Params

How params flows

1. router.parseLocation() walks window.location.pathname minus basePath. It strips locale-code segments and app-path segments, leaving currentRoute.
2. router.getRouteByPath(currentRoute) walks the registered route list and runs matchUrl(route.path, currentRoute, matcher) on each.
3. The matcher returns [ok, params]. The matched route is the first hit; its params are placed on router.params.
4. <RouterWrapper> passes router.params as the params prop to the page component (and to every middleware via MiddlewareProps).

router.add("/users/:id", UserPage);

function UserPage({ params, localeCode }: { params: { id: string }; localeCode: string }) {
  return <p>User {params.id}</p>;
}

router.params is also readable globally outside the React tree.

URL matcher

Default matcher:

import type { UrlMatcher } from "@mongez/react-router";

const urlPatternMatcher: UrlMatcher = (pattern) => {
  // handles :name, :name?, :name+, :name*
  return { regexp, keys: [{ name }] };
};

Override with path-to-regexp (or anything else):

import { pathToRegexp } from "path-to-regexp";

setRouterConfigurations({
  urlMatcher: (pattern) => {
    const keys: Array<{ name: string }> = [];
    const regexp = pathToRegexp(pattern, keys);
    return { regexp, keys };
  },
});

The matcher is called once per route per pattern; results are memoized in a WeakMap keyed by the matcher function reference (so swapping the matcher via setRouterConfigurations({ urlMatcher: ... }) starts with a fresh cache).

Query string

import { queryString } from "@mongez/react-router";

queryString.all();
queryString.parse(searchParams: string);  // explicit query string
queryString.get(key: string, defaultValue?: any);
queryString.toString();                   // current window.location.search.substring(1)
queryString.toQueryString(params: object | string);
queryString.update(params, reRender?: boolean);

Default parser semantics

queryString.parse("page=2&sort=name&tags[]=a&tags[]=b&nested[k]=v");
// → { page: 2, sort: "name", tags: ["a", "b"], nested: { k: "v" } }

• Numeric-looking values come back as number (e.g. page=2 → page: 2).
• key[]=v1&key[]=v2 becomes { key: ["v1", "v2"] }. With a single occurrence, it’s still an array ({ key: ["v1"] }).
• key[sub]=v becomes { key: { sub: "v" } }. Nested objects compose: a[b][c]=v → { a: { b: { c: "v" } } }.

queryString.toQueryString(...)

queryString.toQueryString({ a: 1, b: [2, 3], nested: { x: 1 } });
// → "a=1&b[]=2&b[]=3&nested[x]=1"

queryString.update(...)

queryString.update({ page: 2, sort: "date" });            // replaceState, no render
queryString.update({ page: 2 }, /* reRender */ true);     // also calls refresh()
queryString.update("page=2&sort=date");                   // raw string accepted

Note: update replaces the entire query string, not merges. Pass the full object you want represented.

Swap parsers

import qs from "qs";

setRouterConfigurations({
  queryString: {
    objectParser: (search) => qs.parse(search),
    stringParser: (obj) => qs.stringify(obj),
  },
});

Useful when integrating with a library that has its own query-string convention (e.g. PHP-style nesting, comma-separated arrays).