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Prevent Vue.js re-rendering child components

I've got a complex component which does all its rendering in a render function. There are multiple parts to this, and different bits of the view get rendered - one of these things is a filter bar, showing the filters that have been applied.
What I'm noticing happening, is if I apply a filter which in turn presents this bar, it causes everything else to be fully re-rendered. This is causing a number of other issues and I need to try and stop it from happening.
I've never come across this issue when using normal templates as Vue seems to handle these very intelligently, but I have no idea how to tackle this. The only thing I can think of is setting a key on each thing I don't want re-rendered but not sure if this will a) solve the problem, and b) be possible for the content that is passed in through a slot
Has anyone else faced this issue, and if so how can it be solved?

I had a similar issue when using vuetify text inputs in a complex component which was causing the app to slow down drastically.
In my search I found this link which was specific to vuetify:
high performance impact when using a lot of v-text-field
then found out that this is actually a vue thing from this GitHub issue:
Component with slot re-renders even if the slot or component data has not changed
and there is plan to improve this in it is tracked here (vue 3 should resolve this issue):
Update slot content without re-rendering rest of component
so after reading through all these I found some workarounds that helped me a lot to boost the performance of my app, I hope these will help you as well:
divide that complex component into smaller ones specially when there is some bit of code that changes data that bounds to template causing re-rendering (put them in their own component)
I moved all data layer control to the vuex store, instead of using v-model every where and passing data as events and props, all the data is updating in the store through an action and read from the store through a getter. (from data I mean somethings that is being looped in the template in a v-for, API results, and so on... all of them is being set, updated and read through the store. my components still have the data object but only for the things related to the style and template control like a boolean to control a modal or an imported icon which is used in the template and alikes)
lastly I wrote a function called lazyCaller which its job is to update the values in the store with a delay (when immediate data update isn't necessary) to avoid rapid updates comping from something like a text input (with out this every key stroke trigger the value update action)

Angular, Loop through already created components on the DOM

I'm pretty new to angular, but I have managed to get most of the concepts down. However, I can't seem to figure out how I should go about solving my issue.
I have one component, that has other components as its children. I want to be able to loop through the child components, and add data to them separately, either before they are rendered, or after they are rendered.
The master component is an HTML version of a government form, and I have scattered throughout it a simple component that is supposed to display text from a database relevant to the field it is in.
If I was using something like jQuery, I would just attach an id to each component, and loop through them, adding data if the component id matches the key of the JSON object.
Is there any standard way to do something like this with angular?

You'd be better off "binding" any information you'd like to provide to your child components instead of implementing a vanilla/jQuery solution that involves querying the DOM and then manually manipulating the DOM.
Take a look at property-binding and two-way binding.
Here's a quick example:
<my-child-component [someProperty]="myValue"></my-child-component>
<my-menu-component [menu]="menuData"></my-menu-component>

You probably should rethink the way you are trying to do it, when you start with Angular you need to leave a lot of concept that you learnt in jQuery behind.
We don't manipulate the DOM directly in Angular, we manipulate the data that is bound to the template and that binding is what updates the DOM.
Tom added an answer as I was typing, he is saying what I was going to.

The angular way to achieve what you want is to use one-way data binding. Check out the example in the documentation.
In the example they have a child component in the template html of the app.
<bank-account bankName="RBC" account-id="4747"></bank-account>
You can one-way bind data by referencing a public property on the parent and using the square bracket syntax to indicate one-way binding like so:
<bank-account [bankName]="somePropertyOnTheParent" [account-id]="someOtherPropertyOnTheParent"></bank-account>

Call method from sibling component using ReactJS

I have one ReactJS App which I reduced to the minimum as possible on the diagram below:
Side note: On this App I use Redux to manage state changes.
This App contains:
Component: UploadScreen with an image holder and a button. When that button is clicked, the user gets displayed a Popup Window which let him to pick an image from his device file system. Then that image is displayed on the image holder.
Component: AuxWidget which is a totally different component (needs to be separate) which also contains a button that when it is clicked it should popup the Select File window. I was thinking in something like triggering the click event of the first button.
Any idea on how to achieve that?
First I though about using Redux but I think that's not a too good idea because even though you can send messages with it from one component to another, that causes a render update and I don't want that.
Also, I was thinking on using jQuery but that's not the best approach when it comes to ReactJS.
Also, I thought about using the attribute: ref="foo" to get a reference to the other component but I think that's normally done when you want the interaction to be between parent and child components.
Also, I was thinking about EventEmmitter but I don't know if that's the best approach on this case (I'm using Redux to manage the state changes between components).

One of the best ways I can suggest using RxJS, you can create a Subject and pass it to your components. In one component you will need to subscribe to it and whenever you will call next on your subject from the second component, the other will be notified, so you can trigger open popup. You can even create your own implementation for this in case you don't want to add new library to your project.

The upload window could be triggered when a certain state in the app changes. The relevant state on the app could be changed from different places, like from AuxWidget and UploadScreen. That way they are not coupled with the upload window. They merely call a function that is passed to them and that function changes the state on the app and it will display the window.
If you have a shared component between two unrelated component I think it is best to lift that common component and let its state sit on a higher level.

If I understand things correctly, your primary concern is code-reuse as opposed to wanting to call a sibling method. Basically, you want a SelectFilePopup component that can be re-used (open/closed) cleanly. I think React Portals could be a good solution for this. I found a good example (https://github.com/Assortment/react-modal-component/blob/master/src/components/Modal.js) of how a Modal can be isolated into a component and be called anywhere in the codebase.
The usage of the Modal looks like this (copied and slightly modified from App.js in the github project above)
import Modal from './components/Modal';
<Modal><div>Click me to open Modal</div></Modal>
And the Modal component implementation (simplified)
render() {
return (
<Fragment>
<ModalTrigger
onOpen={this.onOpen}
/>
{isOpen &&
<ModalContent/>
}
</Fragment>
)
}
By default the Modal component shows a trigger (i.e button) when isOpen state is false. Once clicked, and isOpen switches to true, the ModalContent (i.e can be the FilePickerPopup) is dynamically created and attached to document body. You can check out the source code for more details. I think its a very clean solution to modals. So in your case, your code could end up looking something like this
UploadScreen.js
import FileSelectPopup from './components/FileSelectPopup';
<FileSelectPopup>{Upload Image}</FileSelectPopup>
AuxWidget.js
import FileSelectPopup from './components/FileSelectPopup';
<FileSelectPopup>{Upload Image or some other text}</FileSelectPopup>
So basically, AuxWidget doesn't even need to know about where the FileSelectPopup is located at. It's an independent component that can be called anywhere. The caveat is that the Modal implementation in the project I linked to is not a singleton (although it can be modified to be one). So if AuxWidget and UploadScreen are visible to the user at the same time, clicking both Upload Image buttons will create two instances of the Popup.

I would define the function in the parent component and pass it to both children as props

trigger save mutation from outside of multiple Apollo React components

In suite of React apps we're placing per view set of reusable apollo-backed form components with just one save button placed outside of the form components. On a save button clicked each component (with dirty state) should execute the mutation to persist changes.
I wonder about possible implementation options and I would like to avoid using refs.
The problem to be solved seems to be - how to call a method outside of the component - I tried to follow on this question Call child method from parent and while I'd rather do not use any React way of communication between components, one particular answer that looks promising to me is https://stackoverflow.com/a/45582558/3021889 - still I'd like to hear what options do I have.

Two components binding Vuejs

How would be perfect to organize data and interaction between two vuejs components? For example:
1) i have one component
item(v-for="item in items)
a {{item.name}}
2) and the second
card(v-for="item in items")
div.content
img {{item.photo}}
div {{item.desc}}
button Details
The main idea is when i click on list item i want to toggle the card with the same id, as list has. I use one file conponent management from vue webpack template.

A lot of folk seem to be trying to use Vue without a store. Could you be one of them? Perhaps because the store is not strictly part of Vue? Perhaps because the docs spend more time on parent-child communication, events etc (complicated) than on state management (simple)? Perhaps because OO has rotted our brains?
Vue wants to talk to a store. The whole point of bidirectional binding is to separate state from markup. The whole reason why this is such a genius idea is that many (most?) items of state have more than one representation on screen, like your items array. Your store, which can be as simple as a js object in window scope, should contain all your page state at a given moment. You should be able to copy-paste the store between pages, and be looking at the same thing on screen. The important qualities of a store are...
that there's only one of them.
that you 'normalize' your store so that an item of state is only stored once, and there are minimal dependencies between items of state.
Your items array should be in the store, and both components refer to this 'single source of truth'. If you're using other people's components, then you'll need to feed them some properties, but properties are for creating tunnels through Vue components to link leaf components with your store. Your items are your state, and state shouldn't generally live in Vue stuff. Does that help?