7. Net Loss per Common Share (Details - Antidilutive shares, conversion price) - shares	12 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
RSUs [Member]
Dilutive effect of shares on diluted shares outstanding	34,122	0	0
If Converted Method [Member] | Stock Options [Member]
Dilutive effect of shares on diluted shares outstanding	2,712,454	3,636,699	4,156,421
If Converted Method [Member] | RSUs [Member]
Dilutive effect of shares on diluted shares outstanding	33,532	0	0
If Converted Method [Member] | Warrants
Dilutive effect of shares on diluted shares outstanding	12,942	39,040	39,040
If Converted Method [Member] | Series E Preferred Stock [Member]
Dilutive effect of shares on diluted shares outstanding	1,978,783	1,978,783	1,955,588
If Converted Method [Member] | Option, RSUs, Warrants, Series E Preferred Stock [Member]
Dilutive effect of shares on diluted shares outstanding	4,737,711	5,654,522	6,151,049