<?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/>.
namespace core_user;
use core_text;
/**
* Class for retrieving information about user fields that are needed for displaying user identity.
*
* @package core_user
*/
class fields {
/** @var string Prefix used to identify custom profile fields */
const PROFILE_FIELD_PREFIX = 'profile_field_';
/** @var string Regular expression used to match a field name against the prefix */
const PROFILE_FIELD_REGEX = '~^' . self::PROFILE_FIELD_PREFIX . '(.*)$~';
/** @var int All fields required to display user's identity, based on server configuration */
const PURPOSE_IDENTITY = 0;
/** @var int All fields required to display a user picture */
const PURPOSE_USERPIC = 1;
/** @var int All fields required for somebody's name */
const PURPOSE_NAME = 2;
/** @var int Field required by custom include list */
const CUSTOM_INCLUDE = 3;
/** @var \context|null Context in use */
protected $context;
/** @var bool True to allow custom user fields */
protected $allowcustom;
/** @var bool[] Array of purposes (from PURPOSE_xx to true/false) */
protected $purposes;
/** @var string[] List of extra fields to include */
protected $include;
/** @var string[] List of fields to exclude */
protected $exclude;
/** @var int Unique identifier for different queries generated in same request */
protected static $uniqueidentifier = 1;
/** @var array|null Associative array from field => array of purposes it was used for => true */
protected $fields = null;
/**
* Protected constructor - use one of the for_xx methods to create an object.
*
* @param int $purpose Initial purpose for object or -1 for none
*/
protected function __construct(int $purpose = -1) {
$this->purposes = [
self::PURPOSE_IDENTITY => false,
self::PURPOSE_USERPIC => false,
self::PURPOSE_NAME => false,
];
if ($purpose != -1) {
$this->purposes[$purpose] = true;
}
$this->include = [];
$this->exclude = [];
$this->context = null;
$this->allowcustom = true;
}
/**
* Constructs an empty user fields object to get arbitrary user fields.
*
* You can add fields to retrieve with the including() function.
*
* @return fields User fields object ready for use
*/
public static function empty(): fields {
return new fields();
}
/**
* Constructs a user fields object to get identity information for display.
*
* The function does all the required capability checks to see if the current user is allowed
* to see them in the specified context. You can pass context null to get all the fields without
* checking permissions.
*
* If the code can only handle fields in the main user table, and not custom profile fields,
* then set $allowcustom to false.
*
* Note: After constructing the object you can use the ->with_xx, ->including, and ->excluding
* functions to control the required fields in more detail. For example:
*
* $fields = fields::for_identity($context)->with_userpic()->excluding('email');
*
* @param \context|null $context Context; if supplied, includes only fields the current user should see
* @param bool $allowcustom If true, custom profile fields may be included
* @return fields User fields object ready for use
*/
public static function for_identity(?\context $context, bool $allowcustom = true): fields {
$fields = new fields(self::PURPOSE_IDENTITY);
$fields->context = $context;
$fields->allowcustom = $allowcustom;
return $fields;
}
/**
* Constructs a user fields object to get information required for displaying a user picture.
*
* Note: After constructing the object you can use the ->with_xx, ->including, and ->excluding
* functions to control the required fields in more detail. For example:
*
* $fields = fields::for_userpic()->with_name()->excluding('email');
*
* @return fields User fields object ready for use
*/
public static function for_userpic(): fields {
return new fields(self::PURPOSE_USERPIC);
}
/**
* Constructs a user fields object to get information required for displaying a user full name.
*
* Note: After constructing the object you can use the ->with_xx, ->including, and ->excluding
* functions to control the required fields in more detail. For example:
*
* $fields = fields::for_name()->with_userpic()->excluding('email');
*
* @return fields User fields object ready for use
*/
public static function for_name(): fields {
return new fields(self::PURPOSE_NAME);
}
/**
* On an existing fields object, adds the fields required for displaying user pictures.
*
* @return $this Same object for chaining function calls
*/
public function with_userpic(): fields {
$this->purposes[self::PURPOSE_USERPIC] = true;
return $this;
}
/**
* On an existing fields object, adds the fields required for displaying user full names.
*
* @return $this Same object for chaining function calls
*/
public function with_name(): fields {
$this->purposes[self::PURPOSE_NAME] = true;
return $this;
}
/**
* On an existing fields object, adds the fields required for displaying user identity.
*
* The function does all the required capability checks to see if the current user is allowed
* to see them in the specified context. You can pass context null to get all the fields without
* checking permissions.
*
* If the code can only handle fields in the main user table, and not custom profile fields,
* then set $allowcustom to false.
*
* @param \context|null Context; if supplied, includes only fields the current user should see
* @param bool $allowcustom If true, custom profile fields may be included
* @return $this Same object for chaining function calls
*/
public function with_identity(?\context $context, bool $allowcustom = true): fields {
$this->context = $context;
$this->allowcustom = $allowcustom;
$this->purposes[self::PURPOSE_IDENTITY] = true;
return $this;
}
/**
* On an existing fields object, adds extra fields to be retrieved. You can specify either
* fields from the user table e.g. 'email', or profile fields e.g. 'profile_field_height'.
*
* @param string ...$include One or more fields to add
* @return $this Same object for chaining function calls
*/
public function including(string ...$include): fields {
$this->include = array_merge($this->include, $include);
return $this;
}
/**
* On an existing fields object, excludes fields from retrieval. You can specify either
* fields from the user table e.g. 'email', or profile fields e.g. 'profile_field_height'.
*
* This is useful when constructing queries where your query already explicitly references
* certain fields, so you don't want to retrieve them twice.
*
* @param string ...$exclude One or more fields to exclude
* @return $this Same object for chaining function calls
*/
public function excluding(...$exclude): fields {
$this->exclude = array_merge($this->exclude, $exclude);
return $this;
}
/**
* Gets an array of all fields that are required for the specified purposes, also taking
* into account the $includes and $excludes settings.
*
* The results may include basic field names (columns from the 'user' database table) and,
* unless turned off, custom profile field names in the format 'profile_field_myfield'.
*
* You should not rely on the order of fields, with one exception: if there is an id field
* it will be returned first. This is in case it is used with get_records calls.
*
* The $limitpurposes parameter is useful if you want to get a different set of fields than the
* purposes in the constructor. For example, if you want to get SQL for identity + user picture
* fields, but you then want to only get the identity fields as a list. (You can only specify
* purposes that were also passed to the constructor i.e. it can only be used to restrict the
* list, not add to it.)
*
* @param array $limitpurposes If specified, gets fields only for these purposes
* @return string[] Array of required fields
* @throws \coding_exception If any unknown purpose is listed
*/
public function get_required_fields(array $limitpurposes = []): array {
// The first time this is called, actually work out the list. There is no way to 'un-cache'
// it, but these objects are designed to be short-lived so it doesn't need one.
if ($this->fields === null) {
// Add all the fields as array keys so that there are no duplicates.
$this->fields = [];
if ($this->purposes[self::PURPOSE_IDENTITY]) {
foreach (self::get_identity_fields($this->context, $this->allowcustom) as $field) {
$this->fields[$field] = [self::PURPOSE_IDENTITY => true];
}
}
if ($this->purposes[self::PURPOSE_USERPIC]) {
foreach (self::get_picture_fields() as $field) {
if (!array_key_exists($field, $this->fields)) {
$this->fields[$field] = [];
}
$this->fields[$field][self::PURPOSE_USERPIC] = true;
}
}
if ($this->purposes[self::PURPOSE_NAME]) {
foreach (self::get_name_fields() as $field) {
if (!array_key_exists($field, $this->fields)) {
$this->fields[$field] = [];
}
$this->fields[$field][self::PURPOSE_NAME] = true;
}
}
foreach ($this->include as $field) {
if ($this->allowcustom || !preg_match(self::PROFILE_FIELD_REGEX, $field)) {
if (!array_key_exists($field, $this->fields)) {
$this->fields[$field] = [];
}
$this->fields[$field][self::CUSTOM_INCLUDE] = true;
}
}
foreach ($this->exclude as $field) {
unset($this->fields[$field]);
}
// If the id field is included, make sure it's first in the list.
if (array_key_exists('id', $this->fields)) {
$newfields = ['id' => $this->fields['id']];
foreach ($this->fields as $field => $purposes) {
if ($field !== 'id') {
$newfields[$field] = $purposes;
}
}
$this->fields = $newfields;
}
}
if ($limitpurposes) {
// Check the value was legitimate.
foreach ($limitpurposes as $purpose) {
if ($purpose != self::CUSTOM_INCLUDE && empty($this->purposes[$purpose])) {
throw new \coding_exception('$limitpurposes can only include purposes defined in object');
}
}
// Filter the fields to include only those matching the purposes.
$result = [];
foreach ($this->fields as $key => $purposes) {
foreach ($limitpurposes as $purpose) {
if (array_key_exists($purpose, $purposes)) {
$result[] = $key;
break;
}
}
}
return $result;
} else {
return array_keys($this->fields);
}
}
/**
* Gets fields required for user pictures.
*
* The results include only basic field names (columns from the 'user' database table).
*
* @return string[] All fields required for user pictures
*/
public static function get_picture_fields(): array {
return ['id', 'picture', 'firstname', 'lastname', 'firstnamephonetic', 'lastnamephonetic',
'middlename', 'alternatename', 'imagealt', 'email'];
}
/**
* Gets fields required for user names.
*
* The results include only basic field names (columns from the 'user' database table).
*
* Fields are usually returned in a specific order, which the fullname() function depends on.
* If you specify 'true' to the $strangeorder flag, then the firstname and lastname fields
* are moved to the front; this is useful in a few places in existing code. New code should
* avoid requiring a particular order.
*
* @param bool $differentorder In a few places, a different order of fields is required
* @return string[] All fields used to display user names
*/
public static function get_name_fields(bool $differentorder = false): array {
$fields = ['firstnamephonetic', 'lastnamephonetic', 'middlename', 'alternatename',
'firstname', 'lastname'];
if ($differentorder) {
return array_merge(array_slice($fields, -2), array_slice($fields, 0, -2));
} else {
return $fields;
}
}
/**
* Gets all fields required for user identity. These fields should be included in tables
* showing lists of users (in addition to the user's name which is included as standard).
*
* The results include basic field names (columns from the 'user' database table) and, unless
* turned off, custom profile field names in the format 'profile_field_myfield', note these
* fields will always be returned lower cased to match how they are returned by the DML library.
*
* This function does all the required capability checks to see if the current user is allowed
* to see them in the specified context. You can pass context null to get all the fields
* without checking permissions.
*
* @param \context|null $context Context; if not supplied, all fields will be included without checks
* @param bool $allowcustom If true, custom profile fields will be included
* @return string[] Array of required fields
* @throws \coding_exception
*/
public static function get_identity_fields(?\context $context, bool $allowcustom = true): array {
global $CFG;
// Only users with permission get the extra fields.
if ($context && !has_capability('moodle/site:viewuseridentity', $context)) {
return [];
}
// Split showuseridentity on comma (filter needed in case the showuseridentity is empty).
$extra = array_filter(explode(',', $CFG->showuseridentity));
// If there are any custom fields, remove them if necessary (either if allowcustom is false,
// or if the user doesn't have access to see them).
foreach ($extra as $key => $field) {
if (preg_match(self::PROFILE_FIELD_REGEX, $field, $matches)) {
$allowed = false;
if ($allowcustom) {
require_once($CFG->dirroot . '/user/profile/lib.php');
// Ensure the field exists (it may have been deleted since user identity was configured).
$field = profile_get_custom_field_data_by_shortname($matches[1], false);
if ($field !== null) {
$fieldinstance = profile_get_user_field($field->datatype, $field->id, 0, $field);
$allowed = $fieldinstance->is_visible($context);
}
}
if (!$allowed) {
unset($extra[$key]);
}
}
}
// For standard user fields, access is controlled by the hiddenuserfields option and
// some different capabilities. Check and remove these if the user can't access them.
$hiddenfields = array_filter(explode(',', $CFG->hiddenuserfields));
$hiddenidentifiers = array_intersect($extra, $hiddenfields);
if ($hiddenidentifiers) {
if (!$context) {
$canviewhiddenuserfields = true;
} else if ($context->get_course_context(false)) {
// We are somewhere inside a course.
$canviewhiddenuserfields = has_capability('moodle/course:viewhiddenuserfields', $context);
} else {
// We are not inside a course.
$canviewhiddenuserfields = has_capability('moodle/user:viewhiddendetails', $context);
}
if (!$canviewhiddenuserfields) {
// Remove hidden identifiers from the list.
$extra = array_diff($extra, $hiddenidentifiers);
}
}
// Re-index the entries and return.
$extra = array_values($extra);
return array_map([core_text::class, 'strtolower'], $extra);
}
/**
* Gets SQL that can be used in a query to get the necessary fields.
*
* The result of this function is an object with fields 'selects', 'joins', 'params', and
* 'mappings'.
*
* If not empty, the list of selects will begin with a comma and the list of joins will begin
* and end with a space. You can include the result in your existing query like this:
*
* SELECT (your existing fields)
* $selects
* FROM {user} u
* JOIN (your existing joins)
* $joins
*
* When there are no custom fields then the 'joins' result will always be an empty string, and
* 'params' will be an empty array.
*
* The $fieldmappings value is often not needed. It is an associative array from each field
* name to an SQL expression for the value of that field, e.g.:
* 'profile_field_frog' => 'uf1d_3.data'
* 'city' => 'u.city'
* This is helpful if you want to use the profile fields in a WHERE clause, becuase you can't
* refer to the aliases used in the SELECT list there.
*
* The leading comma is included because this makes it work in the pattern above even if there
* are no fields from the get_sql() data (which can happen if doing identity fields and none
* are selected). If you want the result without a leading comma, set $leadingcomma to false.
*
* If the 'id' field is included then it will always be first in the list. Otherwise, you
* should not rely on the field order.
*
* For identity fields, the function does all the required capability checks to see if the
* current user is allowed to see them in the specified context. You can pass context null
* to get all the fields without checking permissions.
*
* If your code for any reason cannot cope with custom fields then you can turn them off.
*
* You can have either named or ? params. If you use named params, they are of the form
* uf1s_2; the first number increments in each call using a static variable in this class and
* the second number refers to the field being queried. A similar pattern is used to make
* join aliases unique.
*
* If your query refers to the user table by an alias e.g. 'u' then specify this in the $alias
* parameter; otherwise it will use {user} (if there are any joins for custom profile fields)
* or simply refer to the field by name only (if there aren't).
*
* If you need to use a prefix on the field names (for example in case they might coincide with
* existing result columns from your query, or if you want a convenient way to split out all
* the user data into a separate object) then you can specify one here. For example, if you
* include name fields and the prefix is 'u_' then the results will include 'u_firstname'.
*
* If you don't want to prefix all the field names but only change the id field name, use
* the $renameid parameter. (When you use this parameter, it takes precedence over any prefix;
* the id field will not be prefixed, while all others will.)
*
* @param string $alias Optional (but recommended) alias for user table in query, e.g. 'u'
* @param bool $namedparams If true, uses named :parameters instead of indexed ? parameters
* @param string $prefix Optional prefix for all field names in result, e.g. 'u_'
* @param string $renameid Renames the 'id' field if specified, e.g. 'userid'
* @param bool $leadingcomma If true the 'selects' list will start with a comma
* @return \stdClass Object with necessary SQL components
*/
public function get_sql(string $alias = '', bool $namedparams = false, string $prefix = '',
string $renameid = '', bool $leadingcomma = true): \stdClass {
global $DB;
$fields = $this->get_required_fields();
$selects = '';
$joins = '';
$params = [];
$mappings = [];
$unique = self::$uniqueidentifier++;
$fieldcount = 0;
if ($alias) {
$usertable = $alias . '.';
} else {
// If there is no alias, we still need to use {user} to identify the table when there
// are joins with other tables. When there are no customfields then there are no joins
// so we can refer to the fields by name alone.
$gotcustomfields = false;
foreach ($fields as $field) {
if (preg_match(self::PROFILE_FIELD_REGEX, $field, $matches)) {
$gotcustomfields = true;
break;
}
}
if ($gotcustomfields) {
$usertable = '{user}.';
} else {
$usertable = '';
}
}
foreach ($fields as $field) {
if (preg_match(self::PROFILE_FIELD_REGEX, $field, $matches)) {
// Custom profile field.
$shortname = $matches[1];
$fieldcount++;
$fieldalias = 'uf' . $unique . 'f_' . $fieldcount;
$dataalias = 'uf' . $unique . 'd_' . $fieldcount;
if ($namedparams) {
$withoutcolon = 'uf' . $unique . 's' . $fieldcount;
$placeholder = ':' . $withoutcolon;
$params[$withoutcolon] = $shortname;
} else {
$placeholder = '?';
$params[] = $shortname;
}
$joins .= " JOIN {user_info_field} $fieldalias ON " .
$DB->sql_equal($fieldalias . '.shortname', $placeholder, false) . "
LEFT JOIN {user_info_data} $dataalias ON $dataalias.fieldid = $fieldalias.id
AND $dataalias.userid = {$usertable}id";
// For Oracle we need to convert the field into a usable format.
$fieldsql = $DB->sql_compare_text($dataalias . '.data', 255);
$selects .= ", $fieldsql AS $prefix$field";
$mappings[$field] = $fieldsql;
} else {
// Standard user table field.
$selects .= ", $usertable$field";
if ($field === 'id' && $renameid && $renameid !== 'id') {
$selects .= " AS $renameid";
} else if ($prefix) {
$selects .= " AS $prefix$field";
}
$mappings[$field] = "$usertable$field";
}
}
// Add a space to the end of the joins list; this means it can be appended directly into
// any existing query without worrying about whether the developer has remembered to add
// whitespace after it.
if ($joins) {
$joins .= ' ';
}
// Optionally remove the leading comma.
if (!$leadingcomma) {
$selects = ltrim($selects, ' ,');
}
return (object)['selects' => $selects, 'joins' => $joins, 'params' => $params,
'mappings' => $mappings];
}
/**
* Similar to {@see \moodle_database::sql_fullname} except it returns all user name fields as defined by site config, in a
* single select statement suitable for inclusion in a query/filter for a users fullname, e.g.
*
* [$select, $params] = fields::get_sql_fullname('u');
* $users = $DB->get_records_sql_menu("SELECT u.id, {$select} FROM {user} u", $params);
*
* @param string|null $tablealias User table alias, if set elsewhere in the query, null if not required
* @param bool $override If true then the alternativefullnameformat format rather than fullnamedisplay format will be used
* @return array SQL select snippet and parameters
*/
public static function get_sql_fullname(?string $tablealias = 'u', bool $override = false): array {
global $DB;
$unique = self::$uniqueidentifier++;
$namefields = self::get_name_fields();
// Create a dummy user object containing all name fields.
$dummyuser = (object) array_combine($namefields, $namefields);
$dummyfullname = fullname($dummyuser, $override);
// Extract any name fields from the fullname format in the order that they appear.
$matchednames = array_values(order_in_string($namefields, $dummyfullname));
$namelookup = $namepattern = $elements = $params = [];
foreach ($namefields as $index => $namefield) {
$namefieldwithalias = $tablealias ? "{$tablealias}.{$namefield}" : $namefield;
// Coalesce the name fields to ensure we don't return null.
$emptyparam = "uf{$unique}ep_{$index}";
$namelookup[$namefield] = "COALESCE({$namefieldwithalias}, :{$emptyparam})";
$params[$emptyparam] = '';
$namepattern[] = '\b' . preg_quote($namefield) . '\b';
}
// Grab any content between the name fields, inserting them after each name field.
$chunks = preg_split('/(' . implode('|', $namepattern) . ')/', $dummyfullname);
foreach ($chunks as $index => $chunk) {
if ($index > 0) {
$elements[] = $namelookup[$matchednames[$index - 1]];
}
if (core_text::strlen($chunk) > 0) {
// If content is just whitespace, add to elements directly (also Oracle doesn't support passing ' ' as param).
if (preg_match('/^\s+$/', $chunk)) {
$elements[] = "'$chunk'";
} else {
$elementparam = "uf{$unique}fp_{$index}";
$elements[] = ":{$elementparam}";
$params[$elementparam] = $chunk;
}
}
}
return [$DB->sql_concat(...$elements), $params];
}
/**
* Gets the display name of a given user field.
*
* Supports field names from the 'user' database table, and custom profile fields supplied in
* the format 'profile_field_xx'.
*
* @param string $field Field name in database
* @return string Field name for display to user
* @throws \coding_exception
*/
public static function get_display_name(string $field): string {
global $CFG;
// Custom fields have special handling.
if (preg_match(self::PROFILE_FIELD_REGEX, $field, $matches)) {
require_once($CFG->dirroot . '/user/profile/lib.php');
$fieldinfo = profile_get_custom_field_data_by_shortname($matches[1], false);
// Use format_string so it can be translated with multilang filter if necessary.
return $fieldinfo ? format_string($fieldinfo->name) : $field;
}
// Some fields have language strings which are not the same as field name.
switch ($field) {
case 'picture' : {
return get_string('pictureofuser');
}
}
// Otherwise just use the same lang string.
return get_string($field);
}
/**
* Resets the unique identifier used to ensure that multiple SQL fragments generated in the
* same request will have different identifiers for parameters and table aliases.
*
* This is intended only for use in unit testing.
*/
public static function reset_unique_identifier() {
self::$uniqueidentifier = 1;
}
/**
* Checks if a field name looks like a custom profile field i.e. it begins with profile_field_
* (does not check if that profile field actually exists).
*
* @param string $fieldname Field name
* @return string Empty string if not a profile field, or profile field name (without profile_field_)
*/
public static function match_custom_field(string $fieldname): string {
if (preg_match(self::PROFILE_FIELD_REGEX, $fieldname, $matches)) {
return $matches[1];
} else {
return '';
}
}
}