fix: calculate chart data from beginning of period

- show period as label

frappe/desk/doctype/dashboard_chart/dashboard_chart.py

@@ -8,8 +8,7 @@ from frappe import _
 import datetime
 import json
 from frappe.utils.dashboard import cache_source, get_from_date_from_timespan
-from frappe.utils import nowdate, add_to_date, getdate, get_last_day, formatdate,\
-	get_datetime, cint, now_datetime
+from frappe.utils import *
 from frappe.model.naming import append_number_if_name_exists
 from frappe.boot import get_allowed_reports
 from frappe.model.document import Document
@@ -156,6 +155,7 @@ def add_chart_to_dashboard(args):
 def get_chart_config(chart, filters, timespan, timegrain, from_date, to_date):
 	if not from_date:
 		from_date = get_from_date_from_timespan(to_date, timespan)
+		from_date = get_period_beginning(from_date, timegrain)
 	if not to_date:
 		to_date = now_datetime()
 
@@ -163,7 +163,6 @@ def get_chart_config(chart, filters, timespan, timegrain, from_date, to_date):
 	datefield = chart.based_on
 	aggregate_function = get_aggregate_function(chart.chart_type)
 	value_field = chart.value_based_on or '1'
-	from_date = from_date.strftime('%Y-%m-%d')
 	to_date = to_date
 
 	filters.append([doctype, datefield, '>=', from_date, False])
@@ -185,7 +184,7 @@ def get_chart_config(chart, filters, timespan, timegrain, from_date, to_date):
 	result = get_result(data, timegrain, from_date, to_date)
 
 	chart_config = {
-		"labels": [formatdate(r[0].strftime('%Y-%m-%d')) for r in result],
+		"labels": [get_period(r[0], timegrain) for r in result],
 		"datasets": [{
 			"name": chart.name,
 			"values": [r[1] for r in result]
@@ -282,7 +281,7 @@ def get_result(data, timegrain, from_date, to_date):
 	start_date = getdate(from_date)
 	end_date = getdate(to_date)
 
-	result = [[start_date, 0.0]]
+	result = []
 
 	while start_date < end_date:
 		next_date = get_next_expected_date(start_date, timegrain)
@@ -304,6 +303,21 @@ def get_next_expected_date(date, timegrain):
 	next_date = get_period_ending(add_to_date(date, days=1), timegrain)
 	return getdate(next_date)
 
+def get_period_beginning(date, timegrain):
+	as_str = True
+	if timegrain == 'Daily':
+		pass
+	elif timegrain == 'Weekly':
+		date = get_first_day_of_week(date, as_str=as_str)
+	elif timegrain == 'Monthly':
+		date = get_first_day(date, as_str=as_str)
+	elif timegrain == 'Quarterly':
+		date = get_quarter_start(date, as_str=as_str)
+	elif timegrain == 'Yearly':
+		date = get_year_start(date, as_str=as_str)
+
+	return date
+
 def get_period_ending(date, timegrain):
 	date = getdate(date)
 	if timegrain == 'Daily':

frappe/utils/data.py

@@ -441,6 +441,17 @@ def get_timespan_date_range(timespan):
 
 	return date_range_map.get(timespan)
 
+def get_period(date, interval='Monthly'):
+	date = getdate(date)
+	months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
+	return {
+		'Daily': date.strftime('%d-%m-%y'),
+		'Weekly': date.strftime('%d-%m-%y'),
+		'Monthly': str(months[date.month - 1]) + ' ' + str(date.year),
+		'Quarterly': 'Quarter ' + str(((date.month-1)//3)+1) + ' ' + str(date.year),
+		'Yearly': str(date.year)
+	}[interval]
+
 def global_date_format(date, format="long"):
 	"""returns localized date in the form of January 1, 2012"""
 	date = getdate(date)