%% generate tags start %%
#obsidian #software-engineering
%% generate tags end %%
#software-engineering/svelte #obsidian/plugin
**Use a [[svelte action]]**: Instead of using `onMount`, consider creating a Svelte action. Actions are functions that can be used to add behavior to DOM elements.
Here's an example of how you can create and use a Svelte action for the dropdown:
```svelte
<script>
// ... other imports ...
function dropdownAction(node) {
const dropdown = new DropdownComponent(node);
dropdown.addOption("value1", "Option 1");
dropdown.addOption("value2", "Option 2");
// ... more options ...
dropdown.onChange((value) => {
// Handle dropdown value change
});
return {
destroy() {
// Cleanup if needed
}
};
}
</script>
<div class="incomplete-files-utils">
<div id="dropdown-container" use:dropdownAction></div>
<!-- other buttons -->
</div>
```
In this code, `dropdownAction` is a Svelte action that initializes the dropdown when the div is created in the DOM. This ensures that the dropdown is created at the correct time in the component lifecycle.
## You Need to Use Update if Your want Your Obsidian Component to Be Responsive to State Changes
you can use svelte action or lifecycle hooks to do this.
Svelte actions and lifecycle hooks serve different purposes and can be used together to build interactive components. Here's a brief explanation of each and how they can be used to manage DOM elements like buttons with dynamic content:
### Svelte Actions:
- Actions in Svelte are functions that can be applied to DOM elements. They are used to add behavior to elements when they are first created.
- An action is given control over a node when it is first created, and it returns an object that can contain a `destroy` method which is called when the node is removed from the DOM.
- Actions are ideal for adding complex interactions or integrations with non-Svelte libraries to elements.
Here's how you might use a Svelte action to update your button:
```ts
<script>
// ...imports and other script code
function buttonAction(node, issue) {
// Initialize button logic here
const button = new ButtonComponent(node);
button.setTooltip(`${issue.file.path}: ${issue.title}`);
// Set up the button's click action
button.onClick(() => {
if (issue.heading) goToHeading(issue.file, issue.heading);
else goToFile(issue.file);
});
// Function to update the button's content
function updateIcon() {
const iconType = issue.type === INCOMPLETE_REASON_TYPE.EMPTY_CONTENT
? checkEmptyContent.icon
: issue.type === INCOMPLETE_REASON_TYPE.EMPTY_CONTENT_HEADING
? checkEmptyContentHeading.icon
: checkIncompleteSyntax.icon;
// Clear previous content and append the new SVG
node.textContent = '';
node.appendChild(iconType); // Assuming iconType is a DOM node
}
updateIcon();
return {
update(newIssue) {
// This function is called with the new value whenever the value changes
issue = newIssue;
updateIcon();
},
destroy() {
// Clean up the button when the element is removed
button.remove();
},
};
}
</script>
<div use:buttonAction={issue}></div>
```
In the code above, `buttonAction` is the Svelte action that is applied to a `div`. It initializes the button component, sets the tooltip, click handler, and manages the SVG icon. The action also returns an `update` method, which Svelte calls whenever the `issue` parameter changes, keeping the button's icon up-to-date.
### Lifecycle Hooks:
- Lifecycle hooks are functions that are called at different points in a component's life. They are used to run code at specific times during a component's creation, update, and destruction.
- They're useful when you want to integrate with external libraries or perform actions that should happen at a certain time in the lifecycle, like setting up or cleaning up after a component.
```ts
<script lang="ts">
import { onMount, afterUpdate } from 'svelte';
import type { IncompleteFile, IncompleteReason } from "@/SettingsSchemas";
// ... other imports
export let issue: IncompleteReason & { file: IncompleteFile };
let button: ButtonComponent;
// Function to update the button
const updateButton = (buttonEl: HTMLElement, issue: IncompleteReason & { file: IncompleteFile }) => {
buttonEl.classList.add(
"is-clickable",
"incomplete-files-reason",
"issue-icon"
);
buttonEl.dataset.reason = issue.type;
// Set SVG content without using innerHTML
const svgContent =
issue.type === INCOMPLETE_REASON_TYPE.EMPTY_CONTENT
? checkEmptyContent.icon
: issue.type === INCOMPLETE_REASON_TYPE.EMPTY_CONTENT_HEADING
? checkEmptyContentHeading.icon
: checkIncompleteSyntax.icon;
const parser = new DOMParser();
const svgDocument = parser.parseFromString(svgContent, 'image/svg+xml');
const svgElement = svgDocument.rootElement;
// Clear previous content and append the new SVG
buttonEl.textContent = '';
buttonEl.appendChild(svgElement);
};
onMount(() => {
button = new ButtonComponent(node);
button.setTooltip(`${issue.file.path}: ${issue.title}`);
button.onClick(() => {
if (issue.heading) goToHeading(issue.file, issue.heading);
else goToFile(issue.file);
});
updateButton(button.buttonEl, issue);
});
afterUpdate(() => {
updateButton(button.buttonEl, issue);
});
// Cleanup if necessary
onDestroy(() => {
button?.remove();
});
</script>
<div style="display:inline-block;" />
```
### Choosing Between Actions and Lifecycle Hooks:
For your use case, if the icon needs to be updated reactively based on changes to the `issue`, a Svelte action could be a cleaner approach as it encapsulates all the logic related to the button, including initialization, updates, and destruction. It also reduces the amount of code in the main component script and can be reused across different components.
If the initialization and update logic of your button are complex and need to be tightly integrated with the component's lifecycle, then using lifecycle hooks alongside actions could be advantageous. However, in most cases, actions alone should suffice to encapsulate the behavior associated with DOM elements.
In conclusion, you can certainly use a Svelte action to achieve your goal with less code and potentially more reusability. The action approach encapsulates the behavior and keeps your component clean, focusing only on what the component should render.