fix dapp preloading for localhost

- [CORE-1121]

src/app/ens.ts

@@ -184,6 +184,23 @@ export async function getContentHashForAddress(address: string): Promise<string>
   return bytes32ToIpfsHash(result);
 }
 
+/**
+ * Sets the ens cache for a ens address with a loaded dbcp description.
+ *
+ * @param      {string}  address  ens address
+ * @param      {any}     dbcp     dbcp.public
+ */
+export function setEnsCache(address: string, dbcp: any): void {
+  // set ens cache to speed up initial loading
+  if (dbcp.dapp.type === 'cached-dapp') {
+    ensCache[address] = JSON.stringify(dbcp);
+  } else {
+    delete ensCache[address];
+  }
+
+  window.localStorage['evan-ens-cache'] = JSON.stringify(ensCache);
+}
+
 /**
  * Resolves the content behind a ens address.
  *
@@ -213,16 +230,8 @@ export async function resolveContent(address: string) {
         const ipfsResult = await ipfsCatPromise(ipfsHash);
         // parse the result
         const dbcp = JSON.parse(ipfsResult).public;
-
-        // set ens cache to speed up initial loading
-        if (dbcp.dapp.type === 'cached-dapp') {
-          ensCache[address] = JSON.stringify(dbcp);
-        } else {
-          delete ensCache[address];
-        }
-
+        setEnsCache(address, dbcp);
         // save ens cache
-        window.localStorage['evan-ens-cache'] = JSON.stringify(ensCache);
         return dbcp;
       } catch (ex) {
         const errMsg = `Could not parse content of address ${address}: ${ipfsHash} (${ex.message})`;

src/app/routing.ts

@@ -141,6 +141,7 @@ export async function onRouteChange(): Promise<void> {
       const split = window.location.hash.replace(/#\/|#/g, '').split('?')[0].split('/');
       split.forEach((subEns: string) => {
         if (subEns !== activeRootENS && ensCache[subEns]) {
+          utils.log(`preloading ${subEns} dapp`);
           loadDApp(subEns);
         }
       });

src/systemjs/plugins/ens.ts

@@ -18,10 +18,9 @@
 */
 
 import * as utils from '../../app/utils';
-import System from '../index';
 import { getQueryParameters } from '../../app/routing';
 import { ipfsCatPromise } from '../../app/ipfs';
-import { resolveContent, parseToValidEnsAddress } from '../../app/ens';
+import { resolveContent, parseToValidEnsAddress, setEnsCache } from '../../app/ens';
 
 export default function(System: any) {
   // libraries that should be cached
@@ -36,31 +35,41 @@ export default function(System: any) {
    */
   const getDefinitionFromEns = async function(ensAddress: string, domain: string) {
     // remove domain from the end of the ensAddress to get the dapp name
-    let split = parseToValidEnsAddress(ensAddress).split('.');
+    const split = parseToValidEnsAddress(ensAddress).split('.');
     const dappName = split.slice(0, split.length - 1).join('.');
 
     // get correct ens address and check if a cached ens is availabled
     const validEnsAddress = parseToValidEnsAddress(ensAddress);
     let dbcp;
+    let updateEnsCache = false;
 
     try {
       if (utils.isDevAvailable(dappName) && ensAddress.indexOf('0x') !== 0) {
         // load json and resolve it as stringified
         dbcp = await System.import(`dapps/${dappName}/dbcp.json!json`);
+        updateEnsCache = true;
       } else if (validEnsAddress.indexOf('Qm') === 0) {
         dbcp = await ipfsCatPromise(validEnsAddress);
+        updateEnsCache = true;
       } else {
         dbcp = await resolveContent(validEnsAddress);
       }
     } catch (ex) {
       console.dir(ex);
     }
 
+    // parse dbcp to the correct format
     if (typeof dbcp === 'string') {
       dbcp = JSON.parse(dbcp);
     }
+    dbcp = dbcp && dbcp.public ? dbcp.public : dbcp;
 
-    return JSON.stringify(dbcp && dbcp.public ? dbcp.public : dbcp) || '';
+    // update ens cache for local / ipfs loaded dbcp
+    if (updateEnsCache && dbcp) {
+      setEnsCache(ensAddress, dbcp);
+    }
+
+    return JSON.stringify(dbcp) || '';
   };
 
   /**