getting undefined index with a post.

It would seem that there is no proveedor field in the submitted data. You can temporarily dump the request payload to see what you are receiving.

public function store(Request $request)
{
    dump($request->all());

    $validator = Validator::make(
        $request->all(),
        [

        ]
    );

    // etc...

It probably is not appropriate in this case, but more generally, you can mitigate these types of errors and exceptions using the data_get() helper, which allows for setting a default value in the event that there is no key:

data_get($request->all(), 'proveedor', null);

Thanks for your reply.

with the dump($request->all()); Now Im able make a post but the data isnt saved or displayed.

You missed my point above, what do you see in the dumped request data - is there a proveedor key in the array?

Yes. {"data":[{"id":1,"proveedor":"OGmv6PfuBO","marca":"N8IojsEYMc","contacto":"RuagUqRhP0","telefono":1463235513,"email":"xIPTD221m6@gmail.com","pais":"vda9eFPoOY","direccion":"SQFZdYJ0sP","calidad":"RoMKm9HB72","pedidos":"foL8W9iLup"},{"id":2,"proveedor":"dWHZKInbOW","marca":"GooUCnerT3","contacto":"pAJkPcMr8G","telefono":1572260665,"email":"[email protected]","pais":"j8Vvy4Hoe2","direccion":"501tS7jd0p","calidad":"FGz2U0hXng","pedidos":"hWLgDSzVsC"}]}

So, your payload is an array nested under a data key, whereas your code expects to create a single Supplier resource with the parameters to do so such as proveedor (and others) to be at the top level.

So the question is; do you want to create one or more than one Supplier?

More than one. could be unlimited

Ok that is not achievable from your current code; you need to iterate over this incoming request data creating a Supplier for each set of data:

public function store(Request $request)
{
    $validator = Validator::make(
        $request->all(),
        [
            // ensure that the validation rules expects the data in the format you have dumped above
        ]
    );
    
    if ($validator->fails()) {
        return response()->json(['errors' => $validator->errors()], 403); // 422 is more appropriate
    }
    
    $suppliers = collect($request->input('data'))->map(function($params) {
        return Suppliers::create([
            'proveedor' => $params['proveedor'],
            'code' => strtolower($params['proveedor']) . time(), // Just to make sure this value is unique
            'contacto' => $params['contacto'],
            'telefono' => $params['telefono'],
            'email' => $params['email'],
            'pais' => $params['pais'],
            'direccion' => $params['direccion'],
            'calidad' => $params['calidad'],
            'pedidos' => $params['pedidos'],
        ]);
    });

    return new SuppliersResource($suppliers);
}

Here you are putting the contents of the $request->input('data') into a collection so that we can create the Suppliers collection to pass to the SupplierResource

Thank you so much for your help. looks like Im able to POST using postman but when I submit the form Im getting a 405 error.

The console shows this message

PUT http://127.0.0.1:8000/api/suppliers/ 405 (Method Not Allowed)

Well, you have said it yourself you are sending a POST request in Postman, but a PUT request in the browser; remove the _method field from the form - this might be a @method('PUT') directive - it is unnecessary. Ensure the form method attribute**is**POST`

Thanks again but my form don't have a method:

<el-dialog :title="formTitle" :visible.sync="supplierFormVisible">
  <div class="form-container">
    <el-form ref="supplierForm" :model="currentSupplier" label-position="left" label-width="150px" style="max-width: 500px;">
      <el-form-item label="Proveedor" prop="proveedor">
        <el-input v-model="currentSupplier.proveedor" />
      </el-form-item>
      <el-form-item label="Marca" prop="marca">
        <el-input v-model="currentSupplier.marca" />
      </el-form-item>
      <el-form-item label="Contacto" prop="contacto">
        <el-input v-model="currentSupplier.contacto" />
      </el-form-item>
      <el-form-item label="Telefono" prop="telefono">
        <el-input v-model="currentSupplier.telefono" />
      </el-form-item>
      <el-form-item label="Email" prop="email">
        <el-input v-model="currentSupplier.email" />
      </el-form-item>
      <el-form-item label="Pais" prop="pais">
        <el-input v-model="currentSupplier.pais" />
      </el-form-item>
      <el-form-item label="Direccion" prop="direccion">
        <el-input v-model="currentSupplier.direccion" />
      </el-form-item>
      <el-form-item label="Calidad" prop="calidad">
        <el-input v-model="currentSupplier.calidad" />
      </el-form-item>
      <el-form-item label="Pedidos" prop="pedidos">
        <el-input v-model="currentSupplier.pedidos" />
      </el-form-item>
    </el-form>
    <div slot="footer" class="dialog-footer">
      <el-button @click="supplierFormVisible = false">
        Cancel
      </el-button>
      <el-button type="primary" @click="handleSubmit()">
        Confirm
      </el-button>
    </div>
  </div>
</el-dialog>

I don't use element-ui myself, is there a handler method (e.g. onSubmit) for the form where the form submission is handled, and a request verb/method specified?

Cant see anything.. Look online but no luck.

You'll need to work out why a PUT request is being submitted; or replace the Vue component with something you can grok more easily.

Someone told me that specify the method will be the solution but still getting the error.

<el-form ref="supplierForm" :model="currentSupplier" label-position="left" label-width="150px">

Noticed that the put comes from the api/resources.js file.

update(id, resource) { return request({ url: '/' + this.uri + '/' + id, method: 'post', data: resource, }); }

If I change the method to post, I don't get the error but don't update or create the new supplier.