corona sdk insert row tableview - lua

Question

struggling with a problem! I need to insert in a tableview the outcome of a DB query. The problem is that i cannot insert data since when i do it the result is nil...If i try to insert fixed data (like a general string "hello") it works! Can someone help me? Thanks a lot.
function listatornei()
local dataURL = "http://www.lineitup.it/torneiopen.php?me="..usrUsr
numtornei=0
local function listaListener(event)
if event.phase=="ended" then
if (event.isError) then
print("Connection not available")
else
id_tor = {} -- array to store query field1
usr_tor = {} -- array to store query field2
local tab = event.response -- read json data
tab = json.decode( tab ) -- tabel conversion
if #tab > 0 then
for i=1, #tab do
id_tor[i] = tab[i]["idt"]
usr_tor[i] = tab[i]["gioc1_usr"]
numtornei=i
end
-- Listen for tableView events
local function tableViewListener( event )
local phase = event.phase
print( event.phase )
end
-- Handle row rendering
local function onRowRender( event )
local phase = event.phase
local row = event.row
local id = row.index
row.bg = display.newRect( 0, 0, display.contentWidth, 60 )
row.bg.anchorX = 0
row.bg.anchorY = 0
row.bg:setFillColor( 1, 1, 0 )
row:insert( row.bg )
row.idt = display.newText(id_tor[i], 0, 0, native.systemFontBold, 40 )
--row.idt = display.newText("pippo", 0, 0, native.systemFontBold, 40 )
row.idt.anchorX = 0
row.idt.anchorY = 0.5
row.idt:setFillColor( 0 )
row.idt.y = 20
row.idt.x = 42
row.usr = display.newText( usr_tor[i], 0, 0, native.systemFont, 40 )
--row.usr = display.newText( "pluto", 0, 0, native.systemFont, 40 )
row.usr.anchorX = 0
row.usr.anchorY = 0.5
row.usr:setFillColor( 0.5 )
row.usr.y = 20
row.usr.x = 250
row:insert( row.idt )
row:insert( row.usr )
end
-- Handle row's becoming visible on screen
local function onRowUpdate( event )
local row = event.row
print( "Row:", row.index, " is now visible" )
end
-- Handle touches on the row
local function onRowTouch( event )
local phase = event.phase
if "press" == phase then
print( "Touched row:", event.target.index )
end
end
-- Create a tableView
local tableView = widget.newTableView
{
top = 100,
width = 620,
height = 410,
--maskFile = "formlog1.png",
listener = tableViewListener,
onRowRender = onRowRender,
onRowTouch = onRowTouch,
}
for i = 1, numtornei do
local isCategory = false
local rowHeight = 60
local rowColor =
{
default = { 255, 255, 0 },
}
local lineColor = { 220, 220, 220 }
-- Make some rows categories
if i == 25 or i == 50 then
isCategory = true
rowHeight = 24
rowColor =
{
default = { 150, 160, 180, 200 },
}
end
-- Insert the row into the tableView
tableView:insertRow
{
isCategory = isCategory,
rowHeight = rowHeight,
rowColor = rowColor,
lineColor = lineColor,
}
end
end
end
end
end
network.request( dataURL, "GET", listaListener )
end

Answer 1

You need to check your data coming back from the database. If the data from the database is nil, don't insert it. In your onRowRender function, you should test each bit of data to make sure it's not nil before you try to use to create an object.
In addition, you have a potential scope problem as well. onRowRender() is driven by an event of a table row becoming visible on the screen. It is not called synchronously inside of the for loop. The loop with your inserts will likely complete before the first row's onRowRender() completes. You also referencing the variable "i" inside onRowRender() which will be nil later when the rows render. If you database rows will always be in a 1 to 1 relationship with your tableView rows (i.e. no category rows), then you can use the row ID to look up your data in your data tables. If not, you should use the form of passing in data when you insert the rows. See: https://coronalabs.com/blog/2014/03/04/tutorial-advanced-tableview-tactics/ and look at the Passable Parameters section.