1 files changed, 35 insertions, 0 deletions
diff --git a/Timeline/ClientApp/src/app/helper.ts b/Timeline/ClientApp/src/app/helper.ts
new file mode 100644
index 00000000..b48829b5
--- /dev/null
+++ b/Timeline/ClientApp/src/app/helper.ts
@@ -0,0 +1,35 @@
+//copied from https://stackoverflow.com/questions/5999118/how-can-i-add-or-update-a-query-string-parameter
+export function updateQueryString(
+  key: string,
+  value?: string | null,
+  url?: string
+): string {
+  if (!url) url = window.location.href;
+  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;
+    }
+  }
+}