<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Entry query builder.
*
* @package mod_glossary
* @copyright 2015 Frédéric Massart - FMCorz.net
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* Entry query builder class.
*
* The purpose of this class is to avoid duplicating SQL statements to fetch entries
* which are very similar with each other. This builder is not meant to be smart, it
* will not out rule any previously set condition, or join, etc...
*
* You should be using this builder just like you would be creating your SQL query. Only
* some methods are shorthands to avoid logic duplication and common mistakes.
*
* @package mod_glossary
* @copyright 2015 Frédéric Massart - FMCorz.net
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @since Moodle 3.1
*/
class mod_glossary_entry_query_builder {
/** Alias for table glossary_alias. */
const ALIAS_ALIAS = 'ga';
/** Alias for table glossary_categories. */
const ALIAS_CATEGORIES = 'gc';
/** Alias for table glossary_entries_categories. */
const ALIAS_ENTRIES_CATEGORIES = 'gec';
/** Alias for table glossary_entries. */
const ALIAS_ENTRIES = 'ge';
/** Alias for table user. */
const ALIAS_USER = 'u';
/** Include none of the entries to approve. */
const NON_APPROVED_NONE = 'na_none';
/** Including all the entries. */
const NON_APPROVED_ALL = 'na_all';
/** Including only the entries to be approved. */
const NON_APPROVED_ONLY = 'na_only';
/** Including my entries to be approved. */
const NON_APPROVED_SELF = 'na_self';
/** @var array Raw SQL statements representing the fields to select. */
protected $fields = array();
/** @var array Raw SQL statements representing the JOINs to make. */
protected $joins = array();
/** @var string Raw SQL statement representing the FROM clause. */
protected $from;
/** @var object The glossary we are fetching from. */
protected $glossary;
/** @var int The number of records to fetch from. */
protected $limitfrom = 0;
/** @var int The number of records to fetch. */
protected $limitnum = 0;
/** @var array List of SQL parameters. */
protected $params = array();
/** @var array Raw SQL statements representing the ORDER clause. */
protected $order = array();
/** @var array Raw SQL statements representing the WHERE clause. */
protected $where = array();
/**
* Constructor.
*
* @param object $glossary The glossary.
*/
public function __construct($glossary = null) {
$this->from = sprintf('FROM {glossary_entries} %s', self::ALIAS_ENTRIES);
if (!empty($glossary)) {
$this->glossary = $glossary;
$this->where[] = sprintf('(%s.glossaryid = :gid OR %s.sourceglossaryid = :gid2)',
self::ALIAS_ENTRIES, self::ALIAS_ENTRIES);
$this->params['gid'] = $glossary->id;
$this->params['gid2'] = $glossary->id;
}
}
/**
* Add a field to select.
*
* @param string $field The field, or *.
* @param string $table The table name, without the prefix 'glossary_'.
* @param string $alias An alias for the field.
*/
public function add_field($field, $table, $alias = null) {
$field = self::resolve_field($field, $table);
if (!empty($alias)) {
$field .= ' AS ' . $alias;
}
$this->fields[] = $field;
}
/**
* Adds the user fields.
*
* @return void
*/
public function add_user_fields() {
$userfieldsapi = \core_user\fields::for_userpic();
$fields = $userfieldsapi->get_sql('u', false, 'userdata', '', false)->selects;
$this->fields[] = $fields;
}
/**
* Internal method to build the query.
*
* @param bool $count Query to count?
* @return string The SQL statement.
*/
protected function build_query($count = false) {
$sql = 'SELECT ';
if ($count) {
$sql .= 'COUNT(\'x\') ';
} else {
$sql .= implode(', ', $this->fields) . ' ';
}
$sql .= $this->from . ' ';
$sql .= implode(' ', $this->joins) . ' ';
if (!empty($this->where)) {
$sql .= 'WHERE (' . implode(') AND (', $this->where) . ') ';
}
if (!$count && !empty($this->order)) {
$sql .= 'ORDER BY ' . implode(', ', $this->order);
}
return $sql;
}
/**
* Count the records.
*
* @return int The number of records.
*/
public function count_records() {
global $DB;
return $DB->count_records_sql($this->build_query(true), $this->params);
}
/**
* Filter a field using a letter.
*
* @param string $letter The letter.
* @param string $finalfield The SQL statement representing the field.
*/
protected function filter_by_letter($letter, $finalfield) {
global $DB;
$letter = core_text::strtoupper($letter);
$len = core_text::strlen($letter);
$sql = $DB->sql_substr(sprintf('upper(%s)', $finalfield), 1, $len);
$this->where[] = "$sql = :letter";
$this->params['letter'] = $letter;
}
/**
* Filter a field by special characters.
*
* @param string $finalfield The SQL statement representing the field.
*/
protected function filter_by_non_letter($finalfield) {
global $DB;
$alphabet = explode(',', get_string('alphabet', 'langconfig'));
list($nia, $aparams) = $DB->get_in_or_equal($alphabet, SQL_PARAMS_NAMED, 'nonletter', false);
$sql = $DB->sql_substr(sprintf('upper(%s)', $finalfield), 1, 1);
$this->where[] = "$sql $nia";
$this->params = array_merge($this->params, $aparams);
}
/**
* Filter the author by letter.
*
* @param string $letter The letter.
* @param bool $firstnamefirst Whether or not the firstname is first in the author's name.
*/
public function filter_by_author_letter($letter, $firstnamefirst = false) {
$field = self::get_fullname_field($firstnamefirst);
$this->filter_by_letter($letter, $field);
}
/**
* Filter the author by special characters.
*
* @param bool $firstnamefirst Whether or not the firstname is first in the author's name.
*/
public function filter_by_author_non_letter($firstnamefirst = false) {
$field = self::get_fullname_field($firstnamefirst);
$this->filter_by_non_letter($field);
}
/**
* Filter the concept by letter.
*
* @param string $letter The letter.
*/
public function filter_by_concept_letter($letter) {
$this->filter_by_letter($letter, self::resolve_field('concept', 'entries'));
}
/**
* Filter the concept by special characters.
*
* @return void
*/
public function filter_by_concept_non_letter() {
$this->filter_by_non_letter(self::resolve_field('concept', 'entries'));
}
/**
* Filter non approved entries.
*
* @param string $constant One of the NON_APPROVED_* constants.
* @param int $userid The user ID when relevant, otherwise current user.
*/
public function filter_by_non_approved($constant, $userid = null) {
global $USER;
if (!$userid) {
$userid = $USER->id;
}
if ($constant === self::NON_APPROVED_ALL) {
// Nothing to do.
} else if ($constant === self::NON_APPROVED_SELF) {
$this->where[] = sprintf('%s != 0 OR %s = :toapproveuserid',
self::resolve_field('approved', 'entries'), self::resolve_field('userid', 'entries'));
$this->params['toapproveuserid'] = $USER->id;
} else if ($constant === self::NON_APPROVED_NONE) {
$this->where[] = sprintf('%s != 0', self::resolve_field('approved', 'entries'));
} else if ($constant === self::NON_APPROVED_ONLY) {
$this->where[] = sprintf('%s = 0', self::resolve_field('approved', 'entries'));
} else {
throw new coding_exception('Invalid constant');
}
}
/**
* Filter by concept or alias.
*
* This requires the alias table to be joined in the query. See {@link self::join_alias()}.
*
* @param string $term What the concept or aliases should be.
*/
public function filter_by_term($term) {
$this->where[] = sprintf("(%s = :filterterma OR %s = :filtertermb)",
self::resolve_field('concept', 'entries'),
self::resolve_field('alias', 'alias'));
$this->params['filterterma'] = $term;
$this->params['filtertermb'] = $term;
}
/**
* Convenience method to get get the SQL statement for the full name.
*
* @param bool $firstnamefirst Whether or not the firstname is first in the author's name.
* @return string The SQL statement.
*/
public static function get_fullname_field($firstnamefirst = false) {
global $DB;
if ($firstnamefirst) {
return $DB->sql_fullname(self::resolve_field('firstname', 'user'), self::resolve_field('lastname', 'user'));
}
return $DB->sql_fullname(self::resolve_field('lastname', 'user'), self::resolve_field('firstname', 'user'));
}
/**
* Get the records.
*
* @return array
*/
public function get_records() {
global $DB;
return $DB->get_records_sql($this->build_query(), $this->params, $this->limitfrom, $this->limitnum);
}
/**
* Get the recordset.
*
* @return moodle_recordset
*/
public function get_recordset() {
global $DB;
return $DB->get_recordset_sql($this->build_query(), $this->params, $this->limitfrom, $this->limitnum);
}
/**
* Retrieve a user object from a record.
*
* This comes handy when {@link self::add_user_fields} was used.
*
* @param stdClass $record The record.
* @return stdClass A user object.
*/
public static function get_user_from_record($record) {
return user_picture::unalias($record, null, 'userdataid', 'userdata');
}
/**
* Join the alias table.
*
* Note that this may cause the same entry to be returned more than once. You might want
* to add a distinct on the entry id.
*
* @return void
*/
public function join_alias() {
$this->joins[] = sprintf('LEFT JOIN {glossary_alias} %s ON %s = %s',
self::ALIAS_ALIAS, self::resolve_field('id', 'entries'), self::resolve_field('entryid', 'alias'));
}
/**
* Join on the category tables.
*
* Depending on the category passed the joins will be different. This is due to the display
* logic that assumes that when displaying all categories the non categorised entries should
* not be returned, etc...
*
* @param int $categoryid The category ID, or GLOSSARY_SHOW_* constant.
*/
public function join_category($categoryid) {
if ($categoryid === GLOSSARY_SHOW_ALL_CATEGORIES) {
$this->joins[] = sprintf('JOIN {glossary_entries_categories} %s ON %s = %s',
self::ALIAS_ENTRIES_CATEGORIES, self::resolve_field('id', 'entries'),
self::resolve_field('entryid', 'entries_categories'));
$this->joins[] = sprintf('JOIN {glossary_categories} %s ON %s = %s',
self::ALIAS_CATEGORIES, self::resolve_field('id', 'categories'),
self::resolve_field('categoryid', 'entries_categories'));
} else if ($categoryid === GLOSSARY_SHOW_NOT_CATEGORISED) {
$this->joins[] = sprintf('LEFT JOIN {glossary_entries_categories} %s ON %s = %s',
self::ALIAS_ENTRIES_CATEGORIES, self::resolve_field('id', 'entries'),
self::resolve_field('entryid', 'entries_categories'));
} else {
$this->joins[] = sprintf('JOIN {glossary_entries_categories} %s ON %s = %s AND %s = :joincategoryid',
self::ALIAS_ENTRIES_CATEGORIES, self::resolve_field('id', 'entries'),
self::resolve_field('entryid', 'entries_categories'),
self::resolve_field('categoryid', 'entries_categories'));
$this->params['joincategoryid'] = $categoryid;
}
}
/**
* Join the user table.
*
* @param bool $strict When strict uses a JOIN rather than a LEFT JOIN.
*/
public function join_user($strict = false) {
$join = $strict ? 'JOIN' : 'LEFT JOIN';
$this->joins[] = sprintf("$join {user} %s ON %s = %s",
self::ALIAS_USER, self::resolve_field('id', 'user'), self::resolve_field('userid', 'entries'));
}
/**
* Limit the number of records to fetch.
* @param int $from Fetch from.
* @param int $num Number to fetch.
*/
public function limit($from, $num) {
$this->limitfrom = $from;
$this->limitnum = $num;
}
/**
* Normalise a direction.
*
* This ensures that the value is either ASC or DESC.
*
* @param string $direction The desired direction.
* @return string ASC or DESC.
*/
protected function normalize_direction($direction) {
$direction = core_text::strtoupper($direction);
if ($direction == 'DESC') {
return 'DESC';
}
return 'ASC';
}
/**
* Order by a field.
*
* @param string $field The field, or *.
* @param string $table The table name, without the prefix 'glossary_'.
* @param string $direction ASC, or DESC.
*/
public function order_by($field, $table, $direction = '') {
$direction = self::normalize_direction($direction);
$this->order[] = self::resolve_field($field, $table) . ' ' . $direction;
}
/**
* Order by author name.
*
* @param bool $firstnamefirst Whether or not the firstname is first in the author's name.
* @param string $direction ASC, or DESC.
*/
public function order_by_author($firstnamefirst = false, $direction = '') {
$field = self::get_fullname_field($firstnamefirst);
$direction = self::normalize_direction($direction);
$this->order[] = $field . ' ' . $direction;
}
/**
* Convenience method to transform a field into SQL statement.
*
* @param string $field The field, or *.
* @param string $table The table name, without the prefix 'glossary_'.
* @return string SQL statement.
*/
protected static function resolve_field($field, $table) {
$prefix = constant(__CLASS__ . '::ALIAS_' . core_text::strtoupper($table));
return sprintf('%s.%s', $prefix, $field);
}
/**
* Simple where conditions.
*
* @param string $field The field, or *.
* @param string $table The table name, without the prefix 'glossary_'.
* @param mixed $value The value to be equal to.
*/
public function where($field, $table, $value) {
static $i = 0;
$sql = self::resolve_field($field, $table) . ' ';
if ($value === null) {
$sql .= 'IS NULL';
} else {
$param = 'where' . $i++;
$sql .= " = :$param";
$this->params[$param] = $value;
}
$this->where[] = $sql;
}
}