learnpress / inc / emails / class-lp-email.php

class-lp-email.php in LearnPress – WordPress LMS Plugin for Create and Sell Online Courses 4.1.7.3.1, at inc/emails/class-lp-email.php

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1	<?php
2	/**
3	* Class Email.
4	*
5	* @author ThimPress
6	* @category Widgets
7	* @package Learnpress/Email
8	* @since 3.0.0
9	* @version 3.0.2
10	*/
11
12	/**
13	* Prevent loading this file directly
14	*/
15	defined( 'ABSPATH' ) \|\| exit();
16
17	if ( ! class_exists( 'LP_Email' ) ) {
18
19	/**
20	* Class LP_Email
21	*/
22	class LP_Email extends LP_Abstract_Settings {
23	/**
24	* Email method ID.
25	*
26	* @var String
27	*/
28	public $id;
29
30	/**
31	* Email method title.
32	*
33	* @var string
34	*/
35	public $title;
36
37	/**
38	* 'yes' if the method is enabled.
39	*
40	* @var string
41	*/
42	public $enabled;
43
44	/**
45	* Description for the email.
46	*
47	* @var string
48	*/
49	public $description;
50
51	/**
52	* Plain text template path.
53	*
54	* @var string
55	*/
56	public $template_plain;
57
58	/**
59	* HTML template path.
60	*
61	* @var string
62	*/
63	public $template_html = '';
64
65	/**
66	* Template path.
67	*
68	* @var string
69	*/
70	public $template_base = '';
71
72	/**
73	* Recipients for the email.
74	*
75	* @var string
76	*/
77	public $recipient;
78
79	/**
80	* For display the field to setting specific emails.
81	* .
82	*
83	* @var string
84	*/
85	public $recipients = '';
86
87	/**
88	* Heading for the email content.
89	*
90	* @var string
91	*/
92	public $heading = '';
93
94	/**
95	* Subject for the email.
96	*
97	* @var string
98	*/
99	public $subject;
100
101	/**
102	* Default heading for the email content.
103	*
104	* @var string
105	*/
106	public $default_heading;
107
108	/**
109	* Default subject for the email.
110	*
111	* @var string
112	*/
113	public $default_subject;
114
115	/**
116	* Default content for the email.
117	*
118	* @var string
119	*/
120	public $content;
121
122	/**
123	* Object this email is for, for example a customer, product, or email.
124	*
125	* @var object
126	*/
127	public $object;
128
129	/**
130	* Strings to find in subjects/headings.
131	*
132	* @var array
133	*/
134	public $find;
135
136	/**
137	* Strings to replace in subjects/headings.
138	*
139	* @var array
140	*/
141	public $replace;
142
143	/**
144	* Mime boundary (for multipart emails).
145	*
146	* @var string
147	*/
148	public $mime_boundary;
149
150	/**
151	* Mime boundary header (for multipart emails).
152	*
153	* @var string
154	*/
155	public $mime_boundary_header;
156
157	/**
158	* True when email is being sent.
159	*
160	* @var bool
161	*/
162	public $sending;
163
164	public $debug = false;
165
166	protected $_object_loaded = false;
167
168	/**
169	* List of preg* regular expression patterns to search for,
170	* used in conjunction with $replace.
171	* https://raw.github.com/ushahidi/wp-silcc/master/class.html2text.inc
172	*
173	* @var array $search
174	* @see $replace
175	*/
176	public $plain_search = array(
177	"/\r/", // Non-legal carriage return
178	'/&(nbsp\|#160);/i', // Non-breaking space
179	'/&(quot\|rdquo\|ldquo\|#8220\|#8221\|#147\|#148);/i', // Double quotes
180	'/&(apos\|rsquo\|lsquo\|#8216\|#8217);/i', // Single quotes
181	'/>/i', // Greater-than
182	'/</i', // Less-than
183	'/&/i', // Ampersand
184	'/&/i', // Ampersand
185	'/&/i', // Ampersand
186	'/&(copy\|#169);/i', // Copyright
187	'/&(trade\|#8482\|#153);/i', // Trademark
188	'/&(reg\|#174);/i', // Registered
189	'/&(mdash\|#151\|#8212);/i', // mdash
190	'/&(ndash\|minus\|#8211\|#8722);/i', // ndash
191	'/&(bull\|#149\|#8226);/i', // Bullet
192	'/&(pound\|#163);/i', // Pound sign
193	'/&(euro\|#8364);/i', // Euro sign
194	'/$/', // Dollar sign
195	'/&[^&\s;]+;/i', // Unknown/unhandled entities
196	'/[ ]{2,}/', // Runs of spaces, post-handling
197	);
198
199	/**
200	* List of pattern replacements corresponding to patterns searched.
201	*
202	* @var array $replace
203	* @see $search
204	*/
205	public $plain_replace = array(
206	'', // Non-legal carriage return
207	' ', // Non-breaking space
208	'"', // Double quotes
209	"'", // Single quotes
210	'>', // Greater-than
211	'<', // Less-than
212	'&', // Ampersand
213	'&', // Ampersand
214	'&', // Ampersand
215	'(c)', // Copyright
216	'(tm)', // Trademark
217	'(R)', // Registered
218	'--', // mdash
219	'-', // ndash
220	'*', // Bullet
221	'�', // Pound sign
222	'EUR', // Euro sign. � ?
223	'$', // Dollar sign
224	'', // Unknown/unhandled entities
225	' ', // Runs of spaces, post-handling
226	);
227
228	/**
229	* List of pattern search corresponding to patterns replace.
230	*
231	* @var array text shortcode
232	*/
233	public $text_search = array();
234
235	/**
236	* List of pattern to replace
237	*
238	* @var array text replace
239	*/
240	public $text_replace = array();
241
242	/**
243	* Text message description
244	*
245	* @var string
246	*/
247	public $email_text_message_description = '';
248
249	/**
250	* @var string
251	*/
252	public $template_path = '';
253
254	/**
255	* @var null
256	*/
257	public $variables = array();
258
259	/**
260	* @var array\|null
261	*/
262	//public $basic_variables = array();
263
264	/**
265	* @var null
266	*/
267	public $general_variables = [];
268
269	/**
270	* @var null
271	*/
272	public $support_variables = [];
273
274	/**
275	* @var LP_Settings
276	*/
277	public $settings = null;
278
279	/**
280	* @var string
281	*/
282	public $email_format = 'html';
283
284	/**
285	* @var bool
286	*/
287	public $enable = false;
288
289	/**
290	* @var string
291	*/
292	public $group = '';
293
294	/**
295	* @var string
296	*/
297	protected $_option_id = '';
298
299	/**
300	* LP_Email constructor.
301	*/
302	public function __construct() {
303	// Set template base path to LP templates path if it is not set.
304	if ( empty( $this->template_base ) ) {
305	$this->template_base = LearnPress::instance()->plugin_path( 'templates/' );
306	}
307
308	/**
309	* Set template folder if it is not set. Default is 'learnpress'
310	*/
311	if ( empty( $this->template_path ) ) {
312	$this->template_path = learn_press_template_path();
313	}
314
315	if ( empty( $this->template_html ) ) {
316	$this->template_html = "emails/{$this->id}.php";
317	}
318
319	if ( empty( $this->template_plain ) ) {
320	$this->template_plain = "emails/plain/{$this->id}.php";
321	}
322
323	if ( ! $this->object ) {
324	$this->object = array();
325	}
326
327	$this->_option_id = 'emails_' . $this->id;
328
329	$this->settings = LP_Settings::instance()->get_group( $this->_option_id, '' );
330
331	/**
332	* Init general options
333	*/
334	$this->heading = $this->settings->get( 'heading', $this->default_heading );
335	$this->subject = $this->settings->get( 'subject', $this->default_subject );
336	$this->enable = $this->settings->get( 'enable', 'no' ) === 'yes';
337
338	if ( $this->settings->get( 'email_content.format' ) ) {
339	$this->email_format = ( $this->settings->get( 'email_content.format' ) == 'plain_text' ) ? 'plain' : 'html';
340	} else {
341	if ( LP_Settings::instance()->get( 'emails_general.default_email_content' ) ) {
342	$this->email_format = LP_Settings::instance()->get( 'emails_general.default_email_content' );
343	}
344	}
345
346	$email_formats = array( 'plain', 'html' );
347	if ( ! in_array( $this->email_format, $email_formats ) ) {
348	$this->email_format = 'html';
349	}
350
351	// Set type variables can click add to content of email setting.
352	$this->support_variables = $this->general_variables = [
353	'{{site_url}}',
354	'{{site_title}}',
355	'{{login_url}}',
356	'{{email_heading}}',
357	'{{site_admin_email}}',
358	'{{site_admin_name}}',
359	'{{header}}',
360	'{{footer}}',
361	'{{footer_text}}',
362	];
363	}
364
365	/**
366	* @param null $value
367	*
368	* @return bool
369	*/
370	public function enable( $value = null ): bool {
371	if ( is_bool( $value ) ) {
372	$this->enable = $value;
373
374	// Load default settings if the email is not configured
375	if ( ! $this->is_configured() ) {
376	$settings = $this->get_settings();
377
378	foreach ( $settings as $field ) {
379	if ( $field['type'] == 'heading' \|\| $field['type'] == 'title' \|\| $field['type'] == 'sectionend' ) {
380	continue;
381	}
382
383	$id = str_replace( $this->_option_id, '', $field['id'] );
384	$id = str_replace( array( '[', ']' ), '', $id );
385
386	if ( $id == 'email_content' ) {
387	$this->settings->set(
388	'email_content',
389	array(
390	'format' => 'html',
391	'plain' => lp_get_email_content( 'plain', '', $field ),
392	'html' => lp_get_email_content( 'html', '', $field ),
393	)
394	);
395	} else {
396	$this->settings->set( $id, $field['default'] );
397	}
398	}
399	}
400	$this->settings->set( 'enable', $value ? 'yes' : 'no' );
401	$this->settings->update( 'learn_press_' . $this->_option_id, $this->settings->get() );
402	}
403
404	return $this->enable;
405	}
406
407	/**
408	* @return mixed
409	*/
410	public function is_configured() {
411	return LP_Settings::instance()->get( $this->_option_id );
412	}
413
414	/**
415	* Get variables support in mail.
416	*
417	* @return mixed
418	*/
419	public function get_variables_support() {
420	return apply_filters( 'learn-press/email-variables-support', $this->support_variables, $this );
421	}
422
423	/**
424	* Magic function
425	*
426	* @param $key
427	*
428	* @return mixed
429	*/
430	public function __get( $key ) {
431	if ( ! empty( $this->{$key} ) ) {
432	return $this->{$key};
433	} else {
434	return $this->settings->get( $key );
435	}
436	}
437
438	/**
439	* @return bool
440	*/
441	private function is_current() {
442	return ! empty( $_REQUEST['section'] ) && sanitize_text_field( $_REQUEST['section'] ) == $this->id;
443	}
444
445	/**
446	* @param $options
447	* @param $key
448	*
449	* @return bool
450	*/
451	public function _remove_email_content_from_option( $options, $key ) {
452	if ( ! $this->is_current() ) {
453	return false;
454	}
455
456	if ( is_array( $options ) && ( array_key_exists( 'email_content_html', $options ) \|\| array_key_exists( 'email_content_plain', $options ) ) ) {
457
458	if ( array_key_exists( 'email_content_html', $options ) ) {
459	$this->save_template( $options['email_content_html'], $this->template_html );
460	unset( $options['email_content_html'] );
461	}
462
463	if ( array_key_exists( 'email_content_plain', $options ) ) {
464	$this->save_template( $options['email_content_plain'], $this->template_plain );
465	unset( $options['email_content_plain'] );
466	}
467	}
468
469	return $options;
470	}
471
472	/**
473	* Apply the value of variables for string
474	*
475	* @param string $string
476	*
477	* @return string
478	* @editor tungnx
479	*/
480	public function format_string( string $string ): string {
481	//$this->_maybe_get_object();
482
483	$search = $replace = array();
484	if ( is_array( $this->variables ) ) {
485	$search = array_keys( $this->variables );
486	$replace = array_values( $this->variables );
487	}
488	$search = apply_filters( 'learn-press/email-format-string-find', $search, $this );
489	$replace = apply_filters( 'learn-press/email-format-string-replace', $replace, $this );
490
491	return str_replace( $search, $replace, $string );
492	}
493
494	/**
495	* Get email recipient.
496	*
497	* @return string
498	*/
499	public function get_recipient() {
500	return apply_filters( 'learn-press/email-recipient-' . $this->id, $this->recipient, $this->object );
501	}
502
503	/**
504	* Get email subject.
505	*
506	* @return string
507	*/
508	public function get_subject(): string {
509	return $this->format_string( $this->subject );
510	}
511
512	/**
513	* Get email content.
514	*
515	* @return string
516	* @editor tungnx
517	*/
518	public function get_content(): string {
519	$email_format = $this->get_email_format();
520
521	if ( 'plain' == $email_format ) {
522	$email_content = preg_replace( $this->plain_search, $this->plain_replace, strip_tags( $this->get_content_plain() ) );
523	} elseif ( in_array( $email_format, array( 'html', 'multipart' ) ) ) {
524	$email_content = $this->get_content_html();
525	} else {
526	$email_content = preg_replace( $this->text_search, $this->text_replace, $this->get_content_text_message() );
527	}
528
529	$email_content = $this->format_string( $email_content );
530
531	return wordwrap( $email_content, 70 );
532	}
533
534	/**
535	* Get email heading.
536	*
537	* @return string
538	*/
539	public function get_heading(): string {
540	return $this->format_string( $this->heading );
541	}
542
543	/**
544	* Get email footer text.
545	*
546	* @return string
547	*/
548	public function get_footer_text(): string {
549	$text = LP_Settings::instance()->get( 'emails_general.footer_text', 'LearnPress' );
550
551	return LP_Helper::sanitize_params_submitted( $text, 'html' );
552	}
553
554	/**
555	* Get email content HTML.
556	*
557	* @return string
558	*/
559	public function get_content_html(): string {
560	$template = $this->get_template( 'template_html' );
561	$template_file = $this->template_base . $template;
562	$content = $this->settings->get( 'email_content.html', file_get_contents( $template_file ) );
563
564	return stripslashes( $content );
565	}
566
567	/**
568	* Get email content plain.
569	*
570	* @return string
571	*/
572	public function get_content_plain(): string {
573	$template = $this->get_template( 'template_plain' );
574	$template_file = $this->template_base . $template;
575	$content_tmp = LP_WP_Filesystem::instance()->file_get_contents( $template_file );
576	$content = $this->settings->get( 'email_content.plain', $content_tmp );
577	$content = stripslashes( $content );
578
579	return $content;
580	}
581
582	/**
583	* Get content context message.
584	*
585	* @return string
586	*/
587	public function get_content_text_message(): string {
588	return apply_filters( 'learn-press/email-text-message-' . $this->id, $this->settings->get( 'content_text_message' ) );
589	}
590
591	/**
592	* Get email headers.
593	*
594	* @return string\|array
595	*/
596	public function get_headers() {
597	return apply_filters( 'learn-press/email-headers', 'Content-Type: ' . $this->get_content_format() . "\r\n", $this->id, $this->object );
598	}
599
600	/**
601	* Get email attachments.
602	*
603	* @return array
604	*/
605	public function get_attachments() {
606	return apply_filters( 'learn-press/email-attachments', array(), $this->id, $this->object );
607	}
608
609	/**
610	* Get FROM address. Default is admin email.
611	*
612	* @return string
613	* @editor tungnx
614	* @version 1.0.1
615	* @editor tungnx
616	* @modify 4.1.4 - comment - not override hook
617	*/
618	/*public function get_from_address(): string {
619	$email = LP_Settings::instance()->get( 'emails_general.from_email', get_option( 'admin_email' ) );
620
621	return sanitize_email( $email );
622	}*/
623
624	/**
625	* Get FROM name. Default is Blog name.
626	*
627	* @return string
628	* @editor tungnx
629	* @version 1.0.1
630	*/
631	public function get_from_name(): string {
632	$name = LP_Settings::instance()->get( 'emails_general.from_name', get_option( 'blogname' ) );
633
634	return LP_Helper::sanitize_params_submitted( $name );
635	}
636
637	/**
638	* Get WP Blog name.
639	*
640	* @return string
641	*/
642	public function get_blogname() {
643	return wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES );
644	}
645
646	/**
647	* Get email content format.
648	*
649	* @return string
650	*/
651	public function get_content_format() {
652	switch ( $this->get_email_format() ) {
653	case 'text_message':
654	case 'html':
655	return 'text/html';
656	case 'multipart':
657	return 'multipart/alternative';
658	default:
659	return 'text/plain';
660	}
661	}
662
663	/**
664	* @return string
665	*/
666	public function get_email_format() {
667	return $this->email_format && class_exists( 'DOMDocument' ) ? $this->email_format : 'plain';
668	}
669
670	/**
671	* Apply css from external to inline.
672	*
673	* @param string $content
674	*
675	* @return string
676	*/
677	public function apply_style_inline( $content ) {
678	if ( in_array( $this->get_content_format(), array( 'text/html', 'multipart/alternative' ) ) && class_exists( 'DOMDocument' ) ) {
679
680	// get CSS styles
681	ob_start();
682	learn_press_get_template( 'emails/email-styles.php' );
683	$css = apply_filters( 'learn_press_email_styles', ob_get_clean(), $this->id, $this );
684
685	try {
686	if ( ! class_exists( 'Emogrifier' ) ) {
687	include_once LP_PLUGIN_PATH . 'inc/libraries/class-emogrifier.php';
688	}
689	// apply CSS styles inline for picky email clients
690	$emogrifier = new Emogrifier( $content, $css );
691	$content = $emogrifier->emogrify();
692
693	} catch ( Exception $e ) {
694
695	}
696	}
697
698	return apply_filters( 'learn-press/email-content-inline-style', $content, $this->id );
699	}
700
701	/**
702	* Get template file from type.
703	*
704	* @param string $type
705	*
706	* @return string
707	*/
708	public function get_template( $type ) {
709	$type = esc_attr( basename( $type ) );
710
711	if ( 'template_html' == $type ) {
712	return $this->template_html;
713	} elseif ( 'template_plain' == $type ) {
714	return $this->template_plain;
715	}
716
717	return '';
718	}
719
720	protected function save_template( $code, $path ) {
721	return;
722	}
723
724	/**
725	* Get template file.
726	*
727	* @param string $template
728	* @param string $template_path
729	*
730	* @return string
731	*/
732	public function get_theme_template_file( $template, $template_path = null ) {
733	$template_dir = apply_filters( 'learn-press/template-directory', $template_path ? $template_path : learn_press_template_path(), $template );
734
735	return join(
736	'',
737	array(
738	trailingslashit( get_stylesheet_directory() ),
739	trailingslashit( $template_dir ),
740	$template,
741	)
742	);
743	}
744
745	/**
746	* Send email.
747	*
748	* @param string\|array $to
749	* @param string $subject
750	* @param string $message
751	* @param string\|string[] $headers
752	* @param array $attachments
753	*
754	* @editor tungnx
755	* @version 1.0.1
756	*
757	* @return bool
758	*/
759	public function send( $to, string $subject, string $message, $headers, array $attachments ): bool {
760	$return = false;
761	$message = apply_filters( 'learn-press/email-content', $this->apply_style_inline( $message ), $this );
762
763	if ( is_string( $to ) ) {
764	$to = preg_split( '~\s?,\s?~', $to );
765
766	$return = wp_mail( $to, $subject, $message, $headers, $attachments );
767	} elseif ( is_array( $to ) ) {
768	foreach ( $to as $t ) {
769	$return = wp_mail( $t, $subject, $message, $headers, $attachments );
770	}
771	}
772
773	return $return;
774	}
775
776	/**
777	* Get all values set and send email
778	*
779	* @author tungnx
780	* @since 4.1.3
781	*/
782	public function send_email(): bool {
783	add_filter( 'wp_mail_from_name', array( $this, 'get_from_name' ) );
784	add_filter( 'wp_mail_content_type', array( $this, 'get_content_format' ) );
785
786	return $this->send( $this->get_recipient(), $this->get_subject(), $this->get_content(), $this->get_headers(), $this->get_attachments() );
787	}
788
789	/**
790	* Get common variables.
791	* Variables use for click add to content of Email
792	*
793	* @param string $format
794	* @return array
795	* @author tungnx
796	* @since 4.1.1
797	*/
798	public function get_common_variables( string $format = 'plain' ): array {
799	$heading = strip_tags( $this->get_heading() );
800	$footer_text = strip_tags( $this->get_footer_text() );
801
802	$header = $heading;
803	$footer = $footer_text;
804
805	if ( $format != 'plain' ) {
806	$header = $this->email_header( $heading, false );
807	$footer = $this->email_footer( $footer_text, false );
808	}
809
810	$admin_user = get_user_by( 'email', get_option( 'admin_email' ) );
811	return apply_filters(
812	'email_variables_common',
813	[
814	'{{header}}' => $header,
815	'{{footer}}' => $footer,
816	'{{footer_text}}' => $footer_text,
817	'{{site_url}}' => get_home_url(),
818	'{{site_title}}' => $this->get_blogname(),
819	'{{site_admin_email}}' => get_option( 'admin_email' ),
820	'{{site_admin_name}}' => learn_press_get_profile_display_name( $admin_user ),
821	'{{login_url}}' => learn_press_get_login_url(),
822	'{{plain_text}}' => $format == 'plain',
823	]
824	);
825	}
826
827	/**
828	* @param string $name
829	*
830	* @return string
831	*/
832	public function get_field_name( $name ) {
833	return $this->_option_id . "[$name]";
834	}
835
836	/**
837	* Default options for all emails.
838	* Almost the emails are the same with options.
839	*
840	* @return array
841	*/
842	protected function _default_settings(): array {
843	/**
844	* In case the email is not for sending to specific admin (like user who has bought course or author of course, etc..)
845	* So, we do not need this field.
846	*/
847
848	$enable_recipients = apply_filters( 'learn-press/enable-email-recipients', ! empty( $this->recipients ), $this );
849
850	$default = array_merge(
851	array(
852	array(
853	'type' => 'title',
854	),
855	array(
856	'title' => esc_html__( 'Enable/Disable', 'learnpress' ),
857	'type' => 'checkbox',
858	'default' => 'no',
859	'id' => $this->get_field_name( 'enable' ),
860	'desc' => $this->description,
861	),
862	),
863	$enable_recipients ? array(
864	array(
865	'title' => esc_html__( 'Recipient(s)', 'learnpress' ),
866	'type' => 'text',
867	'default' => get_option( 'admin_email' ),
868	'id' => $this->get_field_name( 'recipients' ),
869	'desc' => esc_html__( 'Separate other recipients with commas.', 'learnpress' ),
870	),
871	) : array(),
872	array(
873	array(
874	'title' => esc_html__( 'Subject', 'learnpress' ),
875	'type' => 'text',
876	'default' => $this->default_subject,
877	'id' => $this->get_field_name( 'subject' ),
878	'css' => 'width:400px',
879	),
880	array(
881	'title' => esc_html__( 'Email heading', 'learnpress' ),
882	'type' => 'text',
883	'default' => $this->default_heading,
884	'id' => $this->get_field_name( 'heading' ),
885	'css' => 'width:400px',
886	),
887	array(
888	'title' => esc_html__( 'Content type', 'learnpress' ),
889	'type' => 'email-content',
890	'default' => '',
891	'id' => $this->get_field_name( 'email_content' ),
892	'template_base' => $this->template_base,
893	'template_path' => $this->template_path,
894	'template_html' => $this->template_html,
895	'template_plain' => $this->template_plain,
896	'template_html_local' => $this->get_theme_template_file( 'html', $this->template_path ),
897	'template_plain_local' => $this->get_theme_template_file( 'plain', $this->template_path ),
898	'support_variables' => $this->get_variables_support(),
899	),
900	array(
901	'type' => 'sectionend',
902	),
903	)
904	);
905
906	return $default;
907	}
908
909	/**
910	* Get settings in admin.
911	*
912	* @since 3.0.0
913	*
914	* @return bool\|mixed
915	*/
916	public function get_settings() {
917	return apply_filters( 'learn-press/email-settings/' . $this->id . '/settings', $this->_default_settings() );
918	}
919
920	/**
921	* Get instructors to send mail.
922	*
923	* @since 3.0.0
924	*
925	* @param null $order_id
926	*
927	* @return array
928	*/
929	public function get_order_instructors( $order_id ) {
930	if ( ! $order_id ) {
931	return array();
932	}
933
934	$order = learn_press_get_order( $order_id );
935
936	$items = $order->get_items();
937	$instructors = array();
938
939	if ( count( $items ) ) {
940	foreach ( $items as $item ) {
941	if ( ! isset( $item['course_id'] ) ) {
942	continue;
943	}
944
945	$user_id = get_post_field( 'post_author', $item['course_id'] );
946	if ( $user_id ) {
947	$instructors[] = $user_id;
948	}
949	}
950	}
951
952	return $instructors;
953	}
954
955	protected function _get_admin_email() {
956	return apply_filters( 'learn-press/email/admin-email', get_option( 'admin_email' ) );
957	}
958
959	/**
960	* @return string
961	*/
962	public function __toString() {
963	return $this->title;
964	}
965
966	/**
967	* Get image header in general settings.
968	*
969	* @return string
970	*/
971	public function get_image_header(): string {
972	$image = LP_Settings::instance()->get( 'emails_general.header_image', '' );
973
974	if ( ! empty( $image ) ) {
975	$image = wp_get_attachment_image_url( $image, 'full' );
976	}
977
978	return $image;
979	}
980
981	/**
982	* Email header.
983	*
984	* @param string $heading
985	* @param bool $echo
986	*
987	* @return string
988	*/
989	public function email_header( string $heading, bool $echo = true ): string {
990	ob_start();
991	learn_press_get_template(
992	'emails/email-header.php',
993	[
994	'email_heading' => $heading,
995	'image_header' => $this->get_image_header(),
996	]
997	);
998	$header = ob_get_clean();
999
1000	if ( $echo ) {
1001	echo wp_kses_post( $header );
1002	}
1003
1004	return $header;
1005	}
1006
1007	/**
1008	* Email footer.
1009	*
1010	* @param string $footer_text
1011	* @param bool $echo
1012	*
1013	* @return string
1014	*/
1015	public function email_footer( string $footer_text, bool $echo = true ): string {
1016	ob_start();
1017	learn_press_get_template( 'emails/email-footer.php', array( 'footer_text' => $footer_text ) );
1018	$footer = ob_get_clean();
1019
1020	if ( $echo ) {
1021	echo wp_kses_post( $footer );
1022	}
1023
1024	return $footer;
1025	}
1026
1027	/**
1028	* Set receive email
1029	*
1030	* @param string $receive_email
1031	*/
1032	public function set_receive( string $receive_email ) {
1033	$this->recipient = $receive_email;
1034	}
1035
1036	/**
1037	* Method called by background on LP_Background_Single_Email
1038	* @see LP_Background_Single_Email::handle()
1039	*
1040	* @param array $params
1041	*/
1042	public function handle( array $params ) {
1043
1044	}
1045	}
1046	}
1047