No court shall have jurisdiction to issue a temporary or permanent injunction in any case involving or growing out of a labor dispute, except after hearing the testimony of witnesses in open court, with opportunity for cross-examination, in support of the allegations of a complaint made under oath, and testimony in opposition thereto, if offered, and except after a finding of facts by the court, to the effect: (a) That unlawful acts have been threatened and will be committed by a person or persons unless such person or persons are restrained therefrom, but no injunction or temporary restraining order shall be issued on account of any threat or unlawful act except against the person or persons, association or organization making the threat or committing the unlawful act or actually authorizing or ratifying the same after actual knowledge thereof; (b) that substantial and irreparable injury to the complainant or his property will follow; (c) that as to each item of relief granted greater injury would be inflicted upon the complainant by the denial of relief than would be inflicted upon the defendants by the granting of relief; (d) that the complainant has no adequate remedy at law; and (e) that the public officers charged with the duty to protect the complainant’s property are unable or unwilling to furnish adequate protection. Such hearing shall be held after notice thereof has been given, in such manner as the court directs, to all known persons against whom relief is sought, provided, if a complainant also alleges that, unless a temporary restraining order is issued without notice, substantial and irreparable injury to the complainant or his property will be unavoidable, such a temporary restraining order may be issued upon testimony under oath, sufficient, if sustained, to justify the court in issuing a temporary injunction upon a hearing after notice. Such temporary restraining order shall be effective for no longer than three days and shall become void at the expiration of such three days, provided, if a hearing on a temporary injunction has begun before the expiration of such three days, the restraining order may, in the court’s discretion, be modified or continued until a decision is reached by said court. No temporary restraining order or temporary injunction shall be issued except on condition that the complainant shall first file an undertaking, with surety satisfactory to the court granting the injunction, to answer all damages in case the plaintiff in the action in which the injunction is applied for fails to prosecute the action to effect.