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12 | Legacy Frameworks |
import current from '/version.js';
Over the years, many frameworks have been released. Some were popular years ago but have waned in recent years. There are still many deployments using these frameworks and it is oftentimes esasier to continue maintenance than to rewrite using modern web techniques.
SheetJS libraries strive to maintain broad browser and JS engine compatibility.
Integration
The "Standalone Browser Scripts" section has
instructions for obtaining or referencing the standalone scripts. These are
designed to be referenced with <script>
tags.
Frameworks
AngularJS
AngularJS was a front-end MVC framework that was abandoned by Google in 2022. It should not be confused with "Angular" the modern framework.
The Live demo shows a simple table that is updated with file data and exported to spreadsheets.
This demo uses AngularJS 1.5.0.
Full Exposition (click to show)
Array of Objects
A common data table is often stored as an array of objects:
$scope.data = [
{ Name: "Bill Clinton", Index: 42 },
{ Name: "GeorgeW Bush", Index: 43 },
{ Name: "Barack Obama", Index: 44 },
{ Name: "Donald Trump", Index: 45 }
];
This neatly maps to a table with ng-repeat
:
<table id="sjs-table">
<tr><th>Name</th><th>Index</th></tr>
<tr ng-repeat="row in data">
<td>{{row.Name}}</td>
<td>{{row.Index}}</td>
</tr>
</table>
The $http
service can request binary data using the "arraybuffer"
response
type coupled with XLSX.read
with type "array"
:
$http({
method:'GET',
url:'https://sheetjs.com/pres.xlsx',
responseType:'arraybuffer'
}).then(function(data) {
var wb = XLSX.read(data.data, {type:"array"});
var d = XLSX.utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
$scope.data = d;
}, function(err) { console.log(err); });
The HTML table can be directly exported with XLSX.utils.table_to_book
:
var wb = XLSX.utils.table_to_book(document.getElementById('sjs-table'));
XLSX.writeFile(wb, "export.xlsx");
Import Directive
A general import directive is fairly straightforward:
- Define the
importSheetJs
directive in the app:
app.directive("importSheetJs", [SheetJSImportDirective]);
- Add the attribute
import-sheet-js=""
to the file input element:
<input type="file" import-sheet-js="" multiple="false" />
- Define the directive:
function SheetJSImportDirective() {
return {
scope: { opts: '=' },
link: function ($scope, $elm) {
$elm.on('change', function (changeEvent) {
var reader = new FileReader();
reader.onload = function (e) {
/* read workbook */
var ab = e.target.result;
var workbook = XLSX.read(ab);
/* DO SOMETHING WITH workbook HERE */
};
reader.readAsArrayBuffer(changeEvent.target.files[0]);
});
}
};
}
Export Service
An export can be triggered at any point! Depending on how data is represented, a workbook object can be built using the utility functions. For example, using an array of objects:
/* starting from this data */
var data = [
{ name: "Barack Obama", pres: 44 },
{ name: "Donald Trump", pres: 45 }
];
/* generate a worksheet */
var ws = XLSX.utils.json_to_sheet(data);
/* add to workbook */
var wb = XLSX.utils.book_new();
XLSX.utils.book_append_sheet(wb, ws, "Presidents");
/* write workbook and force a download */
XLSX.writeFile(wb, "sheetjs.xlsx");
KnockoutJS
KnockoutJS was a popular MVVM framework.
The Live demo shows a view model that is updated with file data and exported to spreadsheets.
Full Exposition (click to show)
State
Arrays of arrays are the simplest data structure for representing worksheets.
var aoa = [
[1, 2], // A1 = 1, B1 = 2
[3, 4] // A1 = 3, B1 = 4
];
ko.observableArray
should be used to create the view model:
function ViewModel() {
/* use an array of arrays */
this.aoa = ko.observableArray([ [1,2], [3,4] ]);
}
/* create model */
var model = new ViewModel();
ko.applyBindings(model);
XLSX.utils.sheet_to_json
with header: 1
generates data for the model:
/* starting from a `wb` workbook object, pull first worksheet */
var ws = wb.Sheets[wb.SheetNames[0]];
/* convert the worksheet to an array of arrays */
var aoa = XLSX.utils.sheet_to_json(ws, {header:1});
/* update model */
model.aoa(aoa);
XLSX.utils.aoa_to_sheet
generates worksheets from the model:
var aoa = model.aoa();
var ws = XLSX.utils.aoa_to_sheet(aoa);
Data Binding
data-bind="foreach: ..."
provides a simple approach for binding to TABLE
:
<table data-bind="foreach: aoa">
<tr data-bind="foreach: $data">
<td><span data-bind="text: $data"></span></td>
</tr>
</table>
Unfortunately the nested "foreach: $data"
binding is read-only. A two-way
binding is possible using the $parent
and $index
binding context properties:
<table data-bind="foreach: aoa">
<tr data-bind="foreach: $data">
<td><input data-bind="value: $parent[$index()]" /></td>
</tr>
</table>