review_tools.module

<?php

/*This module provides a button to create reviews 
 * and prevents users to review a movie/TV series multiple times */



/*Print the name of the node type*/
function node_type_name()
{
    if ($node = menu_get_object('node', 1)) {
        $type = $node->type;
        if ($type == 'movie') {
            $node_name = 'movie';
        } elseif ($type == 'tv_series') {
            $node_name = 'TV series';
        }
    }
    return $node_name;
}

/*Get the NID of the node being viewed*/
function get_nid()
{
    if ($node = menu_get_object('node', 1)) {
        $nid = $node->nid;
    }
    return $nid;
}

/*Check if the user has already reviewed the movie/TV series being viewed*/
function review_tools_check_review()
{
    global $user;
    $nid        = get_nid();
    $uid        = $user->uid;
    $raw_result = db_query("SELECT field_data_field_movie.entity_id AS 'review_id', field_data_field_movie.field_movie_target_id AS 'movie_id',
 COUNT(field_data_field_movie.entity_id) AS 'total' FROM field_data_field_movie INNER JOIN node 
 ON field_data_field_movie.entity_id = node.nid WHERE (node.uid = :uid AND field_data_field_movie.field_movie_target_id = :nid);", array(
        ':nid' => $nid,
        ':uid' => $uid
    ));
    $result     = $raw_result->fetchObject();
    $total            = $result->total;
    $review_id        = $result->review_id;
    $already_reviewed = array();
    if ($total != 0) {
        $already_reviewed[0] = TRUE;
        $already_reviewed[1] = $review_id;
    } else {
        $already_reviewed[0] = FALSE;
    }
    return $already_reviewed;
}

/*Implementation of hook_block_info*/
function review_tools_block_info()
{
    $blocks['review_tools'] = array(
        'info' => t('Review tools block'),
        'cache' => DRUPAL_NO_CACHE
    );
    return $blocks;
}

/*Implementation oh hook_block_view*/
function review_tools_block_view($delta = '')
{
    switch ($delta) {
        case 'review_tools':
            $block['subject'] = t('Review Tools');
            $check            = review_tools_check_review();
            if ($check[0]) {
                $block['content'] = '<b>You have already rated/reviewed this ' . node_type_name() . '</b><br><a class="review-tools-button" href="/node/' . $check[1] . '/edit">Edit your review</a>';
            } else {
                $block['content'] = '<a class="review-tools-button" href="/node/add/review?field_movie=' . get_nid() . '">Review this ' . node_type_name() . '</a>';
            }
            break;
    }
    return $block;
}

/*Implementation of hook_form_alter to prevent malicious users from reviewing movies/TV series multiple times via URL*/
function review_tools_form_alter(&$form, &$form_state, $form_id)
{
    if ($form_id == 'review_node_form' && arg(1) == 'add') {
        $movie_nid = $form_state['entityreference_prepopulate']['node']['review']['field_movie'][0];
        global $user;
        $uid              = $user->uid;
        $raw_result       = db_query("SELECT field_data_field_movie.entity_id AS 'review_id', field_data_field_movie.field_movie_target_id AS 'movie_id',
 COUNT(field_data_field_movie.entity_id) AS 'total' FROM field_data_field_movie INNER JOIN node 
 ON field_data_field_movie.entity_id = node.nid WHERE (node.uid = :uid AND field_data_field_movie.field_movie_target_id = :nid);", array(
            ':nid' => $movie_nid,
            ':uid' => $uid
        ));
        $result           = $raw_result->fetchObject();
        $already_reviewed = array();
        $total            = $result->total;
        $review_id        = $result->review_id;
        $movie_id         = $result->movie_id;
        if ($total != 0) {
            $form['#disabled'] = TRUE;
            drupal_set_message('No way! You have already rated/reviewed this movie! You can ' . l('Edit', '/node/' . $review_id . '/edit') . ' it if you want.');
            drupal_goto('/node/' . $movie_id);
        }
    }
}