如何在Svelte中调用CodeMirror组件内部导出的update函数？

Ah, I see the issue here—your current approach won’t work because Svelte handles component-exported functions differently than regular module exports. Let me break down the correct way to access and use that update function:

Step 1: Get a reference to the CodeMirror component instance #

Instead of trying to import the update function directly, you need to grab a reference to the mounted CodeMirror component using bind:this. Here's how to do that in your parent component:

<script>
  import CodeMirror from '../../../../components/CodeMirror.svelte';
  
  // Declare a variable to hold the component instance
  let codeMirrorInstance;

  // Example function to trigger the update
  function updateCode(newCode) {
    // Make sure the instance exists before calling the method
    if (codeMirrorInstance) {
      codeMirrorInstance.update(newCode);
    }
  }
</script>

<!-- Bind the component instance to our variable -->
<CodeMirror bind:this={codeMirrorInstance} />

<!-- Example button to test the update -->
<button on:click={() => updateCode('console.log("Updated content!")')}>
  Update Code
</button>

Why your initial approach failed #

When you export a function inside a Svelte component, it doesn’t become a top-level module export—it’s a method attached to the component’s instance. That means you can’t import it directly like you would a regular utility function; you need to interact with the actual mounted component instance to access those methods.

Additional Notes #

• Always check if the instance exists before calling methods on it (like we did with if (codeMirrorInstance)), especially if you might try to call update before the component has finished mounting.
• If you need to trigger the update when the component first mounts, wrap the call in onMount from Svelte:

  import { onMount } from 'svelte';
  
  onMount(() => {
    if (codeMirrorInstance) {
      codeMirrorInstance.update('Initial code content');
    }
  });
  

内容的提问来源于stack exchange，提问作者khalD