While experimenting with React Native and using States. I came against super(props). I searched here in the forum for a useful explaination, but I didn't find any.
Here is a look on the function, where I am using super and constructor...
1
I tried to delete props parameter in constructor, but it gave me an error. Then I tried to delete super(props), it gave me again an error. However, the code perfectly work, when I just used super() without parameter.
My conclusion is, in constructor i am saying we are using props and with super I am allowing an access over all props globally in code?
I am not really sure, correct me please If I am wrong.
I appreciate any comments with advises. Thanks in advance!
Edit:
I also added the rest of the code...For a clear undestanding..
2
I appreciate your help..
In React Native when using super(props) you can immediately access the props via this.props in the constructor while with only super() you can't.
In other methods like render however you can always utilize this.props.
Here is a complete examples of the explaination above:
https://stackoverflow.com/a/34995257/4293498
Related
I am almost done with my chat application in React native with Firebase. At the end, typing indicator needs to be updated with the app. Since I searched I don't get any proper reference code to implement it.
Is there any Reference/Sample code for typing indicator in react-native-gifted-chat?
Thanks in Advance!
Referencing https://github.com/FaridSafi/react-native-gifted-chat/issues/1565
Comment by shamilovtim // fixed typo
I'm using the latest version of the plugin. I simply have it set to a stateful variable coming from my Redux store. and my working example would simply be that. There's something you're doing wrong with how you manage state. I'd start out with make sure you're using this plugin inside of a function component because that's where I can confirm the typing indicator works. Not sure if it's broken in class components but those are legacy at this point so you might need to refactor.
import { useDispatch, useTrackedState } from 'reactive-react-redux';
const state = useTrackedState();
<GiftedChat
...
...
isTyping={state.isTyping}
/>
I would also make sure that your screen didn't mount with state already set to true. If you set it to true after it's already true your state hasn't changed and React isn't going to rerender a component. (e.g. your defaultValue should be false).
Hopefully this helps.
Hey i am trying to make my seed for cordova projects.
Everything was going good till this.$store in src/components/Main.vue is undefined i have no more
clues why cuz in other app it was working and never had this issue maybe someone more experianced with vue2 could help me out.
Cheers.
This is full code repo
edit:
If i pass $store from template or use this.$store in created store is working.
I was using arrow function in methods that was an issue.
I'm seeing ReactClass<*> in code for React-Navigation. I have two questions:
Why does ReactClass not need importing at the top of the file? Is it some kind of global constant in React Native?
What is the meaning of ReactClass<*>?
It is an existential type in Flow of a React Component.
In short, they're saying expect that tabBarComponent may or may not be there (note the question mark at the end of tabBarComponent?, and that it will be a React component class, with arguments of a type that flow will infer.
Flow is a tool for making JavaScript strongly typed.
I am writing a function to change the external links to my redirection link. I use pre_item_add hook, but I don't know how to update the submitted description with the new one. Does anyone know how to do it?
This is my idea:
function link_process($aItem){
$desc = $_POST['description'][$language_code];
Session::newInstance()->_setForm('description' , rewriteExternal($desc));
}
osc_add_hook('pre_item_add', 'link_process');
I made a similar change described here
Look for point 8. In my solution, but read all the answers to understand. Also there is a link in the solution to where I got this idea.
I'm trying to use react-native-camera#0.4.1 (with react-native#0.39.2) to create a QR code scanner. The relevant essentials of my render() method are:
<Camera
aspect={Camera.constants.Aspect.fill}
onBarCodeRead={(data) => console.log(data)}
barCodeTypes={['qr']}>
</Camera>
Without the barCodeTypes prop, everything works as expected. But once I include it, the view does not render, and I get the following error message:
*** -[AVCaptureMetadataOutput setMetadataObjectTypes:] Unsupported type found
- use -availableMetadataObjectTypes
I'm guessing that I just need to write my ['qr'] argument in some other and correct way, but I'm not able to find any information in the documentation.
Ok, so I found another post on Stack Overflow that helped me figure out the availableMetadataObjectTypes. So to fix my particular problem, I'll just be changing barCodeTypes={['qr']} to barCodeTypes={['org.iso.QRCode']}.
It should be changed to
barCodeTypes={[RNCamera.Constants.BarCodeType.qr]}