Read pubspec.yaml from dart code in Flutter? - dart

I want to get access to the pubspec.yaml and read its properties from dart code in my Flutter application, while the application is running. How can I do so?
PS: I want to read the name, description and version properties from the pubspec during the application runtime!

Since you just need to fetch the name, description, and version of the app from the pubspec.yaml, you can use package_info_plus plugin to query these properties.
PackageInfo packageInfo = await PackageInfo.fromPlatform();
String appName = packageInfo.appName;
String version = packageInfo.version;

Related

Dart 2.17.0: how do I enable "enhanced-enums"?

Code example:
enum ShareType {
NONE('N'),
PUBLISH('P'),
SHARE('S');
final String key;
const ShareType(String keyToSet) {this.key = keyToSet;}
}
gives error:
This requires the 'enhanced-enums' language feature to be enabled.
How do I enable this feature?
Where must this be set?
Go into your pubspec.yaml file in your project and make sure that the minimum version for the sdk are 2.17.0 like:
environment:
sdk: ">=2.17.0 <3.0.0"
The reason for this is that Dart keeps track of when features are introduced and makes sure your project does not make use of features that would not be compatible for the range of versions your project have specified as required.

How to get the Project name with the new azure-devops-extension-sdk?

In the older SDK (vss-web-extension-sdk) - we could use VSS.getWebContext() to get the project name and id. I coudln't find a similar method in the newer SDK (azure-devops-extensions-sdk)
How can I get the project name with the new azure-devops-extensions-sdk?
There are samples azure-devops-extension-sample
Sample code:
import * as SDK from "azure-devops-extension-sdk";
import { CommonServiceIds, IProjectPageService } from "azure-devops-extension-api";
const projectService = await SDK.getService<IProjectPageService>(CommonServiceIds.ProjectPageService);
const project = await projectService.getProject();
https://github.com/microsoft/azure-devops-extension-sample/blob/master/src/Samples/Hub/OverviewTab.tsx
In the azure-devops-extension-sdk package I have not found an interface that can meet your need, but there is an IProjectInfo interface in the azure-devops-extension-api package could meet your demand.You could try it.
You could also try calling a REST API from your client-side extension to get project name. Here is the rest api as a reference:
curl -u {username}[:{personalaccesstoken}] https://dev.azure.com/{organization}/_apis/projects?api-version=2.0
For details,you can refer to this docs.

How to read and write a text file in Flutter

How do you read text from a file and write text to a file?
I've been learning about how to read and write text to and from a file. I found another question about reading from assets, but that is not the same. I will add my answer below from what I learned from the documentation.
Setup
Add the following plugin in pubspec.yaml:
dependencies:
path_provider: ^1.6.27
Update the version number to whatever is current.
And import it in your code.
import 'package:path_provider/path_provider.dart';
You also have to import dart:io to use the File class.
import 'dart:io';
Writing to a text file
_write(String text) async {
final Directory directory = await getApplicationDocumentsDirectory();
final File file = File('${directory.path}/my_file.txt');
await file.writeAsString(text);
}
Reading from a text file
Future<String> _read() async {
String text;
try {
final Directory directory = await getApplicationDocumentsDirectory();
final File file = File('${directory.path}/my_file.txt');
text = await file.readAsString();
} catch (e) {
print("Couldn't read file");
}
return text;
}
Notes
You can also get the path string with join(directory.path, 'my_file.txt') but you need to import 'package:path/path.dart'.
Flutter's Official Documentation of Reading and Writing Files
This works for iOS, Android, Linux and MacOS but not for web.
As additional info to #Suragch's answer, if you want to find the file you created, you can do as the images show:
And then inside that data folder, go again to a folder named data and search for your package, and then go to:
If you happen to create new files, in order to be able to see them, just right click and click Synchronize.
An another way to pull the file from the device is by using adb pull command. You can find the file path by debugging the code and then use adb pull command. adb is located in Android SDK -> platform-tools directory.
./adb pull /storage/emulated/0/Android/data/com.innovate.storage.storage_sample/files/sample.txt ~/Downloads
#Suragch 's answer is right. Except the version of path_provider that you want to use now is:
path_provider: ^2.0.9

How to add a File Picker plugin in Flutter?

I am creating a Flutter project in which, I have a piece of data (JSON) that I want to Import from and Export to a location the user wants to. In order to achieve this, I require a File Picker plugin in Flutter. Now, I searched the Dart Packages repository for "file picker" but didn't find one.
Is there a way to get a File Picker that looks like this:
or even this...
The first screenshot is preferable for me as it allows file selection from different sources (like Drive).
Also, since I want to Export the data, I might want a Folder Picker too. ;)
But, if there is any other alternative to Folder Picker. I'd be happy to know...
I've created a file_picker plugin some time ago in order to make it possible to pick (both on iOS and Android) absolute paths and then loaded it with Flutter.
You can check it here: https://pub.dev/packages/file_picker
I used file_picker library to pick files. you can use this for pick images as well.
Future getPdfAndUpload(int position) async {
File file = await FilePicker.getFile(
type: FileType.custom,
allowedExtensions: ['pdf','docx'], //here you can add any of extention what you need to pick
);
if(file != null) {
setState(() {
file1 = file; //file1 is a global variable which i created
});
}
}
here file_picker flutter library.
I'm in the exact same boat as you, haha!
I noticed documents_picker 0.0.2. It allows the user to pick multiple files, and it seems to fit the need!
check it out: https://pub.dartlang.org/packages/documents_picker#-readme-tab-
Here's a better document picker. It looks like the native document picker from the Storage Access Framework, which is what you have in your picture.
flutter_document_picker
Just found the FileSelector plugin from flutter.dev. Compatible with MacOS, Windows and Web.
From its pub.dev page:
Open a single file
final typeGroup = XTypeGroup(label: 'images', extensions: ['jpg', 'png']);
final file = await openFile(acceptedTypeGroups: [typeGroup]);
Open multiple files at once
final typeGroup = XTypeGroup(label: 'images', extensions: ['jpg', 'png']);
final files = await openFiles(acceptedTypeGroups: [typeGroup]);
Saving a file
final path = await getSavePath();
final name = "hello_file_selector.txt";
final data = Uint8List.fromList("Hello World!".codeUnits);
final mimeType = "text/plain";
final file = XFile.fromData(data, name: name, mimeType: mimeType);
await file.saveTo(path);
MacOS: Provide file read or/and write privileges
On target MacOS please provide sufficient rights using Xcode:
In case you don't provide file read or/and write permissions, the call to
final XFile? file =
await openFile(acceptedTypeGroups: <XTypeGroup>[typeGroup]);
neither shows anything not returns.

Access to pubspec.yaml attributes (version) from Dart app

Is there any way to access some of the attributes listed in a pubspec.yaml file in that files Dart application?
In particular, the version and description attributes may be quite useful to see in a version info dialog, or even a '--version' when using a console app. I haven't been able to find a way to access in the API. I'm not sure if Mirrors would have anything appropriate, but if a web app is compiled to JS, then I don't see the description anywhere in the output JS.
Thanks.
EDIT
feature request: https://code.google.com/p/dart/issues/detail?id=18769
FOR FLUTTER ONLY
Please use this new package package_info_plus from flutter community.
import 'package:package_info_plus/package_info_plus.dart';
PackageInfo packageInfo = await PackageInfo.fromPlatform();
String appName = packageInfo.appName;
String packageName = packageInfo.packageName;
String version = packageInfo.version;
String buildNumber = packageInfo.buildNumber;
BELOW SOLUTION IS DEPRICATED.
I know the OP wants to read YAML but for flutter dev's you guys can read the version and other info of the application using package_info.
This is the sample to fetch details from Android/iOS application.
import 'package:package_info/package_info.dart';
PackageInfo packageInfo = await PackageInfo.fromPlatform();
String appName = packageInfo.appName;
String packageName = packageInfo.packageName;
String version = packageInfo.version;
String buildNumber = packageInfo.buildNumber;
you can install the "dart_config" package and use this code to parse a pubspec.yaml file:
import 'package:dart_config/default_server.dart';
import 'dart:async';
void main() {
Future<Map> conf = loadConfig("../pubspec.yaml");
conf.then((Map config) {
print(config['name']);
print(config['description']);
print(config['version']);
print(config['author']);
print(config['homepage']);
print(config['dependencies']);
});
}
The output looks similar to this:
test_cli
A sample command-line application
0.0.1
Robert Hartung
URL
{dart_config: any}
EDIT
You can do it with the Yaml package itself:
*NOTE: this will not work on Flutter Web
import 'package:yaml/yaml.dart';
import 'dart:io'; // *** NOTE *** This will not work on Flutter Web
void main() {
File f = new File("../pubspec.yaml");
f.readAsString().then((String text) {
Map yaml = loadYaml(text);
print(yaml['name']);
print(yaml['description']);
print(yaml['version']);
print(yaml['author']);
print(yaml['homepage']);
print(yaml['dependencies']);
});
}
Regards Robert
None of the above answers worked for me, but here's a working solution for a Flutter app:
In your pubspec.yaml add the "pubspec.yaml" to assets:
assets:
- assets/
- pubspec.yaml
If you have a widget where you need to show the app version like this:
...
Container(
child: Text('Version: 1.0.0+1'),
),
...
Wrap your widget with a FutureBuilder like this:
import 'package:flutter/services.dart';
import 'package:yaml/yaml.dart';
...
FutureBuilder(
future: rootBundle.loadString("pubspec.yaml"),
builder: (context, snapshot) {
String version = "Unknown";
if (snapshot.hasData) {
var yaml = loadYaml(snapshot.data);
version = yaml["version"];
}
return Container(
child: Text(
'Version: $version'
),
);
}),
...
The services rootBundle property contains the resources that were packaged with the application when it was built.
If you want to show the version without the build number, you can split the string like so:
'Version: ${version.split("+")[0]}'
UPDATE: As mentioned by #wildsurfer, this approach has a potential security risk in web development because the pubspec.yaml is shared with the browser!
So assuming that this is for a dart cli application then the #Robert suggestion won't work.
dart_config isn't available for dart 2.x and your pubspec.yaml isn't going to be relative to your cwd except when you are in your development environment
So you need to get the pubspec.yaml relative to the libraries executable path.
This example uses the 'paths' package but it isn't required.
This can be obtained by:
import 'package:path/path.dart';
String pathToYaml = join(dirname(Platform.script.toFilePath()), '../pubspec.yaml');
You can now read the yaml:
import 'package:path/path.dart';
import 'package:yaml/yaml.dart';
String pathToYaml = join(dirname(Platform.script.toFilePath()), '../pubspec.yaml');
File f = new File(pathToYaml);
String yamlText = f.readAsStringSync();
Map yaml = loadYaml(yamlText);
print(yaml['name']);
print(yaml['description']);
print(yaml['version']);
print(yaml['author']);
print(yaml['homepage']);
print(yaml['dependencies']);
});
For Flutter only (Web, Android and IOS)... since October 2020
If you want your app working on Web, Android and IOS use "Package info_plus" instead.
How to Incorporate Automated Version Information into A Dart Command Line App
To update version information in your code without having to package a resource file to be parsed during run time, you can have the information hard coded into an automatically generated dart source file which gets compiled into your binary. The following example hard codes the version, name, and description information into the Map object "meta" in a meta.dart file. The meta.dart file is recreated and overwritten every time the test suite is run in development. To verify the source code has the correct version information, the app's code verifies the version and other meta information against the attributes in the pubspec.yaml file (but only when run as interpreted code in development). If there is a difference from pubspec.yaml, it throws an exception. Once compiled into a binary, it will skip that check as it won't find the pubspec.yaml file, so no error is thrown from the binary. Even if a pubspec.yaml file happens to be around and is found, it only throws an exception and does not create a "meta.dart" source file.
1. Create a MetaUpdate class and save it as "meta_update.dart":
import 'dart:io';
import 'package:yaml/yaml.dart';
import 'meta.dart';
class MetaUpdate {
String pathToYaml = "";
String metaDartFileContents = "";
MetaUpdate(this.pathToYaml);
void writeMetaDartFile(String metaDartFilePath) {
File metaDartFile = File(metaDartFilePath);
String metaDartFileContents = """
/// DO NOT EDIT THIS FILE EXCEPT TO ENTER INITIAL VERSION AND OTHER META INFO
/// THIS FILE IS AUTOMATICALLY OVER WRITTEN BY MetaUpdate
Map<String, String> meta = <String, String>{
"name": "${getPubSpec('name')}",
"description":
// ignore: lines_longer_than_80_chars
"${getPubSpec('description')}",
"version":"${getPubSpec('version')}",
};
""";
metaDartFile.writeAsStringSync(metaDartFileContents);
}
String getPubSpec(String pubSpecParam) {
File f = File(pathToYaml);
String yamlText = f.readAsStringSync();
// ignore: always_specify_types
Map yaml = loadYaml(yamlText);
return yaml[pubSpecParam];
}
void verifyLatestVersionFromPubSpec() {
try {
File f = File(pathToYaml);
//exit if no pubspec found so no warning in production
if (!f.existsSync()) return;
//compare meta.dart with pubspec meta and give warning if difference
if (meta.keys
.where((dynamic e) => (meta[e] != getPubSpec(e)))
.isNotEmpty) {
throw Exception(
"""Version number and other meta attributes in code are different from pubspec.yaml. Please check pubspec.yaml and then run test so that MetaUpdate can update meta information in code, then recompile""");
}
} on Exception {
rethrow;
}
}
}
2. Create a "meta.dart" file:
/// DO NOT EDIT THIS FILE EXCEPT TO ENTER INITIAL VERSION AND OTHER META INFO
/// THIS FILE IS AUTOMATICALLY OVER WRITTEN BY MetaUpdate
Map<String, String> meta = <String, String>{
"name": "Acme Transmogrifier",
"description":
"The best dart application ever.",
"version":"2021.09.001",
};
When you initially create the meta.dart file, copy your specific info from pubspec.yaml. This will later be overwritten each time your MetaUpdate.writeMetaDartFile() is run, changing the contents whenever the info in pubspec.yaml is changed.
3. Implement The Version Update In Your Test Code
Add the following in the first line of Main() in your test code (not the source of the main program, we don't want it to be compiled into the binary), changing the path to meta.dart as appropriate:
MetaUpdate("pubspec.yaml").writeMetaDartFile("lib/src/meta.dart");
4. Add A Meta Check To Your Main Code
Put this in your app's code so it is one of the first methods executed when your app is run - it will generate an exception if there is a difference between the attributes shown in the meta.dart and pubspec.yaml:
MetaUpdate("pubspec.yaml").verifyLatestVersionFromPubSpec();
5. Using
Make sure the Name, Version, and Description information in pubspec.yaml contains the latest information you want reflected in your code.
Import "meta.dart" and insert meta['name'], meta['version'], etc. where you need them to be shown (e.g., in --help or --version messages to be printed to the console).
As long as you run your tests before compiling your code the meta information will be accurately reflected in your code.
You can access pubspec.yaml properties with the official pubspec_parse package from the Dart team.
dart pub add pubspec_parse
import 'dart:io';
import 'package:pubspec_parse/pubspec_parse.dart';
final pubspec = File('pubspec.yaml').readAsStringSync();
final parsed = Pubspec.parse(pubspec);
You can then access typed properties on the parsed object.
You can find supported properties here: https://pub.dev/documentation/pubspec_parse/latest/pubspec_parse/Pubspec-class.html.

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