• do
InterCourses
CoursesBlogs
0
← DOM Manipulation with JavaScript
○The page is a tree○Exercise: follow the document reference○Load a script when the page is ready○Exercise: initialize a deferred script○Find one element by id or CSS selector○Exercise: select a notice and label○Compare DOM properties, HTML attributes, and node types○Exercise: inspect a room input and its nodes✦Module Quiz
○Find every match with querySelectorAll○Exercise: label every trail stop○Move from a child to its relatives○Exercise: trace a nested card○Check for missing elements and search within a card○Exercise: update only the chosen card○Compare a live HTMLCollection with a static NodeList○Exercise: safely expand a live collection✦Module Quiz
○Safe text and HTML○Exercise: render a safe notice○Read and change link attributes○Exercise: update an accessible link○Data attributes and conditional text○Exercise: announce session availability○Boolean attributes and DOM properties○Exercise: unlock a volunteer sign-up✦Module Quiz
○Add, remove, and check classes○Exercise: mark a favourite card○Toggle a panel accessibly○Exercise: toggle the help panel○Inline styles, classes, and hidden○Exercise: style and hide a notice○Change a CSS custom property from JavaScript○Exercise: change a workshop card accent✦Module Quiz
○Create and Append a Text Node○Exercise: Add a Reading List Item○Place Nodes Before and Between○Exercise: Order the Workshop Agenda○Remove, Replace, and Clear Safely○Exercise: Refresh a Museum Display○Clone a Card and Insert a Batch○Exercise: Clone Two Exhibit Cards✦Module Quiz
○Listen for Clicks with a Named Handler○Exercise: Check Library Hours○Event Target, Current Target, and Delegation○Exercise: Delegate Pantry Actions○Keyboard Events Without Trapping Keys○Exercise: Search the Recipe Box○Once, Remove, and Bubble○Exercise: Control Workshop Notifications✦Module Quiz
○Read a field while someone types○Build a live name preview○Handle submit without leaving the page○Validate a library request○Keep a selection in sync on change and reset○Sync a preference and its reset state○Read multiple checked values with FormData○Build a checkbox-based garden request✦Module Quiz
○Filter a list as someone types○Build a live trail finder○Toggle an accessible disclosure○Build a guide menu disclosure○Create and remove items with one delegated listener○Build a neighborhood task board○Sort a workshop table with accessible buttons○Build an accessible sortable resource table✦Module Quiz
○Read selectable cards and detail updates○Build directory cards and a selected profile○Trace live search and an empty state○Add live search to the community directory○Trace safe additions and delegated removal○Add and remove community directory cards✦Module Quiz
○Read and update a live itinerary○Build the workshop itinerary○Add a validated item through a form○Add a workshop session○Filter and remove live entries○Finish the workshop planner✦Module Quiz
○Fetch JSON and render safe text○Exercise: load recipe cards○Handle loading, empty, and failed responses○Exercise: handle alert states●Build a query with URLSearchParams○Exercise: search the catalog○Abort outdated requests○Exercise: keep the latest result✦Module Quiz
○Load a dashboard from an offline API fixture○Build an events dashboard○Query a dashboard with URLSearchParams○Add event search to the dashboard○Retry requests without stale results○Finish a resilient event dashboard✦Module Quiz

Build a query with URLSearchParams

A seed library needs a search that can include spaces and symbols. The preview is intentionally powered by an explicit in-page mock fetch, so it works offline and never claims to show live data.

Typing tea & honey into a search box is not the same as appending ?q=tea & honey to a URL. & separates query parameters and spaces need encoding. URLSearchParams accepts the input as a value and serializes it safely; it is URL encoding, not HTML escaping. When displaying the returned string, still use textContent.

javascript
const params = new URLSearchParams({ q: "red beans & rice" });
const url = `/api/seeds?${params.toString()}`;
// q=red+beans+%26+rice; the server decodes the original value.
const response = await mockFetch(url);
const seeds = await response.json();

The mock parses the actual URL you pass and returns fixed in-page seed data. Try the search mint & lime; the preview shows a match and the URL line shows %26 instead of an unescaped ampersand. This is a local request simulation, not a real API search. A real fetch(url) can use the same URL construction when a same-origin API exists; cross-origin servers must explicitly permit CORS.

The next exercise moves that exact encoding technique to a catalog, where the names and DOM targets are different.

Loading editor…
READY
intercourses
javascript