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Notify the child when there is onClick event in parent

I have a parent component that holds a string as a state. This string is composed with help from other child components.
Then the parent sends this string to a DisplayText component that displays it. However in the DisplayText component there is an internal state for that string and thus the user can change it however they like, and the result
const [myString, setMyString] = React.useState<string>('');
React.useEffect(() => {
// do some stuff with the string and save it
setMyString(string);
}, [...]);
<Textarea
value={myString}
onChange={(value) => setMyString(value)}
/>
(This is just basic React.) I would like to add a button in the parent component that forces the child to override any changes the user has made, and re-render the text coming from the parent. This happens naturally when the state in the parent changes, but how can you simulate the same effect when a button in the parent is clicked?
I could solve this by moving the internal state of editing the text from the child to the parent, so clicking the button can control that, but is there another way without doing so? Because the edited text shouldn't concern the parent. The second solution I thought of would be to force a re-render of the parent but the ways to do so are hacky (changing a dummy state).
Is there a simple solution to this?

Composing a string in multiple child components seems like a bad approach to me. But if you really need or want to do it that way, then adding a button in the partent component, that overwrites myString, should work. The props that refer to this value will update automatically. Just remove the internal state of the children, to have a 'single source of truth'.

That sounds like bad practice to me.
You should:
lift state up to parent and have a default value which is saved. Clicking the button should just reset to the default value.
If you need to change the parent state from one or more childs, you should pass down a setter function which sets the state in the parent.

How Do I Target A Specific Node In React Component and Have Independent Behavior When Component is Reused?

I am trying to target a specific node in my react reusable component and perform an operation on it. But I want to be able to do same thing several times independently because I will be returning this my reusable component several times on the same page on my App.js. How do I target that div node uniquely?
Here is my situation:
I created a react class component (I am not using function component for this project). This component contains two divs and a button. The first div is a red box. Under it is the second div which is empty with the class "result". There is also a button. When I click this button, the package Html2Canvas will convert the first div into an image and append it to the second div.
Now from the Html2Canvas documentation, they only specified how to append the generated canvas to the body of the DOM:
html2canvas(document.querySelector("#capture")).then(canvas => {
document.body.appendChild(canvas)
});
Since I needed to append to that empty second div, I did:
html2canvas(document.querySelector("#capture")).then(canvas => {
document.queryselector('.result').appendChild(canvas)
});
This would have been fine if I am just using this component once on a page, but in my App.js, I am actually returning this my component multiple times, so what now happens is that each time I click that button, it targets only the first instance of the empty whereas what I need is that each occurrence of my component should behave like the first one independently.
Yes I have tried using CreateRef() to target the current occurrence oof the empty dive but it does not work. It sees the ref as undefined when I call it inside the Html2Caanvas function. But outside of it, it is defined. Ok I tried creating the ref inside, still gave an error of undefined.
I understand that this whole thing I have written may be somewhat vague, so here is a CodeSandBox example of what I want.
When you open it and click on the first "Finish" button, you will see that the red box gets converted to an image, and the image is added under the red box, that is, it is appended to the div with class "result". But when you click on the second "Finish" button, instead of the generated image of the blue box coming under the blue box div, it goes under or beside the previous image. The expected behavior is for it to appear under the blue box. And if I replicate that component "ReUsable" as many times as I want in the App.js, the same behavior is expected. Independence.
I know this is a lot. I look forward to and appreciate your solutions.

First, the ref approach was great (the one you commented out), only that you were referencing the containerRef and not the screenshotRef.
the main issue came from the callback function passed to html2canvas, even though you called bind on handleFinish, binding "this" context to the current class context, the execution context of "this" in the callback is undefined because you used a regular function and regular function always refers to the context of the function being called(html2canvas).
arrow functions on the other hand treat the "this" keyword differently. They don't define their own context.
kindly update your handleFinish method to this
handleFinish(event) {
html2canvas(this.containerRef.current, 1).then((canvas) =>{
this.screenshotRef.current.append(canvas);
// document.querySelector(".result").append(canvas);
});
}

React/JSX - how to code an editable input with initial content provided via props that only updates its parent when submitted?

All the examples I have found that keep local state can't provide an initial value for the input. In my case a parent component retrieves field from a server and passes these to my input form where the fields shall be editable. But I don't want to pass each change back up the hierarchy if I can avoid it, rather only when the form is submitted (either via button or by pressing enter)
Update: the usage is as follows. Imagine a todo list. The top level holds the list and the detail component. When I click at the list the detail should update to show the selected todo text. That text should be editable.
So as far the the detail component goes the initial state of the input is the text from the list that gets passed down in props. It needs to change when a different todo in the list is selected. On the other hand I should be able to edit it and when submit triggered that todo text should be passed back up via a callback prop.
So I have to keep local state to collect the input, but I want that state to be initialized with the existing todo text from the list. If I use the Facebook example of an uncontrolled form, I find the edited text remains displayed when I switch to a different todo in the list. Maybe I'm doing it wrong or is it a conceptual problem? Using controlled input initializing the state in the constructor doesn't work either because the constructor only gets called once (not on each re-render)!

I solved the problem by using the lifecycle method componentWillReceiveProps(nextprops) where I can set the state to the new props. This method gets called each time a re-render becomes necessary - in my case because the parent changes the childs props.
See https://facebook.github.io/react/docs/react-component.html#componentwillreceiveprops

You can set the initial state based on the property passed in from the parent, then edit that state in the component before submitting with the form submission

How to hide/show adf component automatically

Hi I want to hide an adf component automatically.I have a selectOneChoice that contain some number (from 1 to 12).
Example when I select 2, it show's two field automatically without clicking any button..
i used this function to hide a declared componenet but just when i click a button..
function enableField(actionEvent) {
var nameInputText = actionEvent.getSource().findComponent("soc1");
nameInputText.setProperty("visible", true);
actionEvent.cancel();
}
i set the componement "soc1" visible = true than through the javascript function i change it..
SO the probleme here is how to read the number from the selectonechoise and how to set the component visible directly without clicking any button.

Actually Rendered won't do what you want. You want to use Visible property instead. Rendered causes the actual markup for the component not to be rendered on the page, so a Partial Refresh will not cause it to appear. Rendered is reserved, usually, to hide items that are secure. We set rendered property to false on the item(s), but then refresh the parent containing component - usually a layout manager - then it works. So either refresh the layout manager that contains the item or use Visible. I demonstrated this exact use case last week in class and it works as described.

Basicaly, you don't need javascript solution or any programming to achieve this.
You should set attributes rendered(this way component won't be rendered at the page at all) and partialTriggers that points to selectOneChoice component for components you want to show or hide. Also you have to set autoSubmit="true" for your selectOneChoice component.
<af:selectOneChoice id="soc1" autoSubmit="true" .../>
<af:panelGroupLayout id="plg1" partialTriggers="soc1">
<af:outputText id="ot1" rendered="#{bindings.lov.inputValue le 1}" inputValue="text1"/>
</af:panelGroupLayout>
Note: its not working code, just a sample
It will work following way, on valueChange event at selectOneChoice component value is submitted and partialRefresh fires for components that have it in partialTriggers specified. And rendered attribute will either render or remove component depending on it's EL expression. Components that should be managed wrapped into another component to make sure PPR reach it when they ain't rendered.

How to programmatically add components or views inside other components/views in ember js

I have a component say {{component-1}} which gets called many times and creates a custom-texbox container and label as many times as it gets called.
Now whenever a user writes something in it a suggestion box should appear below it. Since the suggestion box can be reused everywhere i dont want to have a separate suggestion box for each {{component-1}}, rather i want to have another component called {{suggestion-box}} that gets inserted inside component-1 i.e. the textbox container.
I dont want {{suggestion-box}} to be inside dom at all since it is needed only when somebody types in it. I want to add/insert it into {{component-1}} when someone types. Instead of a component i even tried to use a view
Here are the different things i have tried and failed
Note:
suggestionBox is the component
textbox-container is an element inside {{component-1}}
Inside {{component-1}}this.$().find(".textbox-container").append(this.suggestionBox );where this.suggestionBox = suggestionBoxComponent.create(); I have event tried suggestionBoxView.create();It gives me the error that i one view cant be inserted into another and i need to use containerView
var tmp = Ember.Handlebars.compile('<div class=".suggestionBox"></div>');this.$().find('.textbox-container').append(tmp());I get the error called
Uncaught TypeError: Cannot read property 'push' of undefined
I even tried to use view instead of component i.e. make suggestionBox a view but then again i cannot insert one view inside another
I have tried a lot more things.
Few points:
I dont want alternate solutions of how textbox and suggestion box could be created
How to pass information from a component or a a template to a view? Say i do {{view "suggestion-box"}} inside component-1 template, how do i pass values to it? Say for components we pass in the context like this {{component1 sampleVar1=val1 sampleVar2=val2}}
i Want to know how to programmatically add a component or a view and if it is a view how to pass the data to it?
I dont want to use container-view since it will cause more complexities, however if your solution allows me to pass value from {{component-1}} to container-view and inturn pass it to corresponding childView1 and childView2 then that solution is acceptable
Just an update:
I even tried to use a view container inside the {{component-1}}
I also tried to use view block inside {{component-1}} i.e.
{{#view "view-name"}}
----earlier component elements here-----
{{/view}}
In both the above points "view-name" is a ContainerView which is getting inserted properly but the component element are not getting inserted

This can be achieved with a ContainerView and the viewName attribute. The component or view can access the ContainerView or any other view that is part of a template through its assigned viewName.
Example,
hbs
{{view Ember.ContainerView viewName="my-menu-container"}}
js - then from the component or view
this.get("my-menu-container").pushObject(suggestionBoxViewOrComponent);
http://emberjs.jsbin.com/yoyujeqi/1/edit
p.s. the context of the example is not relevant to the suggestion box, sorry about that, as it has been extracted from another answer related to adding a menu view dynamically.