Clear text object from in Corona SDK - lua

I have a search feature in Corona SDK that displays results from my website. The first run works perfect but the second search results lay over top the old results.
txt_mybest get repeated and inserted in to a scroll view. I can figure out how to remove the previous results.
If I remove the scroll group it becomes unusable
local function sumbitConnented( event )
if ( event.isError ) then
local alert = native.showAlert( "Connection Error", "Your information was not sent.
Please check your connection" , { "OK" }, onComplete )
else
nyHeight = 35
local t_ninja = json.decode( event.response )
for key in pairs(t_ninja) do
local xxteam_name = t_ninja[key]["team_name"]
nyHeight = nyHeight + 60
txt_mybest = display.newText("Team: "..xxteam_name,0,0,native.systemFont,13)
txt_mybest.anchorX = 0
txt_mybest.x = 85
txt_mybest.y = 38 +nyHeight
txt_mybest:setTextColor( 20/255, 20/255, 20/255 )
scroll:insert(txt_mybest)
end
function onSearchRelease()
sendInfo = {["findTeam"] = findTeam.text}
local headers = {
["Content-Type"] = "application/json",
["Accept-Language"] = "en-US",
}
local params = {}
params.headers = headers
params.body = json.encode( sendInfo )
network.request( "http://www.website.com/team-search.php?f=hw&u_device="..muserID, "POST", sumbitConnented, params )
end
Hopefully "Bohemian" has the mental ability to comprehend this question

you can use txt_mybest.text= "your new text" .. this will change text for your display.newText object as long as the object exsits.

You can add a display group in your scroll view and add all the text in it. When you want to remove the results, simply remove the group and add another one into scroll view. Like that you won't risk destroying your Scroll View and your results would clear off easily.

Related

Sticky variable value in lua vim.keymap

I want to create a mapping in my neovim lua setup such that when I have a visual selection and hit <leader>ps, a telescope search is initiated with the selected text.
Here is what I have for the moment:
local builtin = require('telescope.builtin')
local function get_visual_selection()
local s_start = vim.fn.getpos("'<")
local s_end = vim.fn.getpos("'>")
local n_lines = math.abs(s_end[2] - s_start[2]) + 1
local lines = vim.api.nvim_buf_get_lines(0, s_start[2] - 1, s_end[2], false)
lines[1] = string.sub(lines[1], s_start[3], -1)
if n_lines == 1 then
lines[n_lines] = string.sub(lines[n_lines], 1, s_end[3] - s_start[3] + 1)
else
lines[n_lines] = string.sub(lines[n_lines], 1, s_end[3])
end
return table.concat(lines, '\n')
end
vim.keymap.set('n', '<leader>ps', function() -- works fine
builtin.grep_string({ search = vim.fn.input("Grep > ") });
end)
vim.keymap.set('v', '<leader>ps', function() -- gets the same first value for sel everytime!
local sel = get_visual_selection();
builtin.grep_string({ search = vim.fn.input("Grep > " .. sel) });
end)
This code works on the first time; but then the first text retrieved from selection never changes! I get the first text I selected over and over. I don't understand what is causing that. It seems the function gets hit by some sort of caching mechanism from lua...?
I finally used a different and simpler way of doing this exact thing using a remap, yank and paste; I still don't know what's wrong in my question's lua script though.
Here is the working lua map:
vim.keymap.set('v', '<leader>ps', 'y<leader>ps<C-r>*', { remap = true });

Re-initialize table without losing references

I'd like to re-initialize a table without losing references to it.
What I want to achieve is defining tables in files, and when a file is changed (with a text editor) the file is reloaded, changing the table. Of course this doesn't change the table but creates a new instance, old references will still point to the old table.
Any suggestions?
EDIT: I want to elaborate on what I want to achieve. An example with game characters and weapons. I want to modify the weapons.lua and so affect the characters.
-- weapons.lua
sword = { damage = 3 }
-- characters.lua
character = { weapon = sword }
Adding a level of indirection (putting "sword" inside "weapons") like suggested by JWT doesn't help, unless I split character into { weaponTable = weapons, weaponKey = "sword" } but I don't see this as an option.
Anchor everything that needs to survive in the global environment. Nesting is fine, and this doesn't have to be your primary reference. (You can still local things, but make sure to initialize those local variables from the global environment and update the global if you change the local.)
To initialize the global values, say
foo = foo or value -- if foo is always true-ish
bar = (bar == nil) and value or bar -- if bar may be `false`
To initialize or update tables, you can
foo = foo or { }
foo.bar = foo.bar or 23
foo.baz = foo.baz or 42
-- and so on...
but that's kinda icky, so maybe say
function reinit( new, old ) -- (re)initialize one level, prefer old
if old == nil then return new end
if type( old ) ~= "table" then return old end
for k, v in pairs( new ) do
if old[k] == nil then old[k] = v end
end
return old
end
function reset( new, old ) -- (re)initialize one level, prefer new
if old == nil then return new end
if type( old ) ~= "table" then return new end
for k, v in pairs( new ) do old[k] = v end
return old
end
and then just
foo = reinit( { bar = 23, baz = 42 }, foo ) -- only setting if not defined
-- or
foo = reset( { bar = 23, baz = 42 }, foo ) -- always overriding given fields
or maybe make it even more fancy and say
function traverse( t, path )
local here, last, lastk, created = t
-- follow path of several keys starting from t, creating tables as needed
for k in path:gmatch "[^.]+" do
k = tonumber( k ) or k -- convert all-number keys to integer (for arrays)
local next = here[k]
if not next then
next, created = { }, true
here[k] = next
else
created = false
end
lastk, last, here = k, here, next
end
return here, last, lastk, created
end
function repopulate( path, value, update )
update = update or reinit -- pass 'reset' as 'update' for the other behavior
-- or something entirely different if that's what you need
local here, last, lastk, created = traverse( _G, path )
if type( value ) == "table" then
update( value, here )
else
if created then last[lastk] = nil end -- created one level too much
update( { [lastk] = value }, last )
end
end
and then (with arbitrary nesting)
-- No need to create 'state' first if it doesn't exist yet!
-- (If it exists, it will get updated, otherwise it's created)
repopulate( "state.player.weapon", { kind = "sword", damage = 11 } )
-- Do keep in mind that generally update order is relevant -- you may want to
-- give a newly created player a default inventory, but you may not want to
-- "refill" the player's inventory on every reload. So generally `repopulate`
-- with the parent and all child nodes for from-scratch creation, then
-- `repopulate` the child nodes that need to be checked & potentially updated
-- as well.
-- (So here you'd probably repopulate `state.player` first and then
-- `state.player.weapon` or other fields only if they should be updated anyway.)
-- e.g.:
repopulate( "state.player", {
x = 0, y = 0, hp = 100, mp = 100, level = 0, -- and so on
weapon = { kind = "sword", damage = 11 }, -- etc. etc.
} )
-- on reload always force a sword-kind weapon, leave rest (damage, ...) as-is
repopulate( "state.player.weapon", { kind = "sword" }, reset )
-- or alternatively: only if player has no weapon, give them a sword
repopulate( "state.player.weapon", { kind = "sword", damage = 3 } )
And you can go further, add metamethods to hide some of that shuffling, define different update policies, ... – you've seen some of the possibilities, now go and build your own version that fits your style and your code.
(While you're free to use the above code in any way, please note that it was written ad-hoc in the browser. I did some testing, fixed some glitches, and it seems to work now, but don't be surprised if there's still one or two bugs hiding in there. So play with this, change it, break it (and see how/why it breaks), adapt and extend it, ... – but unless you completely understand what it does and can fix any bugs, I strongly suggest you write your own version, or just stick to the basics. You probably don't need everything that this does, and you're likely to need other things that this doesn't do. As this is a central part of the reloading/live-coding infrastructure and everything has to be adapted to be reload-compatible, any mismatch between your tooling and what you actually need will result in a lot of pain everywhere in your code. So if you need something like this, put in a day or two to make it work the way you need it to, or you will regret it.)
(Free bonus warning: If you do OOP, you'll probably have to store and retrieve your classes instead of creating them every time, otherwise old objects from previous iterations will miss code updates and still run their old methods. I've forgotten about that more than just a couple of times and wasted several hours pondering "why isn't it fixed now?!?" after repeatedly re-loading code... So remember to anchor your metatables, anchor your classes!)
You could nest the tables in another table.
Before:
local a = { 1, 2, 3 }
local b = { 7, 8, 9 }
print(a[2] + b[2]) -- #=> 10
After:
local lookup = {
a = { 1, 2, 3 },
b = { 7, 8, 9 }
}
print(lookup.a[2] + lookup.b[2]) -- #=> 10
Then you can fully replace (or just update) a table in the lookup table and any dependent statements will use that updated value:
lookup.a = { 100, 50, 0 }
print(lookup.a[2] + lookup.b[2]) -- #=> 58
I don't know if it's exactly what you needed (As an ID is necessary) but I hope it will fit your needs.
meta = {
tables = {},
__call = function(arg, t)
for k, v in pairs(t) do
arg[k] = v
end
end,
__bnot = function(arg)
return arg.__key
end,
__newindex = function(arg, key, val)
meta.tables[arg.__key][key] = val
end,
__index = function(arg, key)
return meta.tables[arg.__key][key]
end
}
function RefTable(arg)
local newtable = {}
if arg ~= nil then
newtable.__key = arg
setmetatable(newtable, meta)
if meta.tables[arg] == nil then
meta.tables[arg] = {}
end
else
error("RefTable can't have nil key")
end
return newtable
end
-- Using the RefTable
sword = RefTable("Sword")
sword({damage = 3})
sword.cooldown = 10
character = {sword = sword}
print("base", sword.damage, sword.cooldown)
print("embed", character.sword.damage, character.sword.cooldown)
sword = RefTable("Sword")
sword({damage = 8, cooldown = 50})
print("embed2", character.sword.damage, character.sword.cooldown)
print(sword.__key, sword.cooldown)
ref = RefTable("Sword")
ref.cooldown = 1000
print(sword.cooldown)

TableView is not registering any events Corona

I am attempting to create a list of items using the TableView widget in Corona. I followed their online examples and created the TableView. It appears on the screen and is scrollable, but no event is fired when I click a row, even though I set a listener for OnRowTouch.
local options_for_list_view = {
id = "list_view",
top = 0,
left = 0,
width = display.contentWidth,
height = display.contentHeight,
hideBackground = true,
hideScrollBar = true,
listener = on_table_touch,
onRowRender = onRowRender,
onRowTouch = on_row_touch, -- registering listener
}
list_view = widget.newTableView(options_for_list_view)
for key, value in pairs(trophy_list) do
local params =
{
name = key
}
list_view:insertRow
{
isCategory = false,
rowHeight = total_height * 0.1,
rowColor = rowColor,
lineColor = { 0, 0, 0 },
params = params
}
end
Here is the listener:
local function on_row_touch( event )
print("error")
end
Does anyone know what the issue could be?
You should define Your on_row_touch( event ) function BEFORE adding it to the options_for_list_view Table.
Objects in Lua are created in the same order as listed in sources. So, in Your case, You're just putting a nil into the onRowTouch event's listener place. And just after that creating a local function which was supposed to be an event listener :)
Some proper static analysis tool should help getting rid of this kind of errors...
Good luck ;)
Simplified version:
print(foo())
function foo()
return "some_value..."
end
Output:
lua: ./call_test.lua:1: attempt to call global 'foo' (a nil value)

Lua Insert table to table

Basic table, how they should be. But me need do it by function, how i can do that?
local mainMenu = {
caption = "Main Window",
description = "test window",
buttons = {
{ id = 1, value = "Info" },
{ id = 2, value = "Return" },
{ id = 3, value = "Ok" },
{ id = 4, value = "Cancel" }
},
popup = true
}
Table should be based on outside params, and code one table for each variable of options - not better way. I make a function for that, they should create basic options like caption or description and pop up, and insert values to buttons table (if option enabled - add button). But here the problem, they wont insert to tmp table, buttons table and their values for next options.
function createMenu()
tmp = {}
--buttons insert
if(config.info) then
table.insert(tmp, {buttons = {id = 1, value = "Info"}});
elseif(config.return) then
table.insert(tmp, {buttons = {id = 2, value = "Return"}});
end
--table main
table.insert(tmp, {
caption = "Main Window",
description = "test window",
popup = true
})
return tmp
end
How i can fixing them?
From looking at your createMenu function, two obvious problems stick out:
assigning to global tmp a new table every time createMenu is
called.
using the return keyword as a key in config.
One can be a problem if you use tmp somewhere else in your code outside the createMenu function. The obvious fix is to change it to:
local tmp = {}
For the second problem, you can use a lua keyword as a table key if you really want but you won't be able to use the . dot syntax to access this since Lua will parse this the wrong way. Instead, you need to change:
config.return
to
config["return"].
Edit: After reading your comment and checking the example table, it looks like only the button table is accessed by numerical index. In that case, you'll want to use table.insert only on button. If you want to create the table to have associative keys then you'll have to do something like this:
function createMenu()
local tmp =
{
--table main
caption = "Main Window",
description = "test window",
popup = true,
--button table
buttons = {}
}
--buttons insert
if config.info then
table.insert(tmp.buttons, {id = 1, value = "Info"});
elseif config['return'] then
table.insert(tmp.buttons, {id = 2, value = "Return"});
end
return tmp
end
This will produce the mainMenu table you're describing in your question.

how to "page" through the data in a Lua table used as a dictionary?

How would I code a function to iterate through one "pages" worth of data? Sample code would be ideal...
So say we image the size of a page is 5 items. If we had a lua table with 18 items it would need to print out:
Page 1: 1 to 5
Page 2: 6 to 10
Page 3: 11 to 15
Page 4: 16 to 18
So assume the data is something like:
local data = {}
data["dog"] = {1,2,3}
data["cat"] = {1,2,3}
data["mouse"] = {1,2,3}
data["pig"] = {1,2,3}
.
.
.
How would one code the function that would do the equivalent of this:
function printPage (myTable, pageSize, pageNum)
-- find items in "myTable"
end
So in fact I'm not even sure if a Lua table used as a dictionary can even do this? There is no specific ordering is there in such a table, so how would you be sure the order would be the same when you come back to print page 2?
The next function allows you to go through a table in an order (albeit an unpredictable one). For example:
data = { dog = "Ralf", cat = "Tiddles", fish = "Joey", tortoise = "Fred" }
function printPage(t, size, start)
local i = 0
local nextKey, nextVal = start
while i < size and nextKey ~= nil do
nextKey, nextVal = next(t, nextKey)
print(nextKey .. " = " .. nextVal)
i = i + 1
end
return nextKey
end
local nextPage = printPage(data, 2) -- Print the first page
printPage(data, 2, nextPage) -- Print the second page
I know this isn't quite in the form you were after, but I'm sure it can be adapted quite easily.
The next function returns the key after the one provided in the table, along with its value. When the end of the table is reached, it returns nil. If you provide nil as the second parameter, it returns the first key and value in the table. It's also documented in Corona, although it appears to be identical.

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