot> #

Denotes slot content outlets in templates.

• Props

  interface SlotProps {
    /**
     * Any props passed to <slot> to passed as arguments
     * for scoped slots
     */
    [key: string]: any
    /**
     * Reserved for specifying slot name.
     */
    name?: string
  }
  

• Details

  The <slot> element can use the name attribute to specify a slot name. When no name is specified, it will render the default slot. Additional attributes passed to the slot element will be passed as slot props to the scoped slot defined in the parent.

  The element itself will be replaced by its matched slot content.

  <slot> elements in Kdu templates are compiled into JavaScript, so they are not to be confused with native <slot> elements.

• See also: Component - Slots