Pages and file-based routing in Vue - Step-by-Step Execution

Concept Flow - Pages and file-based routing

Start: App loads

↓

Router reads URL

↓

Look for matching file in /pages

↓

File found

↓

Load component

↓

Render page component

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User navigates -> Router updates URL -> Repeat

The router reads the URL, finds the matching page file, loads its component, and renders it. If no file matches, it shows a 404 page.

Execution Sample

Vue

pages/
  index.vue
  about.vue

// URL: /about
// Router loads about.vue component and renders it

This code shows how the router picks the about.vue file to render the About page when the URL is /about.

Execution Table

Step	URL	Router Action	File Matched	Component Loaded	Rendered Output
1	/	Reads URL '/'	index.vue	Index component	Home page content
2	/about	Reads URL '/about'	about.vue	About component	About page content
3	/contact	Reads URL '/contact'	No matching file	404 component	404 Not Found page
4	User clicks link to '/'	Reads URL '/'	index.vue	Index component	Home page content

💡 Routing stops when a matching page file is found or 404 page is shown if no match.

Variable Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4
currentURL	''	'/'	'/about'	'/contact'	'/'
matchedFile	null	index.vue	about.vue	null	index.vue
loadedComponent	null	Index	About	404	Index
renderedPage	null	Home page	About page	404 page	Home page

Key Moments - 2 Insights

Why does the router show a 404 page when the URL does not match any file?

Because the router looks for a file matching the URL in the /pages folder. If it finds none, it loads the 404 component as shown in step 3 of the execution_table.

How does the router know which component to load for a URL?

It matches the URL path to a file name in the /pages folder. For example, '/about' matches about.vue, so it loads the About component as in step 2.

Visual Quiz - 3 Questions

Look at the execution_table. What component is loaded when the URL is '/'?

A 404 component

B About component

C Index component

D Contact component

💡 Hint

Check the 'Component Loaded' column for Step 1 where URL is '/'.

At which step does the router show the 404 page?

A Step 3

B Step 2

C Step 1

D Step 4

💡 Hint

Look at the 'Rendered Output' column to find when '404 Not Found page' appears.

If a new file 'contact.vue' is added to /pages, what will happen at Step 3?

A Router will still show 404 page

B Router will load Contact component

C Router will load About component

D Router will load Index component

💡 Hint

Refer to how the router matches URL to file names in the execution_table steps.

Concept Snapshot

Pages and file-based routing in Vue:
- URL path matches a file in /pages folder
- Matching file's component loads and renders
- No match shows 404 page
- Navigation updates URL and repeats routing
- Simple, automatic page management

Full Transcript

When the app starts, the router reads the current URL. It looks for a file in the /pages folder that matches the URL path. If it finds a matching file, it loads that file's component and renders it as the page. If no file matches, the router loads a 404 Not Found page. When the user clicks links, the URL changes and the router repeats this process to load the correct page component. This system makes routing simple by using the file names as routes automatically.