The code_build (https://pub.dartlang.org/packages/code_builde) package provides a solution to generate classes and constructors, field and methods for that class.
My ultimate goal is to generate Flutter (https://flutter.io) Widgets based on the json structure given, but I don't know how to do this with the code_build or another package.
So help would be appreciated!
The general way to write something which outputs Dart code is to wrap up the functionality in a Builder and to perform the code generation with build_runner
At a high level you'd write a Builder that:
Has buildExtensions of {".json": [".dart"]}.
Reads in the buildStep.inputId asset and parses the json.
Uses code_builder to build up a String and then write it to the output asset.
Then you'd configure the builder in build.yaml. And either apply it manually to your package, or if you'd like to publish it as a utility it can apply to dependencies.
Your package would have a dev_dependency on build_runner and then you can execute builds with flutter packages run build_runner build.
There are more docs at https://github.com/dart-lang/build/tree/master/docs
You can see an example of a package which does something similar - starts with yaml files and outputs Dart files using code_builder at https://github.com/natebosch/message_builder
There is now an online tool which will generate the Dart classes from a JSON payload if you're only looking to structure your model classes. It won't do it dynamically at runtime, but it's super helpful when you're first building your program.
https://javiercbk.github.io/json_to_dart/
Related
On my way to migrate an existing build to bazel, i have a submodule mod1 that has some JUnit tests reading files from a "testdata" directory. When trying to load those files, i have to use "mod1/testdata/test.txt" instead of "testdata/test.txt", i.e. the unit tests have to be aware of their corresponding bazel module directory.
(1) Is this the correct behaviour for bazel 0.23.2#debian and 0.23.2-homebrew?
(2) Is there a way to use the .java tests without changes, and to remove the need for a "mod1" prefix in bazel data/ runfiles?
My sample project is here: https://gitlab.com/jhinrichsen/bazel-data-test. I am looking for a way to use the same path "testdata/test.txt" for both root module and submodule. In my example project, bazel test AllTests suceeds, while bazel test mod1/AllTests fails because i need to prepend "mod1/" to "testdata/test.txt".
Not looking for a resources/classpath based solution as i cannot modify the existing test sources.
The behavior that you are seeing is indeed the correct behavior, and there is no way to strip the "mod1" prefix with the native Java rules. Anything you include with data will be scoped to its own package in the way you're seeing.
The reason for this is pretty straightforward. Let's say that your test target, //mod1:AllTests, also depended on a hypothetical //mod2:tests library. And let's say that hypothetical library also had a testdata/test.txt as a data dependency. The multiple test.txt files would conflict unless they were namespaced to their packages.
If you absolutely cannot modify the test source at all, then you are pretty much stuck. Here's a previous discussion about this:
https://groups.google.com/forum/#!topic/bazel-discuss/w6TDwSZvN0k
I would recommend if you're trying to work with Bazel, you accept the concept of runfiles and modify your tests to either work with the runfiles structure, or accept a command-line argument for where to find the test data.
In a Flutter app, I have a dart file located at FlutterTest\sandbox\lib\my_widget\my_widget.dart, containing a class called MyWidget.
Can I, from this class, get the location of the file where it is defined?
This is not possible. Flutter disable dart:mirror so you can't use reflection.
As mentioned in another answer/comments, that information is stripped out at runtime.
However, if you're motivated enough you could write a pub transformer that uses regex to pick up a special symbol you define and exchange it for the file path at runtime. Edit: transformers aren't supported in flutter.
You may be able to do this with the Build package & tooling introduced in Dart 2, but you'll have to make sure you're using a version of flutter that uses dart 2 (the beta branch/channel probably doesn't yet, the dev may or may not, but master does).
I'm building up some Dart code that I would like to use in an app where it is essentially a library to the javascript. I'm wondering how I can specify which Dart files I'd like in the project to be part of the library. For example, theres Foo.dart and Bar.dart. How can I have the created product include both Foo.dart and Bar.dart in one file? I'm also concerned about tree shaking since none of the classes are instantiated in Dart.
There's also a Baz.dart, and I would like to have a different build for compiling Foo.dart and Baz.dart into a single file (though this is less important, as I can accomplish this would separate projects and some symlinking).
Thanks!
This use case (build a JavaScript library with Dart) isn't supported yet.
The reworked js-interop package is supposed to allow to do that but I don't know about it's current state.
I am curious to know if its possible to have Asynchronous module definition with Angular.dart (or dart in general), if yes, then please share a sample code for such a single page application.
AMD is made largely irrelevant by the fact that Dart comes with a complete module system that is built into the language. That is the purpose of the import statement. Dart files are dynamically loaded in Dartium. If you are using the darttojs transpiler, it will create a single large file. The solution to this is to use use the DeferredLibrary class which will cause darttojs to create separate javascript files for each annotated import
See Seth Ladd's blog post for more details.
I'm trying to package the Mac version of an open source application that I didn't write (I'm not much of a coder). I'm using py2app 0.6.4. The application builds on my system properly, but I'm unsure of what to list for the includes in the setup.py file.
The dependencies include qt4, PyQt, matplotlib, cherrypy, and sip.
When I looked at this article on handling PyQt applications, I noticed the dependencies were not listed simply as PyQt but rather *PyQt4._qt* etc. How can I determine what to insert in the includes statement from the code of the application?
When py2app runs, it's going to look at each of your scripts, automatically grabbing any modules or packages imported by your scripts. In many cases, this will suffice and you won't need to list anything in the includes variable. Some packages have extra files such as data files that aren't used by the import statement, but must be present for the package to run correctly. Then you need to explicitly include it so py2app will grab it as well. Try to use your app; if you get an error that some module or file isn't found then worry about putting it in the includes variable.