Simple demo of tableview logic for the novices

polymerchm

# coding: utf-8
# and example of tableview and how to control/use them


import ui,console

def listShuffle(list,row_from, row_to):
	''' a method to re-order a list '''
	from_item = list[row_from]
	del list[row_from]
	list.insert(row_to,from_item)
	return list

class tvDelegate(object): #also acts as the data_source.  Can be separate, but this is easier.  
	def __init__(self,items):	
		self.items = items
		self.currentNumLines = len(items)
		self.currentTitle = None
		self.currentRow = None
		
	def tableview_did_select(self, tableview, section, row):
		# Called when a row was selected.
		try:
			self.items[self.currentRow]['accessory_type'] = 'none' # un-flags current selected row
		except TypeError: #needed for very first selection
			pass
		self.items[row]['accessory_type']  = 'checkmark'
		self.currentTitle = self.items[row]['title']
		self.currentRow = row # needed for the test above
		tableview.reload_data() # forces changes into the displayed list

		
	def tableview_did_deselect(self, tableview, section, row):
		# Called when a row was de-selected (in multiple selection mode).
		pass

	def tableview_title_for_delete_button(self, tableview, section, row):
		# Return the title for the 'swipe-to-***' button.
		return 'Delete' # or 'bye bye' or 'begone!!!'
		
	def tableview_number_of_sections(self, tableview):
		# Return the number of sections (defaults to 1). Someone else can mess with 
		# sections and section logic
		return 1

	def tableview_number_of_rows(self, tableview, section):
		# Return the number of rows in the section
		return self.currentNumLines #needed to be in sync with displayed version, 

	def tableview_cell_for_row(self, tableview, section, row):
		# Create and return a cell for the given section/row
		cell = ui.TableViewCell()
		cell.text_label.text =  self.items[row]['title']
		cell.accessory_type = self.items[row]['accessory_type']
		# or you could comment out the line above and use
		#
		#if self.items[row]['accessory_type'] == 'checkmark':
		#	cell.text_label.font = ('<system-bold>',20)
		# or 
		# cell.text_label.text_color = '#FF0000'
		#
		# for emphasis instead 
		#  
		return cell


	def tableview_can_delete(self, tableview, section, row):
		# Return True if the user should be able to delete the given row.
		return True # you can use logic to lock out specific ("pinned" entries) 

	def tableview_can_move(self, tableview, section, row):
		# Return True if a reordering control should be shown for the given row (in editing mode).
		return True # see above

	def tableview_delete(self, tableview, section, row):
		# Called when the user confirms deletion of the given row.
		self.currentNumLines -=1 # see above regarding hte "syncing"
		tableview.delete_rows((row,)) # this animates the deletion  could also 'tableview.reload_data()'
		del self.items[row]

	def tableview_move_row(self, tableview, from_section, from_row, to_section, to_row):
		# Called when the user moves a row with the reordering control (in editing mode).
		
		self.items = listShuffle(self.items,from_row,to_row) 
		# cynchronizes what is displayed with the underlying list

def onEdit(sender):
	global tv
	tv.editing = True

	
def onDone(sender):
	global tv
	tv.editing = False
	# to avoid consufion in the selection logic, I clear all accessory type after an edit.
	for row in range(len(tv.data_source.items)):
		tv.data_source.items[row]['accessory_type'] = 'none'
	tv.reload_data()

titles = "one two three four five six seven eight".split()
itemlist = [{'title': x, 'accessory_type':'none'} for x in titles]

vdel = tvDelegate(items=itemlist)

#the pyui file consists of a tableview named tv_1
#and two buttons named button1 and button2 with labels 'edit' and 'done' respectively


v = ui.load_view()
tv = v['tv_1']
v['button1'].action = onEdit
v['button2'].action = onDone
tv.delegate = tv.data_source = vdel
v.present('sheet')

Dalkey

Thank you. Most helpful and much appreciated. The try: in the tableview_did_select() is very elegant.

polymerchm

Very pythonic. Thanks.

polymerchm

Underlines are treated as markers for italicized words in markdown (the formatting language for this forum) To have the underlines show, use the triple backtick formalism to enclose code thusly _italics_

ccc

This is a bit overstated for non-production code but still an interesting perspective: The Most Diabolical Python Antipattern

omz

@polymerchm You can also use a single pair of backticks.

ccc

Suggestion: Add the expected error to except clause.

        try:
            self.items[self.currentRow]['accessory_type'] = 'none' # un-flags current selected row
        except TypeError: #needed for very first selection
            pass

hecate

I realize this was written quite a long time ago, but I tried to use the code in this example and I struggle to understand how I can have both multiple select and deselect.

By changing the row
self.currentRow = row # needed for the test above
to
self.currentRow = selected = tableview.selected_rows
I manage to get to the multi-select-part, not fancy nor smart, but from there I am currently at loss.

Anything someone could suggest?

enceladus

The following url has few examples and hope it helps.
https://github.com/encela95dus/ios_pythonista_examples

table_example1,2,3,4 - tableview examples
from forum
file navigation https://github.com/dgelessus/filenav/blob/master/litenav.py
fill rows based on the characters that are entered on textfield
https://forum.omz-software.com/topic/4328/modules-of-pythonista-displayed-with-help

hecate

That was a great resource for examples, thank you!
By multi-selection I mean that you can add and remove check-marks on several rows in the table, I couldn't that these examples adressed that... Or am I missing something?

enceladus

Do you need something like this? It uses dialog but table example would be similar to that.

import dialogs

def multiple_selection_list_dialog(lst):
    form_list_of_dicts = []
    for item in lst:
        form_list_of_dicts.append(dict(type = 'check', title = item,
            key = item, value = False))  
    result = dialogs.form_dialog(title = 'Multiple Selection List', fields=form_list_of_dicts) 
    return [i for i in result if result[i]] if result else None

if __name__ == '__main__':
    lst = ['a'+str(i) for i in range(5)]
    print(multiple_selection_list_dialog(lst))

hecate

Exactly! Lovely!

I will have to look into this in more detail but if I understand this correctly, return [i for i in result if result[i]] if result else None is what makes it possible to deselect?

I find it a bit confusing that in the table_view_source example http://omz-software.com/pythonista/docs/ios/ui.html#tableview there is a method called tableview_did_deselect but I couldn't see that it was ever being called..

Thank you kindly!

cvp

@hecate I agree, never seen did_deselect called...