I'm fairly new to Dart and Flutter, and I'm having trouble to overwrite an existing assets image from a source image.
My attempt:
try {
File localFile = File('assets/images/myImage.png');
localFile.writeAsBytesSync(originFile.readAsBytesSync());
catch (e) {
log(e.toString());
}
I get:
[log] FileSystemException: Cannot open file, path = 'assets/images/myImage.png' (OS Error: No such file or directory, errno = 2)
I did define the assets folder in pubspec.yaml:
assets:
- assets/images/
Ok, so I've read somewhere that the asset file can be accessed like this:
import 'package:flutter/services.dart' show rootBundle;
final byteData = await rootBundle.load('assets/images/myImage.png');
But I don't know how to convert byteData to a File object that represents the actual file.
I think I'm missing something very basic here. Or maybe is there is a proper way to do this that has nothing to do with this approach?
Please help.
Thanks in advance!
If you want to write a file on a user device you should look here: https://flutter.dev/docs/cookbook/persistence/reading-writing-files
Shared preferences are a space in a phone where you app can write, so it's exactly what you want!
Assets are part of you app and are not meant to be modified within the app.
During a build, Flutter places assets into a special archive called
the asset bundle that apps read from at runtime. According to the flutter website
Hope this helps!
I'm creating a project of a school. I want to show the uploaded stuff by teachers to students.
But I also need to save the file in the folder which is named as faculty name. Student will be able to browse the main directory and after that he can go in the particular faculties folder.
How can I do it? Any suggestions will be appreciated.
For file upload I would start with example like in this answer. Moving files from temporary folder could be easily done by the file uploading action.
For browsing files in your case I would create an action that is able to navigate to the folder where the files are and get a list of files from that folder. Something like this
String file = application.getRealPath("/upload");
File f = new File(file);
String [] fileNames = f.list();
File [] fileObjects= f.listFiles();
for (int i = 0; i < fileObjects.length; i++) {
if(!fileObjects[i].isDirectory()){
String fname = file+fileNames[i];
out.println(fileNames[i]);
}
}
Then map this files to the JSP as links. When that link is clicked you can retrieve the actual path on the server when action is executed. What to do with the data, of course you can return stream result from the action that is used for streaming to the client browser. You can use docs examples from the Struts site or like in this example.
To navigate to the folder use parameters in GET request, that will be used to store current directory in session. You can change it if a user change the current directory from the view layer.
Needs to include this file (http://trailers.apple.com/appletv/us/js/application.js) in a Meteor.js project.
The file can't be in the public folder, and it has to be under PROJECT_ROOT/appletv/us/js/ folder.
But whenever I include the file, it crashes Meteor.
Any advice on how to ignore this arbitrary file in an arbitrary folder?
Just add
atv = {};
To the first line of this application.js
Other solution
Move your application.js to /lib, then create /lib/lib/hack.js
So your project will be:
<project>/lib/lib/hack.js
<project>/lib/application.js
<project>/*stuff*
And put
atv = {};
As the content of hack.js
Why can't it be in /public? /public is copied to the root of the server when deployed. So /public/appletv/us/js/application.js will be app.com/appletv/us/js/application.js when running.
How do I write a Google Apps Script that deletes files?
This finds files:
var ExistingFiles = DocsList.find(fileName);
But DocsList.deleteFile does not exist to delete a file.
Is there a way to move those files to another Folder or to Trash?
The other workaround I would consider is to be able to override an existing file with the same name.
Currently when I want to create a file with a name already used in MyDrive then it creates a second file with the same name. I would like to keep 1 file (the new one is kept and the old one is lost).
There are 3 services available to delete a file.
DriveApp - Built-in to Apps Script
Advanced Drive Service - Built-in to Apps Script but must be enabled. Has more capability than DriveApp
Google Drive API - Not built-in to Apps Script, but can be used from Apps Script using the Drive REST API together with UrlFetchApp.fetch(url,options)
The DocsList service is now deprecated.
The Advanced Drive Service can be used to delete a file without sending it to the trash. Seriously consider the risk of not being able to retrieve the deleted file. The Advanced Drive Service has a remove method which removes a file without sending it to the trash folder. Advanced services have many of the same capabilities as the API's, without needing to make an HTTPS GET or POST request, and not needing an OAuth library.
function delteFile(myFileName) {
var allFiles, idToDLET, myFolder, rtrnFromDLET, thisFile;
myFolder = DriveApp.getFolderById('Put_The_Folder_ID_Here');
allFiles = myFolder.getFilesByName(myFileName);
while (allFiles.hasNext()) {//If there is another element in the iterator
thisFile = allFiles.next();
idToDLET = thisFile.getId();
//Logger.log('idToDLET: ' + idToDLET);
rtrnFromDLET = Drive.Files.remove(idToDLET);
};
};
This combines the DriveApp service and the Drive API to delete the file without sending it to the trash. The Drive API method .remove(id) needs the file ID. If the file ID is not available, but the file name is, then the file can first be looked up by name, and then get the file ID.
In order to use DriveAPI, you need to add it through the Resources, Advanced Google Services menu. Set the Drive API to ON. AND make sure that the Drive API is turned on in your Google Cloud Platform. If it's not turned on in BOTH places, it won't be available.
Now you may use the following if the file is as a spreadsheet, doc etc.:
DriveApp.getFileById(spreadsheet.getId()).setTrashed(true);
or if you already have the file instead of a spreadsheet, doc etc. you may use:
file.setTrashed(true);
This code uses the DocsList Class which is now deprecated.
try this :
function test(){
deleteDocByName('Name-of-the-file-to-delete')
}
function deleteDocByName(fileName){
var docs=DocsList.find(fileName)
for(n=0;n<docs.length;++n){
if(docs[n].getName() == fileName){
var ID = docs[n].getId()
DocsList.getFileById(ID).setTrashed(true)
}
}
}
since you can have many docs with the same name I used a for loop to get all the docs in the array of documents and delete them one by one if necessary.
I used a function with the filename as parameter to simplify its use in a script, use test function to try it.
Note : be aware that all files with this name will be trashed (and recoverable ;-)
About the last part of your question about keeping the most recent and deleting the old one, it would be doable (by reading the last accessed date & time) but I think it is a better idea to delete the old file before creating a new one with the same name... far more logical and safe !
Though the The service DocsList is now deprecated, as from the Class Folder references, the settrashed method is still valid:
https://developers.google.com/apps-script/reference/drive/folder#settrashedtrashed
So should work simply this:
ExistingFiles.settrashed(true);
Here is another way to do it without the need of Drive API. (based on Allan response).
function deleteFile(fileName, folderName) {
var myFolder, allFiles, file;
myFolder = DriveApp.getFoldersByName(folderName).next();
allFiles = myFolder.getFilesByName(fileName);
while (allFiles.hasNext()) {
file = allFiles.next();
file.getParents().next().removeFile(file);
}
}
Here is a slightly modified version using the above. This will backup said file to specified folder, also remove any old previous backups with the same name so there are no duplicates.
The idea is here to backup once per day, and will retain 1 month of backups in your backup folder of choice. Remember to set your trigger to daily in your Apps Script.
https://gist.github.com/fmarais/a962a8b54ce3f53f0ed57100112b453c
function archiveCopy() {
var file = DriveApp.getFileById("original_file_id_to_backup");
var destination = DriveApp.getFolderById("backup_folder_name");
var timeZone = Session.getScriptTimeZone();
var formattedDate = Utilities.formatDate(new Date(),timeZone,"dd"); // 1 month backup, one per day
var name = SpreadsheetApp.getActiveSpreadsheet().getName()+"_"+formattedDate;
// remove old backup
var allFiles = destination.getFilesByName(name);
while (allFiles.hasNext()) {
var thisFile = allFiles.next();
thisFile.setTrashed(true);
};
// make new backup
file.makeCopy(name,destination);
}
In my Grails application I need to create a file in current system in which I need to save information fetched from table in database. How to do this from within controller action? I don't have any idea of it.
I have created file as
File file=new File("file name.txt")
file.createNewFile();
then I have wrote values of MySQL database table fields in it as:
file<<patient.id
file<<patient.name
.
.
.
it stores data like continuous text but I want to have a .doc file in which data should get stored in table. I found Apache's POI for creating doc file but I am not getting how it works and how I should use it.
Not sure exactly what you want to store in a file but below is an example of how to easly write a String to a file using Apache-commons-io Which should be included in grails
import org.apache.commons.io.FileUtils;
class SomeController{
def writeToFile = {
def data = getSomeStringData();
def fileStore = new File("./path/to/files/ControllerOutput_${new Date()}.txt");
fileStore.createNewFile();
FileUtils.writeStringToFile(fileStore, data);
println("your file was created # {fileStore.absolutePath} and is ${fileStore.length()} bytes");
}
}
Does this help? If not, you need to explain exactly what your looking for.
This is a comment to Michael's answer (unfortunately I still don't have the reputation to reply on answers).
If you're struggling around the problem how to specifiy the relative path from within your controller's context, this might help you:
So if you have following folder you want to read/write files from/into"..
/myproject/web-app/temp/
you can access the file like this:
import org.codehaus.groovy.grails.commons.ApplicationHolder as AH
// getResource references to the web-app folder as root folder
Resource resource = AH.getApplication().getParentContext().getResource("/temp/myfile.txt)