spell + filtering + urlParams

docs/.vuepress/theme/util/filterHelpers.js

@@ -0,0 +1,52 @@
+export function setUrlParams (urlParam, list) {
+  var params = ""
+  for (var i = 0; i < list.length; i++) {
+    if (params !== "") {
+      params = params + ","
+    }
+    params = params + list[i]
+  }
+  if (list.length == 0) {
+    params = "null"
+  }
+  history.replaceState(null, null, setUrlParameter(window.location.href, urlParam, params))
+}
+
+export function setUrlParameter (url, key, value) {
+    var key = encodeURIComponent(key),
+        value = encodeURIComponent(value);
+
+    var baseUrl = url.split('?')[0],
+        newParam = key + '=' + value,
+        params = '?' + newParam;
+
+    let urlQueryString = '';
+    if (url.split('?')[1] == undefined){ // if there are no query strings, make urlQueryString empty
+    } else {
+        urlQueryString = '?' + url.split('?')[1];
+    }
+
+    // If the "search" string exists, then build params from it
+    if (urlQueryString) {
+        var updateRegex = new RegExp('([\?&])' + key + '[^&]*');
+        var removeRegex = new RegExp('([\?&])' + key + '=[^&;]+[&;]?');
+
+        if (typeof value === 'undefined' || value === null || value === "") { // Remove param if value is empty
+            params = urlQueryString.replace(removeRegex, "$1");
+            params = params.replace(/[&;]$/, "");
+
+        } else if (urlQueryString.match(updateRegex) !== null) { // If param exists already, update it
+            params = urlQueryString.replace(updateRegex, "$1" + newParam);
+
+        } else if (urlQueryString=="") { // If there are no query strings
+            params = '?' + newParam;
+        } else { // Otherwise, add it to end of query string
+            params = urlQueryString + '&' + newParam;
+        }
+    }
+
+    // no parameter was set so we don't need the question mark
+    params = params === '?' ? '' : params;
+
+    return baseUrl + params;
+}