Can a Windows Gadget save data?
Question
I'm creating a small Windows Sidebar Gadget for taking notes in a simple textarea .
I have, as usual, a gadget.xml manifest file and a .html file, see below.
How is it possible to read some data / save some data in a Gadget?
I know this is usually impossible with JavaScript only ( note: using localstorage is not possible because I want persistance of data ), so how to save/read data inside a Windows Gadget ?
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=Unicode" />
<title>NeverForget</title>
<style type="text/css">
body
{
margin: 0;
width: 300px;
height: 200px;
background-color: transparent;
}
#gadgetContent
{
width: 100%;
height: 100%;
overflow: hidden;
border: none;
background-color: transparent;
}
</style>
<script type="text/jscript" language="jscript">
function init() {
// how to load notes from a file here on startup?
}
window.onkeydown = function () {
// how to save data to file?
}
</script>
</head>
<body onload="init()">
<textarea id="gadgetContent">Bonjour</textarea>
</body>
</html>
1 answers
solution1
1 ACCPTED 2015-01-06 10:35:41
Try one of these:
There are the inbuilt methods of the System.Gadget.Settings object which can be used to to read/write from the Settings.ini file (stored in C:\\Users\\[user]\\AppData\\Local\\Microsoft\\Windows Sidebar) but this information will be lost if the gadget is closed or uninstalled.
Use the FileSystemObject to create or read or write folders/files anywhere. Limitation: file can only be saved as unicode or ascii.
Use an ADO Stream object to create or read or write files anywhere. Limitation: can't create folders - must be used in conjunction with the FileSystemObject. Advantage: can use any codepage that exists on your computer.
Since I like saving text files with utf-8 the example below uses the third method but you may well decide to dispense with some of the error handling. (NB - this example is based on a script published by Andrew Urquhart )
Fortunately the sidebar is able to use knownfolders and knownfolderpaths so finding the path to your documents folder for example is as easy as
var docs = System.Shell.knownFolderPath("Documents");
Remember that the backslash is an escape character in javascript so that paths in strings must have their backslashes doubled.
<html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>NeverForget</title> <style type="text/css"> <!-- body {margin:0;width:300px;height:200px;background-color:transparent;padding:10px;} #gadgetContent {width:280px;height:144px;overflow:auto;border:1px solid black;background-color:#eee;} button {margin-left:66px;margin-top:10px;} #message {display:none;width:280px;height:180px;position:absolute;top:10px;left:10px;background-color:#eee;border:1px solid red;} #messageContent {width:278px;height:144px;word-wrap:break-word;overflow-y:auto;} #newButton {position:absolute;bottom:10px;left:54px;} --> </style> <script type="text/jscript"> //globals var myFolderPath=System.Shell.knownFolderPath("Documents")+"\\\\myFiles"; //end globals function showMessage(msg){ message.style.display="block"; messageContent.innerText=msg; } function closeMessage(){ message.style.display="none"; messageContent.innerText=""; } function loadFile(strAbsoluteFilePath, strCharSet){ var adReadAll=-1, adReadLine=-2, strFileContents="", objStream=new ActiveXObject("ADODB.Stream"), fso=new ActiveXObject("Scripting.FileSystemObject"); try{ if(!strAbsoluteFilePath){ throw new Error(1, "Required parameter \\"strAbsoluteFilePath\\" was not defined"); } if(!strCharSet){ throw new Error(2, "Required parameter \\"strCharSet\\" was not defined"); } if(!fso.FolderExists(myFolderPath)){ throw new Error(3, "Folder \\""+myFolderPath+"\\" does not exist"); } objStream.Open(); try{ objStream.CharSet=strCharSet; objStream.LoadFromFile(strAbsoluteFilePath); strFileContents=objStream.ReadText(adReadAll); gadgetContent.innerText=strFileContents; } catch(err){ throw new Error(err.number, "Loading failed:\\r\\n" + err.description); } finally{ objStream.Close(); // Always close the stream regardless of what happens objStream=null; fso=null; } } catch(err){ showMessage("Function loadFile() failed with parameters strAbsoluteFilePath=\\"" + strAbsoluteFilePath + "\\", strCharSet=\\"" + strCharSet + "\\". Message=\\r\\n" + err.description+"\\r\\nError Number: "+err.number); } } function saveFile(strAbsoluteFilePath, strCharSet, strFileContents, blnOverwrite){ var adSaveCreateNotExist=1, adSaveCreateOverWrite=2, objStream = new ActiveXObject("ADODB.Stream"), fso=new ActiveXObject("Scripting.FileSystemObject"); try{ if(!strAbsoluteFilePath){ throw new Error(1, "Required parameter \\"strAbsoluteFilePath\\" was not defined"); } if(!strCharSet){ throw new Error(2, "Required parameter \\"strCharSet\\" was not defined"); } if(typeof strFileContents != "string"){ throw new Error(3, "Required parameter \\"strFileContents\\" was not a string"); } if(!fso.FolderExists(myFolderPath)){ fso.CreateFolder(myFolderPath); } objStream.Open(); try{ objStream.CharSet=strCharSet; objStream.WriteText(strFileContents); objStream.SaveToFile(strAbsoluteFilePath, (blnOverwrite ? adSaveCreateOverWrite : adSaveCreateNotExist)); return true; } catch(err){ throw new Error(err.number, "SaveToFile failed:\\r\\n" + err.description); } finally{ objStream.Close(); // Always close the stream regardless of what happens objStream=null; fso=null; } return false; } catch(err){ showMessage("Function saveFile() failed with parameters strAbsoluteFilePath=\\"" + strAbsoluteFilePath + "\\", strCharSet=\\"" + strCharSet + "\\", strFileContents=\\"" + strFileContents + "\\", blnOverwrite=\\"" + blnOverwrite + "\\". Message=\\r\\n" + err.description+"\\r\\nError Number: "+err.number); } } function init(){ loadButton.onclick=function(){loadFile(myFolderPath+"\\\\myFile.txt","utf-8");}; saveButton.onclick=function(){saveFile(myFolderPath+"\\\\myFile.txt", "utf-8", gadgetContent.innerText, true);}; closeButton.onclick=closeMessage; } </script> </head> <body onload="init()"> <textarea id="gadgetContent">Bonjour</textarea> <div id="message"> <div id="messageContent"></div> <div id="newButton"><button id="closeButton">Close</button></div> </div> <button id="loadButton">Load</button><button id="saveButton">Save</button> </body> </html>
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