separate price setting behaviour

src/front/pages/offers.js

@@ -18,15 +18,6 @@ class PriceDisplay {
   }
 
   render() {
-
-    const marketPrice = this.priceProvidingCallback()
-    const marketPriceString = formatNumberWithSpaces(marketPrice);
-    const offerPriceString = formatNumberWithSpaces(
-      Math.round(marketPrice * (
-        1 + this.premiumProvidingCallback()
-      ))
-    );
-
     const container = document.createElement("div");
     container.id = "premium-price-display-area";
     
@@ -36,7 +27,7 @@ class PriceDisplay {
     
     const offerSpan = document.createElement("span");
     offerSpan.id = "offer-price";
-    offerSpan.textContent = offerPriceString;
+    this.offerPriceSpan = offerSpan
     
     offerParagraph.appendChild(offerSpan);
     offerParagraph.append("€/BTC");
@@ -47,7 +38,7 @@ class PriceDisplay {
     
     const marketSpan = document.createElement("span");
     marketSpan.id = "market-price";
-    marketSpan.textContent = marketPriceString;
+    this.marketPriceSpan = marketSpan
     
     marketParagraph.appendChild(marketSpan);
     marketParagraph.append("€/BTC)");
@@ -55,12 +46,25 @@ class PriceDisplay {
     container.appendChild(offerParagraph);
     container.appendChild(marketParagraph);
 
+    this.updatePrices();
+
     this.element = container;
     this.parentElement.appendChild(this.element);
   
   }
 
-  update() {}
+  updatePrices() {
+    const marketPrice = this.priceProvidingCallback()
+    const marketPriceString = formatNumberWithSpaces(marketPrice);
+    const offerPriceString = formatNumberWithSpaces(
+      Math.round(marketPrice * (
+        1 + this.premiumProvidingCallback()
+      ))
+    );
+
+    this.marketPriceSpan.innerText = marketPriceString;
+    this.offerPriceSpan.innerText = offerPriceString;
+  }
 }
 
 function offersPage() {