feat(Payroll): compute Year to Date for Salary Slip components
diff --git a/erpnext/payroll/doctype/salary_detail/salary_detail.json b/erpnext/payroll/doctype/salary_detail/salary_detail.json
index 5c1eb61..9bc25a6 100644
--- a/erpnext/payroll/doctype/salary_detail/salary_detail.json
+++ b/erpnext/payroll/doctype/salary_detail/salary_detail.json
@@ -9,6 +9,7 @@
   "abbr",
   "column_break_3",
   "amount",
+  "year_to_date",
   "section_break_5",
   "additional_salary",
   "statistical_component",
@@ -226,11 +227,19 @@
   {
    "fieldname": "column_break_24",
    "fieldtype": "Column Break"
+  },
+  {
+   "description": "Total amount spent on this salary component from the beginning of the year (payroll or fiscal) to the current payroll date.",
+   "fieldname": "year_to_date",
+   "fieldtype": "Currency",
+   "label": "Year To Date",
+   "options": "currency",
+   "read_only": 1
   }
  ],
  "istable": 1,
  "links": [],
- "modified": "2020-11-25 13:12:41.081106",
+ "modified": "2021-01-13 17:33:19.184195",
  "modified_by": "Administrator",
  "module": "Payroll",
  "name": "Salary Detail",
diff --git a/erpnext/payroll/doctype/salary_slip/salary_slip.js b/erpnext/payroll/doctype/salary_slip/salary_slip.js
index 51fb359..945bd45 100644
--- a/erpnext/payroll/doctype/salary_slip/salary_slip.js
+++ b/erpnext/payroll/doctype/salary_slip/salary_slip.js
@@ -138,11 +138,11 @@
 	},
 
 	change_grid_labels: function(frm) {
-		frm.set_currency_labels(["amount", "default_amount", "additional_amount", "tax_on_flexible_benefit",
-			"tax_on_additional_salary"], frm.doc.currency, "earnings");
+		let fields = ["amount", "year_to_date", "default_amount", "additional_amount", "tax_on_flexible_benefit",
+		"tax_on_additional_salary"];
 
-		frm.set_currency_labels(["amount", "default_amount", "additional_amount", "tax_on_flexible_benefit",
-			"tax_on_additional_salary"], frm.doc.currency, "deductions");
+		frm.set_currency_labels(fields, frm.doc.currency, "earnings");
+		frm.set_currency_labels(fields, frm.doc.currency, "deductions");
 	},
 
 	refresh: function(frm) {
diff --git a/erpnext/payroll/doctype/salary_slip/salary_slip.py b/erpnext/payroll/doctype/salary_slip/salary_slip.py
index 183ad13..2d3bc57 100644
--- a/erpnext/payroll/doctype/salary_slip/salary_slip.py
+++ b/erpnext/payroll/doctype/salary_slip/salary_slip.py
@@ -52,6 +52,7 @@
 		self.calculate_net_pay()
 		self.compute_year_to_date()
 		self.compute_month_to_date()
+		self.compute_component_wise_year_to_date()
 
 		if frappe.db.get_single_value("Payroll Settings", "max_working_hours_against_timesheet"):
 			max_working_hours = frappe.db.get_single_value("Payroll Settings", "max_working_hours_against_timesheet")
@@ -1138,16 +1139,7 @@
 
 	def compute_year_to_date(self):
 		year_to_date = 0
-		payroll_period = get_payroll_period(self.start_date, self.end_date, self.company)
-
-		if payroll_period:
-			period_start_date = payroll_period.start_date
-			period_end_date = payroll_period.end_date
-		else:
-			# get dates based on fiscal year if no payroll period exists
-			fiscal_year = get_fiscal_year(date=self.start_date, company=self.company, as_dict=1)
-			period_start_date = fiscal_year.year_start_date
-			period_end_date = fiscal_year.year_end_date
+		period_start_date, period_end_date = self.get_year_to_date_period()
 
 		salary_slip_sum = frappe.get_list('Salary Slip',
 			fields = ['sum(net_pay) as sum'],
@@ -1180,6 +1172,47 @@
 		month_to_date += self.net_pay
 		self.month_to_date = month_to_date
 
+	def compute_component_wise_year_to_date(self):
+		period_start_date, period_end_date = self.get_year_to_date_period()
+
+		for key in ('earnings', 'deductions'):
+			for component in self.get(key):
+				year_to_date = 0
+				component_sum = frappe.db.sql("""
+					SELECT sum(detail.amount) as sum
+					FROM `tabSalary Detail` as detail
+					INNER JOIN `tabSalary Slip` as salary_slip
+					ON detail.parent = salary_slip.name
+					WHERE
+						salary_slip.employee_name = %(employee_name)s
+						AND detail.salary_component = %(component)s
+						AND salary_slip.start_date >= %(period_start_date)s
+						AND salary_slip.end_date < %(period_end_date)s
+						AND salary_slip.name != %(docname)s
+						AND salary_slip.docstatus = 1""",
+						{'employee_name': self.employee_name, 'component': component.salary_component, 'period_start_date': period_start_date,
+							'period_end_date': period_end_date, 'docname': self.name}
+				)
+
+				year_to_date = flt(component_sum[0][0]) if component_sum else 0.0
+				year_to_date += component.amount
+				component.year_to_date = year_to_date
+
+	def get_year_to_date_period(self):
+		payroll_period = get_payroll_period(self.start_date, self.end_date, self.company)
+
+		if payroll_period:
+			period_start_date = payroll_period.start_date
+			period_end_date = payroll_period.end_date
+		else:
+			# get dates based on fiscal year if no payroll period exists
+			fiscal_year = get_fiscal_year(date=self.start_date, company=self.company, as_dict=1)
+			period_start_date = fiscal_year.year_start_date
+			period_end_date = fiscal_year.year_end_date
+
+		return period_start_date, period_end_date
+
+
 def unlink_ref_doc_from_salary_slip(ref_no):
 	linked_ss = frappe.db.sql_list("""select name from `tabSalary Slip`
 	where journal_entry=%s and docstatus < 2""", (ref_no))