29823fe495
* Expanded the solution for the 'Get Route Parameter Input from the Client' challenge * Expanded the guide for the 'Use body-parser to Parse POST Requests' challenge * Rewritten guide for the 'Serve JSON on a Specific Route' challenge and fixed source link * Expanded the guide for the 'Serve Static Assets' challenge * Expanded solution to the 'Get Query Parameter Input from the Client' challenge and fixed links to source file * Added solution to the 'Chain Middleware to Create a Time Server' challenge and fixed link to source file * Rewrite the 'Start a Working Express Server' challenge * Expanded the guide for 'Expand Your Project with External Packages from npm' * Added reference to semantic versioning in 'Add a Version to Your package.json' * fix/remove-links+fix-solutions * fix/remove-more-links
54 lines
1.3 KiB
Markdown
54 lines
1.3 KiB
Markdown
---
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title: Chain Middleware to Create a Time Server
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---
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## Chain Middleware to Create a Time Server
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<!-- The article goes here, in GitHub-flavored Markdown. Feel free to add YouTube videos, images, and CodePen/JSBin embeds -->
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Similar to the last challenge, but now we are chaining 2 functions together. It seems complicated, but it's just JavaScript.
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### Hint
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Instead of responding with the time we can also add any arbitrary property to the request object and pass it to the next function by calling the `next()` method. This is trivial, but it makes for a decent example. The code will looks like this:
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```javascript
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app.get("/now", (req, res, next) => {
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// adding a new property to req object
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// in the middleware function
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req.string = "example";
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next();
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}, (req, res) => {
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// accessing the newly added property
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// in the main function
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res.send(req.string);
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});
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```
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### Solution
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```javascript
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app.get("/now", (req, res, next) => {
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req.time = new Date().toString();
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next();
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}, (req, res) => {
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res.send({
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time: req.time
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});
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});
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```
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You can also declare the middleware beforehand to use in multiple routes as shown below:
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```javascript
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const middleware = (req, res, next) => {
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req.time = new Date().toString();
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next();
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};
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app.get("/now", middleware, (req, res) => {
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res.send({
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time: req.time
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});
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});
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```
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