svelte keep updating store var without clicking to update - svelte-3

Question

My app automatically update $content value without me clicking on buttons. I know it is a simple question, but I can't find out why, I'm learning svelte.
App.svelte
<script>
import { content } from './store.js';
import Item from './Item.svelte';
$content = [{ id:0,obj: "Fell free to browse any category on top." }];
function addContent(value) {
$content = [{ id:0,obj: value}]
}
</script>
<li><button on:click={addContent("Home Page")}>Home</button></li>
<li><button on:click={addContent("Products Page")}>Products</button></li>
<div class="Content">
<p>Fell free to browse any category on top.</p>
{#each $content as item}
<p><svelte:component this={Item} objAttributes={item} /></p>
{/each}
</div>
store.js
import { writable } from 'svelte/store';
export let content = writable({});
Item.svelte
<script>
import { fade } from 'svelte/transition';
export let objAttributes = {};
</script>
<p transition:fade>
{objAttributes.obj}
{#if objAttributes.otherattrib}<em>{objAttributes.otherattrib}</em>{/if}
</p>

Answer 1

This is because your on:click events are defined wrongly.
The on:click takes as argument a function like this
<button on:click={functionGoesHere}>
or, if you want it inlined
<button on:click={() => { }>
What happens in your case is that you directly call a function and the result of this function will then be called when the button is clicked. You can see that in this example:
<script>
function createFn() {
return () => console.log('logging this')
}
</script>
<button on:click={createFn}>Click here</button>
in this example the function () => console.log('logging this') will be attached the button.
So to come back to your code, this is easily fixed by making it a function instead of a function call:
<li><button on:click={() => addContent("Home Page")}>Home</button></li>