add Node.js fallback for file util

Check whether XMLHttpRequest is defined and if not use the Node.js built-in fetch method.

Author: PiotrNap

apps/playground/src/pages/apis/txbuilder/governance/registration.tsx

@@ -34,7 +34,7 @@ function Left() {
 
   let codeAnchor = ``;
   codeAnchor += `async function getMeshJsonHash(url: string) {\n`;
-  codeAnchor += `  var drepAnchor = getFile(url);\n`;
+  codeAnchor += `  var drepAnchor = await getFile(url);\n`;
   codeAnchor += `  const anchorObj = JSON.parse(drepAnchor);\n`;
   codeAnchor += `  return hashDrepAnchor(anchorObj);\n`;
   codeAnchor += `}\n`;
@@ -129,7 +129,7 @@ function Right() {
   const [anchorUrl, setAnchorUrl] = useState<string>("");
 
   async function getMeshJsonHash(url: string) {
-    var drepAnchor = getFile(url);
+    var drepAnchor = await getFile(url);
     const anchorObj = JSON.parse(drepAnchor);
     const anchorHash = hashDrepAnchor(anchorObj);
     return anchorHash;

apps/playground/src/pages/apis/txbuilder/governance/update.tsx

@@ -65,7 +65,7 @@ function Right() {
   const [anchorUrl, setAnchorUrl] = useState<string>("");
 
   async function getMeshJsonHash(url: string) {
-    var drepAnchor = getFile(url);
+    var drepAnchor = await getFile(url);
     const anchorObj = JSON.parse(drepAnchor);
     const anchorHash = hashDrepAnchor(anchorObj);
     return anchorHash;

packages/mesh-common/src/utils/file.ts

@@ -1,6 +1,11 @@
-export function getFile(url: string) {
-  var Httpreq = new XMLHttpRequest();
-  Httpreq.open("GET", url, false);
-  Httpreq.send(null);
-  return Httpreq.responseText;
+export async function getFile(url: string) {
+  if (typeof XMLHttpRequest !== "undefined") {
+    var Httpreq = new XMLHttpRequest();
+    Httpreq.open("GET", url, false);
+    Httpreq.send(null);
+    return Httpreq.responseText;
+  } else {
+    const res = await fetch(url);
+    return res.text();
+  }
 }