Table Of ContentReact From Scratch, Book 2: Hooks and forms
Build your porfolio with hooks and forms
Ajdin Imsirovic
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Thisversionwaspublishedon2023-01-19
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©2023AjdinImsirovic
Contents
Chapter0:Beforewestart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
0.1Disclaimer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
0.2Assumptions:Thingstohaveandknowbeforewestart . . . . . . . . . . . . . . . . . . . . 2
0.3Whatthisbookisabout? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Chapter1:UnderstandingtheuseStatehook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1Updatingacomponent’sstateusingtheuseStatehook . . . . . . . . . . . . . . . . . . . . . 6
Chapter2:FormsinReact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1FormsinReact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2WatchforinputchangesinReact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.3DetectingandhandlingtheonChangeeventonaninput . . . . . . . . . . . . . . . . . . . . 13
2.4Addingthebuilt-ineventobject . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.5Addingstatetotheforminput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.6TheproperwayofupdatingthestateobjectinReact . . . . . . . . . . . . . . . . . . . . . . 19
2.6Addingtheageinput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.7ControlledcomponentsinReact . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2.8Otherforminputs:radiobuttons,checkboxes,textareas,andselects . . . . . . . . . . . . 31
2.9FormsubmissionandpreventDefault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
2.10??? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Chapter3:RevisingcomponentsandJSX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.1asdf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Chapter4:Buildatodoapp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
4.1asdf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Chapter5:Popularformlibraries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.1asdf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Chapter6:Popularcomponentlibraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6.1asdf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Chapter7:Buildaportfolioapp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
7.1asdf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
CONTENTS
Chapter8:DeployaportfolioapptoNetlify. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
8.1asdf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Chapter 0: Before we start
0.1 Disclaimer
Before I even begin, note that this disclaimer is exactly the same as the one in the first book in this
bookseries.So,ifyou’vereaditinthepreviousbook,youcanskiptothenextsection.
Here goes the not-so-obligatory information that most people skip - but, I kept it really short and
sweet-underonepage.
Give it a try - I’ve tried my best to give you some context in this section and some of my thoughts
beforewegointothetopicofthe book.
Heregoes.
I’vetriedmybesttomakethisbookasuccess.
But,I’monlyanotherguy,and,likethevastmajorityofpeople,Idomakemistakes.
I hope that you, dear reader, will be able to appreciate the intention and the effort I have put into
writing this book. It is a product of many, many hours spent in front of a computer monitor, either
writingaboutcode,thinkingaboutcode,debuggingsomecode,orjustplaincoding.Idon’ttakethis
effortlightly.It’smysourceofpride-andthereasonwhyIfeelcompetenttowritethisbook.
I’d say I’m way past the 10 thousand hours of deliberate practice, the concept popularised by
MalcolmGladwellinhisbookOutliers.
So,whoamIandwhyshouldyoulistentomyadvice?
Well, I’ve already sort of answered that question above. I’m just another guy; a self-taught web
developerwhohasspentyearsmasteringmycraft.
In some parts of the web development world, I’m a seasoned veteran. In some other parts of it, I’m
anewbie.
I’mnotaknow-it-all,ifsuchapersonexists.
ButIhavededicatedalargepartofmyprofessionalcareertowritingtutorialsonwebdevelopment,
writingbooksaboutit,andthinkingaboutbestwaystotransferknowledge.Readinguponittoo!
SoI’dsayI’vebecomecompetenttoteachthissubject,basedonmyexperience.
Ifyoufindthisbooknottoyourliking,luckily,Leanpubhasareallygenerous60-dayreturnpolicy.
You might say that’s as risk-free as it can get. You can’t really say that it cost a fortune to begin
with, and the return policy is working in your favor anyway. So if you strongly feel that this book
isdoingyounogood-please,byallmeans,returnit.Noreasontogetworkedupaboutit,eitheron
mysideoronyours.
Chapter0: Beforewestart 2
Ifyouhavecomplaintsaboutthebook,[email protected]’lldo
mybesttodealwiththeissue.
Also,anycommentsandkindwords,aswellasharshcriticisms,areallwelcome.
Kindwordsfromreadersmeanalot.
Harsh criticisms, while I do find them usually not really neccessary, are a way to point me in the
rightdirection-andultimatelyhelpmebecomeabettertechnicalwriterandabetterdeveloper.
SoIthankyoueitherway.
0.2 Assumptions: Things to have and know before we
start
Ifyou’restartingthisbook,IexpectyouatleasthaveNode.jsandNPMinstalledonyourmachine.
IalsoexpectthatyouknoweverythingI’vecoveredinBook1ofthisbookseries.
Ideally, you’d have gone through the contents of that book and you’re ready to continue with this
one.
If you haven’t gone through the first book, perhaps some chapters in this one might be a bit
challenging.
Howcanyoudetermineifthat’sgoingtobethecaseforyou?
Well,here’sanoverviewofthingscoveredinBook1.
0.2.1 Things covered in Chapter 1: Simplest app
Inthischapter:
1. I’veshowntoyouhowtoinstallReactDeveloperToolsinyourbrowser.
2. I’ve introduced you to the create-react-app npm package, and I’ve shown to you how to use
thispackagetobuildaboilerplateReactapp.
3. I’ve explained all the files and folders in that boilerplate app, which goes a long way, because
nowyou’llunderstandthebasicstructureofanyReactappbuiltusingthispackage
4. I’veshownhowyoucanupdatethisstarterapptochangeitsoutput
0.2.2 Things covered in Chapter 2: Serving React from a CDN
Inthischapter,I’veshowntoyou:
1. HowtobuildaReactappwithoutabuildstep(usingCodepen.io)
Chapter0: Beforewestart 3
2. Howtorendermultipleheadingelements
3. HowtouseReact.createElement
4. TheDOMincontextofReact
5. Improvingyourapp’scodewithJSX
6. Howtheapptranspilingworks
7. ThedynamicnatureofJSX
0.2.3 Things covered in Chapter 3: Build React apps locally without
webpack
Inthischapter,I’veshowntoyouthefollowing:
1. Amorein-depthlookatReact.createElement
2. UnderstandingclassName
0.2.4 Things covered in Chapter 4: What is JSX
Inthischapter,I’veguidedyouthrough:
1. StructuringthereturnvaluesusingJSX
2. WorkingwithBabel
3. Usingdynamic(evaluated)valuesinJSX
4. WorkingwithnestedelementsinJSX
0.2.5 Things covered in Chapter 5: Components and props
Inthischapter,we’velearned:
1. HowtocodeacomponentinReact
2. Howtoexportacomponentandhowtoimportitintoanothercomponent
3. Usingasinglewrappingelementisamust
4. IntroductiontopropsinReact
5. Parent-childstructureofcomponentsinReact
0.2.6 Things covered in Chapter 6: Assets in React
Inthischapter,I’veshowntoyouhowtouseimagesandJSONinReactapps,andhowtoloopover
theJSONdatainsideacomponent.
Chapter0: Beforewestart 4
0.2.7 Things covered in Chapter 7: JSX and styling
Inthischapter,I’veshowntoyouhowtoworkwithstylesinJSX.Specifically,I’vecovered:
1. Importingstylesusingthelinkelement
2. Inlinestyleswithobjectliterals
3. Inlinestyleswithvariables
4. Composablestylesusingthespreadoperator
0.2.8 Things covered in Chapter 8: Build a static Bootstrap layout
Inthischapter,I’veshowntoyouhowtousetheBootstrapframeworkwithReact,withoutusinga
custom-madeframeworklike,forexample,React-Bootstrap.
I’vealsoshownhowtoworkwiththechildrenprop.
0.2.9 Things covered in Chapter 9: Looping over data
Inthischapter,I’veexplainedthetopicofloopingoverdata.I’veshownyouapracticalexampleof
mappingoverdataandforeachpieceofdata,renderingacomponent.Thatway,youavoidrepetition
andmakeyourcodeeasiertoreasonabout.
I’vealsoshowntoyouhowtorefactoracomponentsothat:
• itusesasingleprop,and
• usesobjectdestructuring
0.2.10 Things covered in Chapter 10: The very basics of data and
events in React
Inthischapter,I’vecoveredthefollowing:
1. Data
2. Statedata
3. Usingeventstoupdatestatedata
Chapter0: Beforewestart 5
0.2.11 Things covered in Chapter 11: Conditional rendering
Inthischapter,I’veshownyouhowtoconditionallyrender:
1. if-elsestatements
2. classNamesusingternaryoperators
3. adifferentvaluethantheoneinreceivedinthepropsobject
4. differentcomponents
5. componentsusingthe&&operator
I’vealsoshowntoyouhowto:
• extractthereturnvaluesasvaraibles
• renderingthemusingtheternaryoperator
0.3 What this book is about?
Ok,sonowthatIhavegivenyouanoverviewofthingscoveredinthepreviousbook,I’dliketogive
youaquickintroductiontothingsthatthisbookwillbediscussing.
First of all, since the title of this book series is “React from Scratch”, I’m indeed working on
introducingyoutoalltherelevant,importantconcepts,withoutthelearningcurvebeingtoosteep.
What that means is that, now you understand the very basics of React’s syntax and some of the
logic behind it, I’ll continue with the approach from the previous book: introducing a new concept,
isolatingitandsimplifyingitasmuchaspossible,andthengivingyouanappthatshowshowthat
conceptworksinpractice.
Thisshouldhelpyoubeconfidentinbuildingyourowncodethat’ssimilartotheoneshown.
Furthermore, this approach will allow us to build “multi-page” SPAs in the book that follows this
one.
However,weshouldn’tgetaheadofourselves.Fornow,thefocusisonunderstandinghooks,forms,
and some related concepts, without which it will be quite difficult to make some more advanced
Reactapps.
WelcometoBook2:HooksandForms.
Chapter 1: Understanding the
useState hook
1.1 Updating a component’s state using the useState
hook
Ideally,anappwouldconsistofstatelesscomponentsthroughandthrough.
Inotherwords,anidealappwouldbeastaticapp,wherecomponentscomposetogethertobuildan
appthathasnostate.
However,thatappwouldbeboring.Auserwouldnotbeabletointeractwithitotherthanreadthe
informationonthescreen-sincethatinformationwouldneverchange.
Thismeansthatalotofinteractivityinanappisactuallyuser-triggered.
Forexample,ifIwanttoallowausertoaddanitemtoacartonashoppingwebsite,I’llhaveto:
• addabuttonfortheusertopresstocompletesuchanaction
• reacttoeventstriggeredbysuchauseraction
Essentially, what this boils down to is that we need to code our React apps to handle user events
whichwillinturnupdateagivencomponent’sstate.
ThatmeansthatIneedto:
1. Setupstateinacomponent
2. Setupeventhandlers
3. Updatestateinsideeventhandlers
Inthefirstbookofthisbookseries,I’veshowntoyouabasicexampleofhowthisisdone.
Asastartingpoint,here’saquickreminder,Abasicadd-to-cartexample,pt3*.
Theentireappwasjustasinglecomponent -theApp component:
*https://codesandbox.io/s/a-basic-add-to-cart-example-pt-3-hqq0fr
