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Passing variable to Custom Svelte Web Component

I have created simple Custom Web Component using Svelte. It has been compiled and seems it should work well, but there is the difficulty. I'm trying to pass into prop some variable, but getting undefined all the time, but if I'm passing some string

Result.svelte component

<svelte:options tag="svelte-result" />

<script>
    export let result = {metadata: {}, transfers: []};
    export let string = 'no string';
</script>

<div class="result__wrapper">
    {string}
    <div class="result__metadata">
        <div>{result.metadata.offset}</div>
        <div>{result.metadata.limit}</div>
        <div>{result.metadata.total}</div>
    </div>
</div>

When it copiled I'm using it like

<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Svelte test</title>
  <script defer src="/svelte/wapi-client/svelte-component.js"></script>
  
</head>
<body>
  <div id="test"></div>
</body>

<script>
  const data = {
    metadata: {
      limit: 20,
      offset: 0,
      total: 311301
    },
    transfers: [
      {
        amount: "7.95",
        identifier: "9cd9901f-44a5-4436-9aef-880354bbe2e4"
      }
    ]
  };

  document.getElementById('test').innerHTML = `
    <svelte-result string="works" result=${data}></svelte-result>`;
</script>
</html>

data variable not passed to component, but string passed and shown correctly... What Am I doing wrong? How can I pass data variable into component ?

Solution

  • You can't pass objects as attributes to custom elements. You need to stringify your object before passing it.

    index.html

    ...
document.getElementById('test').innerHTML = `
    <svelte-result string="works" result=${JSON.stringify(data)}></svelte-result>`;
...

    Foo.svelte

    <svelte:options tag="svelte-result" />

<script>
    export let result = {metadata: {}, transfers: []};
    export let string = 'no string';
        
    $: _result = typeof result === 'string' ? JSON.parse(result) : result;
</script>

<div class="result__wrapper">
    {string}
    <div class="result__metadata">
        <div>{_result.metadata.offset}</div>
        <div>{_result.metadata.limit}</div>
        <div>{_result.metadata.total}</div>
    </div>
</div>