Author: Anik Babu

In a Svelte component, when it comes to rendering HTML you can work with some specific syntax to craft the UI you need at every stage of the application lifecycle. In particular, we’ll now explore conditional structures. The problem is this: you want to be able to look at a value/expression, and if that points… Continue reading Svelte:Conditional Logic in Templates

offsetWidth, offsetHeight, clientWidth, clientHeight can be bound, read only, on any block level HTML element, excluding void tags (like br) and elements that are set to be inline (display: inline). Get a reference to the HTML element in JavaScript bind:this is a special kind of binding that allows you to get a reference to an HTML element and bind it to… Continue reading svelte:Read-only bindings

bind:value also works for the select form field to get the selected value automatically assigned to the value of a variable: The cool thing is that if you generate options dynamically from an array of objects, the selected option is now an object, not a string: See example: https://svelte.dev/repl/7e06f9b7becd4c57880db5ed184ea0f3 select also allows the multiple attribute:

Checkboxes and radio inputs (input elements with type=”checkbox” or type=”radio”) allow those 3 bindings: bind:checked bind:group bind:indeterminate bind:checked allows us to bind a value to the checked state of the element: bind:group is handy with checkboxes and radio inputs, because those are very often used in groups. Using bind:group you can associate a JavaScript array to a list of checkboxes, and have it… Continue reading Svelte:Checkboxes and radio buttons

Using Svelte you can create a two-way binding between data and the UI. Many other Web frameworks can provide two-way bindings, it’s a very common pattern. They are especially useful with forms. bind:value Let’s start with the most common form of binding you’ll often use, which you can apply using bind:value. You take a variable from… Continue reading Svelte Bindings

Every component in Svelte fires several lifecycle events that we can hook on, to help us implement the functionality we have in mind. In particular, we have onMount fired after the component is rendered onDestroy fired after the component is destroyed beforeUpdate fired before the DOM is updated afterUpdate fired after the DOM is updated We can schedule functions… Continue reading Svelte Lifecycle Events

Slots are a handy way to let you define components that can be composed together. And vice versa, depending on your point of view, slots are a handy way to configure a component you are importing. Here’s how they work. In a component, you can define a slot using the <slot /> (or <slot></slot>) syntax. Here’s a Button.svelte the component… Continue reading Svelte Slots

Svelte stores are a great tool to handle your app state when components need to talk to each other without passing props around too much. You must first import writable from svelte/store: and create a store variable using the writable() function, passing the default value as the first argument: This can be put into a separate file which you can… Continue reading Svelte stores

However, there are cases where props are not practical. Perhaps 2 components are so distant in the components tree that we’d have to move state up to the top-level component. In this case, another technique can be used called context API. It’s ideal when you want to let multiple components communicate with descendants, but you don’t want… Continue reading The context API

You can import a Svelte component into any other component using the syntax import ComponentName from ‘componentPath’: The path is relative to the current component path. ./ means “this same folder”. You’d use ../ to go back one folder, and so on. Once you do so, you can use the newly imported component in the markup, like an HTML tag:… Continue reading Svelte Props