[+] Input validation

AquaNet/src/pages/Transfer/InputTextShort.svelte

@@ -3,11 +3,14 @@
   export let value: string
   export let placeholder: string
   export let flex: number = 60
+
+  export let validate: (value: string) => boolean = () => true
 </script>
 
 <div class="field" style="flex: {flex}">
   <label for={desc}>{desc}</label>
-  <input type="text" placeholder={placeholder} bind:value={value} id="{desc}" on:change />
+  <input type="text" placeholder={placeholder} bind:value={value} id="{desc}" on:change
+    class:error={value && !validate(value)}/>
 </div>
 
 <style lang="sass">