data not updating on laravel 5.4? - laravel-5.4

Question

Here is my edit.blade file.Please notice on From tag action attribute.Is this Ok?
#extends('admin_theme.master')
#section('title','Add Category')
#section('content')
#if(Auth::check())
<script>
function validselect(){
var ind=document.getElementById('my_select').selectedIndex;
if(ind==0){
alert("please select an Valid Option");
}
}
</script>
<div class="forms">
<div class=" form-grids form-grids-right">
<div class="widget-shadow " data-example-id="basic-forms">
<div class="form-title">
<h4>Ready To ADD:</h4>
</div>
<div class="form-body">
<form class="form-horizontal" action={{route('category.update',$singledata->id)}} method="put">
{{ csrf_field() }}
<div class="form-group">
<label for="inputEmail3" class="col-sm-2 control-label">Category Name</label>
<div class="col-sm-9">
<input class="form-control" id="inputEmail3" placeholder="Name" type="text" value="{{$singledata->name}}" name="name">
</div>
</div>
<div class="form-group">
<label for="inputPassword3" class="col-sm-2 control-label">Status</label>
<div class="col-sm-9">
<Select class="form-control" id="my_select"onchange="validselect()" name="status">
<option>Select availability</option>
<option value="1" #if($singledata->status==1){{"selected"}} #endif >Active</option>
<option value="0" #if($singledata->status==0){{"selected"}} #endif>DeActive</option>
</Select>
</div>
</div>
<div class="form-group">
</div>
<div class="col-sm-offset-2"> <button type="submit" class="btn btn-default" >Update</button>
</div>
</form>
</div>
</div>
</div>
</div>
#endif
#endsection
Here is my update method in controller and here the inputted data from edit page not found in $request object.I changed the html method like as PUT or PATCH but no luck :)
public function update(Request $request, $id)
{
$allinput=$request->all();
// dd($allinput);
// dd($allinput);
$data=Category::findorfail($id);
$data->update($allinput);
return view('admin_theme.dynamic_files.category.allCategory');
}
here is my route
<?php
Route::get('/', function () {
return view('my_theme.index');
});
Auth::routes();
Route::get('/admin', 'HomeController#index');
Route::resource('category','CategoryController');
In before (doing CRUD) the store() method works fine the problem is when i update data...i am stuck on this,please help me on this.Thanks in advance

Answer 1

Atlast solved
adding method="POST" in form tag and also add below line after {{csrf_field()}}
<input name="_method" type="hidden" value="PATCH">
but why this line need ?dont know.If anyone make me understand i will be thankfull :)