2 files changed, 66 insertions, 0 deletions
diff --git a/FrontEnd/src/app/utilities/rxjs.ts b/FrontEnd/src/app/utilities/rxjs.ts
new file mode 100644
index 00000000..0730b899
--- /dev/null
+++ b/FrontEnd/src/app/utilities/rxjs.ts
@@ -0,0 +1,14 @@
+import { OperatorFunction } from "rxjs";
+import { catchError } from "rxjs/operators";
+
+export function convertError<T, NewError>(
+  oldErrorType: { new (...args: never[]): unknown },
+  newErrorType: { new (): NewError }
+): OperatorFunction<T, T> {
+  return catchError((error) => {
+    if (error instanceof oldErrorType) {
+      throw new newErrorType();
+    }
+    throw error;
+  });
+}
diff --git a/FrontEnd/src/app/utilities/url.ts b/FrontEnd/src/app/utilities/url.ts
new file mode 100644
index 00000000..17ead5b2
--- /dev/null
+++ b/FrontEnd/src/app/utilities/url.ts
@@ -0,0 +1,52 @@
+//copied from https://stackoverflow.com/questions/5999118/how-can-i-add-or-update-a-query-string-parameter
+export function updateQueryString(
+  key: string,
+  value: undefined | string | null,
+  url: string
+): string {
+  const re = new RegExp("([?&])" + key + "=.*?(&|#|$)(.*)", "gi");
+  let hash;
+
+  if (re.test(url)) {
+    if (typeof value !== "undefined" && value !== null) {
+      return url.replace(re, "$1" + key + "=" + value + "$2$3");
+    } else {
+      hash = url.split("#");
+      url = hash[0].replace(re, "$1$3").replace(/(&|\?)$/, "");
+      if (typeof hash[1] !== "undefined" && hash[1] !== null) {
+        url += "#" + hash[1];
+      }
+      return url;
+    }
+  } else {
+    if (typeof value !== "undefined" && value !== null) {
+      const separator = url.includes("?") ? "&" : "?";
+      hash = url.split("#");
+      url = hash[0] + separator + key + "=" + value;
+      if (typeof hash[1] !== "undefined" && hash[1] !== null) {
+        url += "#" + hash[1];
+      }
+      return url;
+    } else {
+      return url;
+    }
+  }
+}
+
+export function applyQueryParameters<T>(url: string, query: T): string {
+  if (query == null) return url;
+
+  for (const [key, value] of Object.entries(query)) {
+    if (typeof value === "string") url = updateQueryString(key, value, url);
+    else if (typeof value === "number")
+      url = updateQueryString(key, String(value), url);
+    else if (typeof value === "boolean")
+      url = updateQueryString(key, value ? "true" : "false", url);
+    else if (value instanceof Date)
+      url = updateQueryString(key, value.toISOString(), url);
+    else {
+      console.error("Unknown query parameter type. Param: ", value);
+    }
+  }
+  return url;
+}