added some validations

erpnext/crm/doctype/email_campaign/email_campaign.py

@@ -3,8 +3,26 @@
 # For license information, please see license.txt
 
 from __future__ import unicode_literals
-# import frappe
+import frappe
+from frappe import _
+from frappe.utils import getdate, add_days
 from frappe.model.document import Document
 
 class EmailCampaign(Document):
-	pass
+	def validate(self):
+		self.validate_dates()
+
+	def validate_dates(self):
+		campaign = frappe.get_doc("Campaign", self.campaign_name)
+
+		#email campaign cannot start before campaign
+		if campaign.from_date and getdate(self.start_date) < getdate(campaign.from_date):
+			frappe.throw(_("Email Campaign Start Date cannot be before Campaign Start Date"))
+
+		#check if email_schedule is exceeding the campaign end date
+		no_of_days = 0
+		for entry in self.get("email_schedule"):
+			no_of_days += entry.send_after_days
+		email_schedule_end_date = add_days(getdate(self.start_date), no_of_days)
+		if campaign.to_date and getdate(email_schedule_end_date) > getdate(campaign.to_date):
+			frappe.throw(_("Email Schedule cannot extend Campaign End Date"))