Advice with tables in lua

[Master_11]

Hi everyone,

I am facing a small problem with tables, well I am not sure how to add something to a table by using addCommandHandler.

 

Like, if this is my table

local random = {
	  --  x   =   y
		['a'] = 'Two',
  		['b'] = 'One',
  		['c'] = 'Ten',
}

Then how can I add another line to this table by a command (addCommandHandler)

For example

If the command is "/add Q A"  ~~~ ("/add d six")

then it should add a new line to the table like ->

local random = {
  
		['a'] = 'Two',
  		['b'] = 'One',
  		['c'] = 'Ten',
  		['d'] = 'Six',
}

On the other hand, I have something like this in my mind for the command:

local random = {
	  --  x   =   y
		['a'] = 'Two',
  		['b'] = 'One',
  		['c'] = 'Ten',
  		['d'] = 'Six',
}


function addabcdtotable(client, commandName, x, y)
	if (blabla ~= "18") then return false end
		if (x) then return false end --(Checks if (['d'] = 'Six',) already exists, if yes then it will simply return {where x = column and y = column-2})
    	Add-> (x,y)	--(This will add {['d'] = 'Six',} to the table)
end
addCommandHandler("add", addabcdtotable)


--For removing a line from table ->


function removeabcdfromtable(client, commandName, x, y)
	if (blabla ~= "18") then return false end
		if (x) then --(Checks if (['d'] = 'Six',) already exists, if yes then it will be removed from the table {where x = column-1 and y = column-2)
			Remove-> (x, y) --(This will remove the whole line and fix the gap ['d'] = 'Six',)
    	else
    		return false end
	end
end
addCommandHandler("rem", removeabcdfromtable)

-- NOW VERY IMPORTANT THE D IS ONLY THE EXAMPLE IT CAN BE ANYTHING LIKE (['ab'] = 'CD',) etc.. {X and Y is not the position please...}

 

[Bonsai]

Not exactly sure what you mean but adding and removing works like this:

--add
table['a'] = "abc"

--remove
table['a'] = nil

--check
if table['a'] then

 

[Master_11]

Not working, I tried it

You must use something to check the table name in which you want to add the line.

[IIYAMA]

I wouldn't say that so quickly. To me his example looks valid.

 

/add d six

random[x] = y

(or overwrite, `set` would be a better command based on it's functionality)

 

---

 

/rem d

if random[x] then
	random[x] = nil
end

 

[Master_11]

My Sincere apology, I got confused! and thanks! it is working well and fine, but If I may ask, is it possible to show the existing table into a GUI?

[Master_MTA]

4 hours ago, Master_11 said:

into a GUI

sure you can by using loop

for example:

---------------define table
local ta={}


---------------add Values to table
addCommandHandler('insert',function(cmd,key,value)
    if key~=nil and value~=nil then
      ta[key]=value
    end
    end)

--------------get all table values and keys
local text=''
for k,v in pairs(ta)do
	text=text..'['..k..']='..v..','
end

 

[Master_11]

I successfully converted it into a GUI, now the problem I face is that when I restart the script the stuff added to the table by the GUI gets removed from the table. how can I solve that, like something which can save the table after every 24 hours or something?

[IIYAMA]

How about xml?

https://wiki.multitheftauto.com/wiki/XML

[Master_MTA]

or

sql

[Master_11]

Didn't really got what you guys meant, can you give me a small example?

[IIYAMA]

There are already examples on the wiki:

 

-- Creates a file named "new.xml" with root node "newroot" and childnode "newchild".
function createFileHandler()
   local rootNode = xmlCreateFile("new.xml","newroot")
   local childNode = xmlCreateChild(rootNode, "newchild")
   xmlSaveFile(rootNode)
   xmlUnloadFile(rootNode)
end

addCommandHandler("createfile", createFileHandler)

example by Shadowstep07052

 

It shows you how to create a xml file, which has a new child.

 

 

https://wiki.multitheftauto.com/wiki/XmlCreateFile

 

XML syntax:

https://www.tutorialspoint.com/xml/xml_syntax.htm

[ShayF2]

8 hours ago, IIYAMA said:

There are already examples on the wiki:

 

-- Creates a file named "new.xml" with root node "newroot" and childnode "newchild".
function createFileHandler()
   local rootNode = xmlCreateFile("new.xml","newroot")
   local childNode = xmlCreateChild(rootNode, "newchild")
   xmlSaveFile(rootNode)
   xmlUnloadFile(rootNode)
end

addCommandHandler("createfile", createFileHandler)

example by Shadowstep07052

 

It shows you how to create a xml file, which has a new child.

 

 

https://wiki.multitheftauto.com/wiki/XmlCreateFile

 

XML syntax:

https://www.tutorialspoint.com/xml/xml_syntax.htm

You there, why are you teaching him to use xml? xml sucks, it uses up 75-90% of the file just to create nodes WITHOUT the values themselves, and it's got complicated af functions. The best way to go for storage is the following:
Internal -
internal database with sqlite
element data
account data
lua tables
External - 
JSON
MYSQL or MariaDB

On 4/23/2018 at 15:48, Master_11 said:

Hi everyone,

I am facing a small problem with tables, well I am not sure how to add something to a table by using addCommandHandler.

 

Like, if this is my table

local random = {
	  --  x   =   y
		['a'] = 'Two',
  		['b'] = 'One',
  		['c'] = 'Ten',
}

Then how can I add another line to this table by a command (addCommandHandler)

For example

If the command is "/add Q A"  ~~~ ("/add d six")

then it should add a new line to the table like ->

local random = {
  
		['a'] = 'Two',
  		['b'] = 'One',
  		['c'] = 'Ten',
  		['d'] = 'Six',
}

On the other hand, I have something like this in my mind for the command:

local random = {
	  --  x   =   y
		['a'] = 'Two',
  		['b'] = 'One',
  		['c'] = 'Ten',
  		['d'] = 'Six',
}


function addabcdtotable(client, commandName, x, y)
	if (blabla ~= "18") then return false end
		if (x) then return false end --(Checks if (['d'] = 'Six',) already exists, if yes then it will simply return {where x = column and y = column-2})
    	Add-> (x,y)	--(This will add {['d'] = 'Six',} to the table)
end
addCommandHandler("add", addabcdtotable)


--For removing a line from table ->


function removeabcdfromtable(client, commandName, x, y)
	if (blabla ~= "18") then return false end
		if (x) then --(Checks if (['d'] = 'Six',) already exists, if yes then it will be removed from the table {where x = column-1 and y = column-2)
			Remove-> (x, y) --(This will remove the whole line and fix the gap ['d'] = 'Six',)
    	else
    		return false end
	end
end
addCommandHandler("rem", removeabcdfromtable)

-- NOW VERY IMPORTANT THE D IS ONLY THE EXAMPLE IT CAN BE ANYTHING LIKE (['ab'] = 'CD',) etc.. {X and Y is not the position please...}

 

Okay and you here, this actually very simple, I'll give you some premium code a little tip before hand however ['a'] is the same as .a, I suggest you start using that. You only want to use [''] method when you have spaces in your string. I'll also show you how to combine commands into a single function and work a table properly.

local items = {}

function commands(player,cmd,name,value)
	if cmd == 'add' then
		if name and value and tonumber(value) then
			if not items[name] then items[name] = tonumber(value) end
		end
	elseif cmd == 'remove' then
		if name and items[name] then
			for i=1,#items do
				if items[i] == items[name] then
					table.remove(items,i)
				end
			end
		end
	elseif cmd == 'test' then
		iprint(items)-- only works on MTA 1.5.5+ servers
	end
end
local cmds = {'add','remove','test'}
for i=1,#cmd do
	addCommandHandler(cmds[i],commands)
end

I hoped this has helped you, if not send me a private message.
Example Command: /add six 6
Example Command: /remove six

And to the rest of you out there, for the love of god please don't use xml, and just because you set a nil value to an item in a table doesn't mean that the item is gone, it's still there it just doesn't have a value..

Edited May 3, 2018 by ShayF

[IIYAMA]

@ShayF

It is not "you" for you, it is IIYAMA. A little bit respect please.

 

Why XML?

- client and server-side support.(giving the user more options)

- Related to html, so more chance that the user would understand it.

- Data read able without tools.

- lots of MTA documentation.

- not required to bind data to a client account.

 

So yes why xml?

Because this user doesn't care about optimization or file size. He want to learn how to do it and I gave him this solution because it matches his profile.

Which is only to learn XML.

 

If you think that the user wants to learn 3 different things:

- accountdata

- Data communication (server/client) The end user is using a GUI.

- JSON

 

Then hmmm, why not everything one step at the time?

 

[ShayF2]

5 hours ago, IIYAMA said:

@ShayF

It is not "you" for you, it is IIYAMA. A little bit respect please.

 

Why XML?

- client and server-side support.(giving the user more options)

- Related to html, so more chance that the user would understand it.

- Data read able without tools.

- lots of MTA documentation.

- not required to bind data to a client account.

 

So yes why xml?

Because this user doesn't care about optimization or file size. He want to learn how to do it and I gave him this solution because it matches his profile.

Which is only to learn XML.

 

If you think that the user wants to learn 3 different things:

- accountdata

- Data communication (server/client) The end user is using a GUI.

- JSON

 

Then hmmm, why not everything one step at the time?

 

json is not that hard to use, its compact and really simplified. You make a lua table, then make a json file, convert the lua table to json with toJSON and then write it to the json file, and when you want to load it you just use fromJSON to convert it back to a lua table. That's why I prefer JSON over everything.

local data = {
	{'blah','blah','blah'},
	{'blah','blah','blah'}
}

function save()
	local file = fileOpen('save.json') or fileCreate('save.json')
	fileWrite(toJSON(data),file)
	fileClose(file)
end

function load()
	if fileExists('save.json') then
		local file = fileOpen('save.json')
		local size = fileGetSize(file)
		local buffer = fileRead(file,size)
		data = fromJSON(buffer)
		fileClose(file)
	end
end

If you were to use different saving methods than xml you would see why I treat it with disrespect. I personally prefer json and mysql.

Edited May 3, 2018 by ShayF

[ShayF2]

For all of you people out there needing to save data, just put it in a lua table and save it with JSON, that is if you want it saved on the server or on the client machine, it's the easiest way to do it. Do NOT use xml, xml is the worst saving method I have ever seen. It's complicated af, it uses tags just like html but other than that it's not even remotely close to html.
XML - 
Hard to learn
Hard to use
Requires a LOT of functions
Uses 75-90% of the file to simply create nodes and or categories
Requires more than 3 XML functions to save or load data
MTA has functions for xml but without them it is not compatible.

JSON or SQLite for permanent local storage.
MYSQL for permanent external storage.
Element Data for temporary storage stored on element.
Account Data for permanent storage stored in the servers internal.db registered to a specific account.

Edited May 3, 2018 by ShayF

[IIYAMA]

You may have disrespect for XML, but I am not XML... lol

Databases are indeed better, just not for new users.

XML hard? I think that is a personal opinion.

More writing code for XML? Yes indeed, but you will know what you will be saving. If you are storing large objects, I am very sure that it might get dirt in it. (Like user data)

JSON? Replacement of XML from Javascript. But can be used within XML. Which means you can parse object models of your choice.

 

Text file client-side?

Bad practice for small updates. Parsing JSON is slow.

\/

If I am would use an interface client-side for client-side data. Would you resave the whole object model for every small update? I do not recommend that.

 

JSON Problem with lua objects.

{G = 33, [2]=444}

After saving + parsing this, the index 2 will be converted to a string. Which can be be a surprising annoying.

 

You might be right about that XML is not as flexible as people would hope. But there are really benefits for it, which it seems you have just to discover.

 

Let's end the discussion here.

 

[Master_11]

I already started working with JSON, I'll update this topic if I face any problem with the code, thanks ShyF and IIYAMA. You guys helped me a lot.

[Master_11]

Could not find the modify buttons ~ So;

 

@ShyF while working on JSON, I found an error on your code, just mentioning if someone could not figure it out in near future.

 

It's

fileWrite(file, toJSON(data))

Not

fileWrite(toJSON(data),file)

 

 

 

 

[ShayF2]

1 hour ago, Master_11 said:

Could not find the modify buttons ~ So;

 

@ShyF while working on JSON, I found an error on your code, just mentioning if someone could not figure it out in near future.

 

It's

fileWrite(file, toJSON(data))

Not

fileWrite(toJSON(data),file)

 

 

 

 

yeah thanks bud, json ftw.

[Master_11]

Thanks, everyone for helping! Moderator may lock this topic.