data_sheet

Description:

data sheet

DataSheet Widget with Scroll/Edit/Sort/Select Options #
Description #
I was looking for a widget that allows views with fixed header/columns, in-situ editing, locking of cells etc and above all to handle large data.
After searching I did find horizontal_data_table, but it still didn't meet the expectations; so thought of developing myself.
This package is the outcome. I hope you find it useful. You are welcome to comment, contribute to improve the package.
Performance #
Have tried it on android mobile as well as on web with 2048 Rows x 512 columns, without noticing any performance issue.
Features #

Quick and Light Weight widget
Pin Top-rows/ Left-columns so they are always visible
In-situ editing
Auto Scroll to next cell on edit completion
Dropdown suggestions
Adjustable Column widths
Decoration/Style for rows, columns
Select/deselect cell/rows
Allows custom widgets as cell content

Installation #
Install data_table
flutter pub add data_table
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Demo #






Usage/Examples #
import 'data_table/data_table'
/// --------------------------------------
/// Build parametes to be passed
/// --------------------------------------

List<CellSetup> _cellSetups = [
CellSetup(selected:_selected),
CellSetup(
textInputType:TextInputType.name,
defaultSort: EditAction.sortA2Z, selected:_selected),
CellSetup(
suggestions:_suggestGender,
action:SuggestionsAction.restrict,
defaultSort: EditAction.sortNone),
CellSetup(
suggestions:_suggestCountry,
textInputType:TextInputType.name,
defaultSort: EditAction.sortZ2A,
triStateSort:false),
CellSetup(
suggestions:_suggestFood,
getWidget: _getCustomeCellWidget,
action:SuggestionsAction.keep,
textInputType:TextInputType.name),
CellSetup(textInputType:TextInputType.number),
];

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Example of Usage. The utility of parameters is explained along side each parameter. Detailed explanation is given in Parameter Notes
/// --------------------------------------
/// The Widget
/// --------------------------------------

DataTable(
data:_data, // List<List<String>>
onUpdate: onUpdate, // callback, refer note below
onSelectCell:onSelectCell, // callback
cellSetups:_cellSetups, // List<CellSetup>

isEditing: true, // Setting it true/false will make the widget editable/read-only

outerController: outerController, // Scroll controller of parent widget (if scrollable), can be null
outerPhysics: outerPhysics, // Required in pair with outerController parameter

pinnedRows: _pinnedRows, // Pinned top row (int)
pinnedCols: _pinnedCols, // Pinned left columns (int)

cellSize: const Size(100,kToolbarHeight*0.7),

columnWidths:const [0.15,0.3,0.2,0.2,0.2, 0.2],
columnWidthOption: ColumnWidthOption.ratio,

decoPinnedRow: [ // List<BoxDecoration>
_decoPinnedRow1,
_decoPinnedRow2,
],
decoPinnedCol: [ _decoPinnedCol1,], // List<BoxDecoration>
decoNormal: _decoNormalCell, // BoxDecoration
stylePinnedRowText:
_stylePinnedRowText, // TextStyle
stylePinnedColText:
_stylePinnedColText, // TextStyle
styleNormalCellText:
_styleNormalCellText, // TextStyle
);
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Parameter Notes #
data:

Contains values of all columns & rows in String format. The user shall populate this List converting all the values to String and ultimately List<List

/// Sample of preparing Friends class to pass on to [data]
_bodyPage3 = _friends.map((e) {
return [
'${e.id}',
e.name,
e.gender,
e.country,
e.food,
DateFormat('dd-MMM-yyyy')
.format(DateTime.fromMillisecondsSinceEpoch(e.dobEpoch)),
e.weight.toStringAsFixed(1),
e.height.toStringAsFixed(1)
];
}).toList();

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onUpdate: This is the main callback function the widget calls after the user performs edit, sort operation. The functions passes a dynamic value related to the cell identified by row & column number along with action taken. It is users responsibility to handle the passed value for correctness and updating the same.

bool onUpdate(int row, int col, dynamic value, EditAction action) {
late String str, newValue;
double? val;
int count = 0;

str = '';
switch (action) {
case EditAction.add:
List<String> nl = List.generate(_header1.length, (index) {
return index == 0 ? '${_dataPage3.length - _pinnedRows + 1}.' : '';
});
...
...
break;
case EditAction.delete:
int rowNo = _curRow - _pinnedRows;
setState(() {
_bodyPage3.removeAt(rowNo);
_selected.removeAt(rowNo);
if (_curRow >= _bodyPage3.length + _pinnedRows) _curRow--;
for (int i = rowNo; i < _bodyPage3.length; i++) {
_bodyPage3[i][0] = '${i - _pinnedRows + 1}.';
}
});
break;
case EditAction.sortNone:
_bodyPage3.sort((a, b) => a[0].compareTo(b[0]));
break;
case EditAction.sortA2Z:
_bodyPage3.sort((a, b) => a[col].compareTo(b[col]));
break;
case EditAction.sortZ2A:
_bodyPage3.sort((b, a) => a[col].compareTo(b[col]));
break;
case EditAction.select:
_selected[row] = value;
...
...
break;
case EditAction.selectAll:
...
...
break;
default:
break;
}

...
...

switch (col) {
case 1: // Name
case 3: // Country
case 4: // Food
newValue = value;
break;
case 2: // Gender
newValue = value.substring(0, 1).toUpperCase();
break;
case 5: // DOB
try {
newValue = DateFormat('dd-MMM-yyyy').format(value);
} catch (fe) {
str = fe.toString();
}
break;
case 6: // Weight
case 7: // Height
val = double.tryParse(value);
if (val != null) {
newValue = val.toStringAsFixed(1);
} else {
str = "Input must be a number";
}
break;

default:
assert(false);
break;
}
if (str.isNotEmpty) {
...
/// Report Error
} else {
setState(() {
_dataPage3[row][col] = newValue;
});
}

return str.isEmpty;
}

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onSelectCell: Callback function, called by DataSheet when a select checkbox is tapped on


cellSetups: A [List


isEditing: Setting it true/false will make the widget editable/read-only


moveNextAfterEdit: If true, moves to & selects editing for next cell, after editing of currently selected cell is complete.


outerController / outerPhysics: Scroll controller of parent widget (if scrollable), can be null. The outerPhysics parameter is required in pair with outerController parameter, else it can be null.


pinnedRows: Number of pinned (fixed) top row(s), This is like header of the sheet. Top row(s) given by this parameter will be always visible during scroll.



pinnedCols: Number of pinned (fixed) left columns(s). The left column(s) given by this parameter will be always visible during scroll.


cellSize: You can define default Cell Size here


columnWidths: A List


columnWidthOption: Refer comments above,


decoPinnedRow/decoPinnedCol/decoNormal: BoxDecorations for Pinned Row Cells, Pinned Column Cells and Normal Cells respectively.


stylePinnedRowText/stylePinnedColText/styleNormalCellText: TextStyles for Pinned Row Cells, Pinned Column Cells and Normal Cells respectively.


About Me #
Though I have been developing software for industry automation, astrology, office tools etc. for many years, I am relatively new to Flutter/mobile apps.
Flutter's quick app development fascinates me. Looking for app usage for varied applicability.
License #
MIT
This is the first time I am publishing a package, there might be some errors/mistakes. Also, some of the entries (like contributing.md, code of conduct etc.) are incomplete. Please feel free to correct.
Acknowledgements #

The easiest way to create a README
Awesome README
How to write a Good readme
Help on Contributing.md

Contributing #
Contributions are always welcome!
See contributing.md for ways to get started.
Please adhere to this project's code of conduct.