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Displaying one record in a DataGrid at a time
Posted: Sun Sep 06, 2015 7:37 pm
by stevenwhyte
Hi,
I have created a program which displays some graphics cards into a datagrid.
I was wanting to just display one record from the data grid at a time and use a back and forward button to navigate between the records. Is this possible? If so, how do I go about doing it?
I've uploaded the stack that I am working on and was hoping for some help with this if possible...
Many thanks in anticipation,
Steven
Re: Displaying one record in a DataGrid at a time
Posted: Sun Sep 06, 2015 8:27 pm
by Klaus
Hi Steven,
sure this is possible!
Out of my head:
1. Store the array with all records in a custom property of the card or stack: e.g. cCompleteArray
2. Use this syntax to display the first record in the datagrid
...
put the cCompletArray of this cd into tArrayStored
put tArrayStored[1] into tDisplayArray[1]
set the dgdata of grp "datagrid" to tDisplayArray
...
3. Store the current displayed index so you can use this to navigate:
Pseudo pseudo code
Code: Select all
command navigateback
if the cCurrentIndex of this cd = 1 then
beep
exit to top
end if
put the cCurrentIndex of this cd - 1 into tNewIndex
set the cCurrentIndex of this cd to tNewIndex ## !!
put the cCompletArray of this cd into tArrayStored
put tArrayStored[tNewIndex] into tDisplayArray[1]
set the dgdata of grp "datagrid" to tDisplayArray
end naviback
I'll leave the navigateforth handler up to you, you get the picture!
Best
Klaus
Re: Displaying one record in a DataGrid at a time
Posted: Mon Sep 07, 2015 4:18 am
by sritcp
Hi Steven:
If you are going to display only one record at a time, you may choose to use a Basic Table for display purposes. (You can still store the entire data in a datagrid).
You can, for instance,
Code: Select all
put the dgText of group "Datagrid1" into tList
put line 1 of tList into line 2 of field "BasicTable"
(so you can display the column names on line 1 of the basic table).
You can code "Forward" and "Backward" buttons to display each line in tList, one by one.
(You can also use the dgProp["columns"] of group "Datagrid1" to directly load the column names into line 1 of the basic table; but this list is line delimited, so you need to convert it to tab delimited before you feed it to the basic table).
Regards,
Sri
Re: Displaying one record in a DataGrid at a time
Posted: Mon Sep 07, 2015 12:43 pm
by stevenwhyte
Many thanks for your kind replies. You are always so helpful on here.
I will give both techniques a try.
Thanks again!
Steven
Re: Displaying one record in a DataGrid at a time
Posted: Tue Sep 08, 2015 8:26 am
by stevenwhyte
Ok, having a little issue with the code that you supplied me with. Probably something I am doing wrong. I have created a table field and called it "BasicTable" and I've added the following code to a button which includes the two lines at the bottom that you supplied above.
Any chance you could take a look?
Code: Select all
// Allow access to global arrays and variables Setup in main card.
Global arrayName, arrayRam, arrayClockSpeed, arrayCost, MaxCards
On mouseUp
display_cards arrayName, arrayRam, arrayClockSpeed, arrayCost, MaxCards
End mouseUp
On display_cards arrayName, arrayRam, arrayClockSpeed, arrayCost, MaxCards
// Setup local variables
Local theGraphicsCardInfo, CardCount, tList
// Clear text from the fields
Put empty into field "Total Found"
// Display the heading
Put "Displaying All Graphics Cards" into field "Sub Heading"
// Zero number of graphics cards found
Put 0 into CardCount
// Display all graphics cards
Repeat with loop = 1 to MaxCards
// Increment the number of graphics cards displayed.
// This is also used to determine which records will appear in the data grid.
Add 1 to CardCount
// Copy graphics card data from array to data grid
Put arrayName[loop] into theGraphicsCardInfo[CardCount]["name"]
Put arrayRam[loop] into theGraphicsCardInfo[CardCount]["memory"]
Put arrayClockSpeed[loop] into theGraphicsCardInfo[CardCount]["speed"]
Put arrayCost[loop] into theGraphicsCardInfo[CardCount]["cost"]
End Repeat
Set the dgData of Group "DataGrid 1" to theGraphicsCardInfo // Copy list to data grid
Put CardCount into field "Total Found" // Display number of graphics cards found
put the dgData of Group "Datagrid 1" into tList
put line 1 of tList into line 1 of field "BasicTable"
End display_cards
Re: Displaying one record in a DataGrid at a time
Posted: Tue Sep 08, 2015 12:27 pm
by Klaus
The DGDATA of a datagrid is an ARRAY, so you cannot "put line 1 of it" anywhere
Sri was referring to the DGTEXT of the datagrid!
Re: Displaying one record in a DataGrid at a time
Posted: Tue Sep 08, 2015 2:00 pm
by sritcp
Hi Steven:
1. As Klaus pointed out, the DgData of a datagrid is an array, so it has no "lines" in it, only "key" and "value" for each "element".
The same info is made available to us as the DgText of that array, which is a tab-delimited list, and thus, can have lines.
2. If you need to use a datagrid to store, manipulate, and display for other reasons, it's fine.
But once you have chosen BasicTable, you don't need a datagrid simply for displaying that data.
In other words, BasicTable is a (simpler) substitute for datagrid.
So, you can put the data directly into a list. For example,
Code: Select all
set the itemDel to tab
Put arrayName[loop] into item 1 of line CardCount of tList -- here we assume "name" to be item 1, "memory" is item 2, etc
Put arrayRam[loop] into item 2 of line CardCount of tList
...............
put line 1 of tList into line 2 of field "BasicTable" -- You can use line 1 of BasicTable to display column labels such as "name", "memory", etc.
Regards,
Sri
Re: Displaying one record in a DataGrid at a time
Posted: Tue Sep 08, 2015 8:02 pm
by stevenwhyte
Many thanks for all your help! This is working as expected. I should have known that DGData was the group. I had never used DGText before and understand how this works now.
With regards to record navigation, is there an increment command in LiveCode that I can use to automatically increment the line number of tList as I click on the forward button and then decrease the line number when I click on the back button?
I tried:
Code: Select all
Global tList
on mouseUp
Put line 1 of tList into line 2 of field "BasicTable"
Wait until the mouse is up
Put line 2 of tList into line 2 of field "BasicTable"
Wait until the mouse is up
Put line 3 of tList into line 2 of field "BasicTable"
end mouseUp
But it goes straight to the 3rd item in the list when the button is pressed. I know this will be simple but can't think!
Re: Displaying one record in a DataGrid at a time
Posted: Tue Sep 08, 2015 9:38 pm
by Klaus
Hi Steven,
stevenwhyte wrote:...But it goes straight to the 3rd item in the list when the button is pressed.
not really, the script works as exspected!
It will display line 1, then line 2 and then ends up with line 3 in line 2 of your field.
But since in a "mouseup" handler the mouse is ALWAYS up, the script does not wait!
Do something like this:
Code: Select all
Global tList
local tCurrentDisplayedLine
on mouseUp
if tCurrentDisplayedLine = EMPTY OR tCurrentDisplayedLine > 3 then
put 1 into tCurrentDisplayedLine
end if
Put line tCurrentDisplayedLine of tList into line 2 of field "BasicTable"
add 1 to tCurrentDisplayedLine
end mouseUp
Best
Klaus
Re: Displaying one record in a DataGrid at a time
Posted: Wed Sep 09, 2015 7:37 am
by stevenwhyte
Many thanks for your time and help
Re: Displaying one record in a DataGrid at a time
Posted: Wed Sep 09, 2015 8:07 pm
by stevenwhyte
Ok - many thanks for your help. Hopefully one last question. What about the code for the back button.
I've tried:
Code: Select all
Global tList
local tCurrentDisplayedLine
on mouseUp
if tCurrentDisplayedLine = EMPTY OR tCurrentDisplayedLine > 6 then
put -1 into tCurrentDisplayedLine
end if
Put line tCurrentDisplayedLine of tList into line 2 of field "BasicTable"
add -1 to tCurrentDisplayedLine
end mouseUp
The graphics cards go backwards ok but once it reaches the first line, the line is blank.
Thanks in anticipation yet again!
Re: Displaying one record in a DataGrid at a time
Posted: Wed Sep 09, 2015 10:31 pm
by Klaus
Hi Steven,
huh, this is a mentally quite challenging approach!
tCurrentDisplayedLine is never > 6 nor even >=0, since you only have negative numbers in this variable!
I think your field only has 6 lines, but tCurrentDisplayedLine has the value of -7 at some time so you get an empty line!
I would use a less abstract approach
Code: Select all
Global tList
local tCurrentDisplayedLine
on mouseUp
if tCurrentDisplayedLine = EMPTY OR tCurrentDisplayedLine < 1 then
put 6 into tCurrentDisplayedLine
end if
Put line tCurrentDisplayedLine of tList into line 2 of field "BasicTable"
subtract 1 from tCurrentDisplayedLine
end mouseUp
Best
Klaus
Re: Displaying one record in a DataGrid at a time
Posted: Thu Sep 10, 2015 7:34 am
by stevenwhyte
Thanks again