debugging

 how to debugging and error finding in React 

step 01: debugger lagao har jagah agar debugger nai rook raha hai means data hi nai aa raha hai

step 02: console.log lagao ki data aa raha hai ki nai 

step03: sab cheej dekho thik se kiya hai import ya nai har jagah par jahan par nai hua hai wahan par karke dekho

step 04: kafi jagah undefined ki error aati hai 

step 05: backend mein data tab jata hai jab aap fetch ya axios se api call karte ho 

step 06: action mein jo user.push hai woh app,js mein path diya gaya hoga and upar usko import kiya gaya hoga.

step 07: backend par api ja rahi hai ki nai aur ja rahi hai toh wahan se kya success aa rah ha ki nai...

jahan api hum call karte hain network se waheen se check karo ki yeh data call ho bhi raha hai ki nai...

service se call hoti hai api..

step 08:  network mein jo api jati hai usmein dekho response kya aa raha hai..

step 09: jo red mein hai network mein emans usmein error hai..

step 10:  user && user.items &&  replace karo user.items se isse yeh hota hai ki user.items ko lega agar user hain toh 

step 11: 

condition check karo ki sab sahi likha hai condition ke andar handlesubmit mein....uske andar debugger lagao pehle agar condition false ho rahi hai toh debugger nahi rukega.

step 12:map of null ki error aa rahi hogi then

{leaveapplications && leaveapplications.leave_applications && leaveapplications.leave_applications.map

pehle yeh tha 

{leaveapplications  && leaveapplications.leave_applications.map

note;

network se request jati hui dikhti hai backend par aur rails se response ata hua dikhta hai

step 1: 

debugger lagate hain

1 condition ke andar :agar nai rook raha hai toh upar lagate hain condition ke

2 condition ke upar lagate hain..

3 jab debugger rook jata hai toh if ke andar jo conditions lagi hain unko check karte hain...

4. true false method lagakar sabhi conditions ko ek sath bhi check kar sakte hain..

step2:

attendance mein option dete hain present ka toh ata hai nai toh nai ata hai...

how to debugging and error finding in Rails

In controller Api -

if @vehicle.update!(vehicle_params)

update!   from update 

models mein association dekho bani hai ki nahi hasmany and belongs to

controller mein byebug lagakar dekho aap

permits mein dekho sab kuch theek theek permit ho raha hai ki nai controller mein

optional_true lagakar dekho ki theek se kam kar raha hai ki nai 

agar kuch theek karne ke bad bhi rails mein nai aa raha hai toh fir server restart kar lo aap

schema mein school_id hai ki nai hai

controller mein jo method upar de rakha hai wohi neeche de rakha hai ki nai hai

@leavve_application to @leave_application

  

Imp;

In rails this method is repeating and many times this error comes due to 

@

      @homeworks = current_user && current_user.superadmin_role? ? Homework.all : current_school.homeworks

    @homeworks = @homeworks.paginate(:page => params[:page], :per_page => 10)    

    @homeworks = @homeworks.map{|m| m.as_json.merge(section: m.section.name, standard: m.standard.standard) } 

right side will come to the left side in this...