Note 14 - Loss Per Share - Weighted Average Number of Shares Used in the Calculation of the Basic and Diluted Loss Per Share (Details) - USD ($)	3 Months Ended						9 Months Ended
	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Apr. 30, 2020	Apr. 30, 2019
Net loss for the period	$ (3,273,644)	$ (1,888,661)	$ (5,042,577)	$ (5,017,557)	$ (2,349,674)	$ (3,451,426)	$ (10,204,882)	$ (10,818,657)
Basic Weighted Average Number of Shares (in shares)	183,896,944			179,648,614			182,637,673	174,213,254
Dilutive Stock Options, Warrants, RSUs and PRSUs (in shares)
Diluted Weighted Average Number of Shares (in shares)	183,896,944			179,648,614			182,637,673	174,213,254
NET LOSS PER SHARE, BASIC AND DILUTED (in dollars per share)	$ (0.02)			$ (0.03)			$ (0.06)	$ (0.06)