White screen when activating plugin that sends form via WordPress

Question

I am creating a plugin in WordPress that will send some data via email. When I activate the plugin, I'm getting a white screen.

I set define('WP_DEBUG', true); in wp-config.php but no error messages are displayed.

Here is the code for my plugin:

<?php
/* 
Plugin Name: Formulario Cotação
Plugin URI: http://solutionsagencia.com.br
Description: Plugin para cotação em 2 passos.
Version: 0.0.1
Author: Wendell Christian
Author URI: http://solutionsagencia.com.br
License: GPLv2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
*/


// Verifica se não existe nenhum classe com o mesmo nome
if ( ! class_exists('FormularioCotacao') ) {

    class FormularioCotacao
    {


    public function __construct() {
        /* Adiciona o shortcode */
        add_shortcode( 'cotacao', array( $this, 'ExibirTexto' ) );
    }

    /**
     * Este é um método simples que irá exibir o texto do nosso shortcode
     */
    public function ExibirTexto () {
        $FormularioCotacaoURL = WP_CONTENT_URL;
        $FormularioCotacaoURL = WP_CONTENT_URL.'/plugins/'.plugin_basename( dirname(__FILE__)).'/';
        return "<div class='principal-form' id='principal-form'>
        <form type='post' action='' id='cadastraForm'>
        <div class='col-md-65'><div class='col-md-34'><input type='text' name='nome' id='nome' class='campo-form' placeholder='Nome' maxlength='50'></div>
        <div class='col-md-34-2'><input type='email' name='email' id='email' class='campo-form' placeholder='Email' maxlength='120'/></div>
        <input type='hidden' name='action' value='addCustomer'/>
        <div class='col-md-30'><button type='submit' id='enviarform' class='botao-enviar'><span class='icone-cadastrar'></span>Efetue sua simulação</button>
        </div>
        </div>

        </div>
        <div id='feedback'></div>
        <div id='passo2form' class='passo2form'></div>

";
    }

} 

/* Carrega a classe */
$FormularioCotacao_settings = new FormularioCotacao();

} // class_exists


function addCustomer(){

    global $wpdb;

    $nome = trim($_POST['nome']);
    $email = trim($_POST['email']); 

    if($wpdb->insert('wp_formclientes',array(
        'nome'=>$nome,
        'email'=>$email
    ))===FALSE){

    echo "Error";

    }
    else {

    //mensagem de sucesso

    }
    die();
    }
    add_action('wp_ajax_addCustomer', 'addCustomer');
    add_action('wp_ajax_nopriv_addCustomer', 'addCustomer'); // not really needed


    /*Enviando email completo*/

if( isset($_POST['nome']) && ($_POST['email'])){


    $para = "email@email.com";
    $assunto = "Assunto" . $nome;
    $conteudo =
    "<b>Nome:</b> {$nome}" .
    "<b>Email:</b> {$email}" .

    $headers = array(
        'Reply-To' => $name . '<' . $email . '>',
    );

}

add_filter( 'wp_mail_content_type', 'set_html_content_type' );

require('http://solutionsagencia.com.br/comparasaude/wp-load.php');

$status = wp_mail( $para, $assunto, $conteudo );


remove_filter( 'wp_mail_content_type', 'set_html_content_type' );

function set_html_content_type() {
    return 'text/html';
}


if ( $status ){
    echo "sucesso";
} else {
}



function FormularioCotacao_addJS() {
    $FormularioCotacaoURL = WP_CONTENT_URL.'/plugins/'.plugin_basename( dirname(__FILE__)).'/';
    wp_register_style('estilo', $FormularioCotacaoURL . 'css/estilo.css');
    wp_enqueue_style('estilo', $FormularioCotacaoURL . 'css/estilo.css');
}

add_action('wp_print_scripts', 'FormularioCotacao_addJS');

Answer 1

you should remove:

require('http://solutionsagencia.com.br/comparasaude/wp-load.php');

and use:

require(ABSPATH.'wp-includes/pluggable.php');

p.s. I advice you, these executions should be hooked in 'init', like:

add_action('init', function(){

    $para = "email@email.com";
    $assunto = "Assunto" . $nome;
    $conteudo =
    "<b>Nome:</b> {$nome}" .
    "<b>Email:</b> {$email}" .

    $headers = array(
        'Reply-To' => $name . '<' . $email . '>',
    );

  $status = wp_mail( $para, $assunto, $conteudo );

  remove_filter( 'wp_mail_content_type', 'set_html_content_type' );

  if ( $status ){
    echo "sucesso";
  } else {
  }

});

Answer 2

Throws an error for me alright:

Warning: require(): http:// wrapper is disabled in the server configuration by allow_url_include=0 in /var/www/europeanvoice/wp-content/plugins/test.php on line 101

Warning: require(http://solutionsagencia.com.br/comparasaude/wp-load.php): failed to open stream: no suitable wrapper could be found in /var/www/europeanvoice/wp-content/plugins/test.php on line 101

Fatal error: require(): Failed opening required 'http://solutionsagencia.com.br/comparasaude/wp-load.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/europeanvoice/wp-content/plugins/test.php on line 101

Basically, you can't do this:

require('http://solutionsagencia.com.br/comparasaude/wp-load.php');

Answer 3

Make sure to configure PHP to display errors. You can turn on DB logging in WordPress by adding this line to the wp-config.php file:

define( 'WP_DEBUG_LOG', true );

Starting on line 84, you've got some code that is not being fired via a hook. You should wrap that code in a function and fire it on a hook to ensure that you're controlling the timing of the code being fired.

On line 101 your're doing an include for a PHP file over HTTP, which is usually not a good idea and it won't work on some server configurations anyway depending on allow_url_include settings:

require('http://solutionsagencia.com.br/comparasaude/wp-load.php');

$status = wp_mail( $para, $assunto, $conteudo );

I'm really not sure why you'd be including wp-load.php, AJAX maybe? If so, then check out the Codex article on AJAX in Plugins.