What's the difference between Text and new Text in dart?
Also suitable for Container and all other widgets.
As of Dart 2, you don't need to use new keyword to create a new instance. So basically, if you're developing in Flutter and Dart 2+, Text and new Text is the same.
Take a look at the Dart documentation about constructors.
In Dart 2 new is an optional keyword. So Text and new Text is basically the same thing.
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I am new with declarative UI in vaadin,
how to get the java instance like TextField that was declare in xml ?
I want to set value to it. not found how to get it.
With the #Id annotation
#Id("my-textfield")
private TextField myTextfield;
Please read the documentation:
https://vaadin.com/docs/latest/flow/templates/components
For Jmix, you can directly inject the field in screen controllers by using #Autowired annotation.
You can find examples here: https://demo.jmix.io/sampler/#main/3/sample?id=textfield-trim
Notice: the injects property name should be the same as id property in the XML.
btw, you can ask Jmix questions on https://forum.jmix.io
This question already has answers here:
Do you need to use the "new" keyword in Dart?
(3 answers)
Closed 3 years ago.
When, for example, I want to create a button with the text "button" in it I create a RaisedButton with a Text widget as its child. Wheter or not I use the 'new' keyword before this Text does not seem to make a difference in the end result of the button. Therefore I was wondering in what situation the new keyword would be necessary when making use of the regular widget like RaisedButton and Text.
I am, off course, familiar with the 'new' keyword and its uses to create a new object but in the situation that I just described I do not understand how the keyword makes a difference and wheter or not I should use it.
The new keyword is totally optional from Dart 2.0. It's not mandatory to use it.
I have an Objective C++ program used to handle the setup of our different applications. Is there a way to use preprocessor defines to create text to be substituted in the strings used by NSTextFieldCell, NSButtonCell?
FOR EXAMPLE, instead of have an NSTextField that says "Options for setting up Foo", there would be a preprocessor macro (GCC_PREPROCESSOR_DEFINITIONS):
MY_PROGRAM_NAME=Bar
and then the text for NSTextField would be:
"Options for setting up $(MY_PROGRAM_NAME)"
Which would then have the desired result: "Options for setting up Bar"
NOTE 1: obviously, I could do the substitution programmatically in code.
Note 2: this is for Xcode 7, so perhaps there isn't a feature like this?
In a word, no. The Xcode nib compiler doesn't perform any kind of variable substitution and—once encoded—all archived property values are static.
However, if this is a "thing" for you application, and there aren't too many view classes involved (say, just NSTextField), it wouldn't be hard to roll your own solution.
I'd consider this approach:
Concoct a simple-to-substitute syntax, a la "Some string {VAR_NAME}".
Define your variables as key/value pairs in a dictionary. Store the
dictionary as an XML file / dictionary in the app bundle.
At app startup, load the dictionary and make it public by putting it in
a global variable or adding it to -[NSUserDefaults registerDefaults:]
Subclass NSTextField (as an example). Override either
-initWithCoder: or -awakeFromNib. In the override, get the string
value of the view object, scan it for substitutions using the public
variable dictionary, and update the string property as appropriate.
In IB, change the class of any NSTextField that needs this feature to
your custom subclass.
Another possible approach would be to have multiple targets in your project and a separate Localizable.strings file for each of these. This of course assumes, that you use Localizable.strings, even if you may support only one language.
I know how to use live bindings on a form to bind one property to another property using an expression. For instance, binding a TLabel's Caption to a TEdit's text property.
I know how to create new expressions using IScope, TNestedScope, TDictionaryScope, etc. I can add my own classes and call them as scripted expressions.
What I don't know is how to take my new expression scope and make it available to the TBindExpressions in my TBindingList for use on a form when I'm doing things described in the first paragraph.
Anyone know how to do this? I've investigated, and I can't find a way to add an IScope reference to the binding expressions available to TBindingList and its sub-components.
I am interested in using the Builder pattern for declaratively creating UI with Rikulo. Is there a way to do so? Does the Dart syntax support a similar mechanism?
For example,
div(
label(value:"OK")
);
Yes, it is possible. First, you have to define global functions for div, label and other ui objects. For example,
TextView textView([String text, String html])
=> html != null ? new TextView.html(html): new TextView(text);
It could be an excellent addon.