How to improve performance while using dynamic components in vue? - vue.js

Context:
Currently, I am working on a complex editor application which uses vuex state, vuetify's expansion panel and vue's dynamic component. Each dynamic component uses data which is accepted as props and has its own nested components.
Problem:
The issue with this approach is as the app deals with the large, nested state, the add operation in the UI slows down and makes the UI unusable.
Note:
In the example, I have added 1000 objects just to replicate the issue. Unfortunately cannot use pagination here.
Is there any other way to approach this problem to improve the performance, any suggestions would be helpful.
Issue:
Codesandbox - Demo
Codesandbox - Edit

You are using index as your key and at the same time adding new item to the beginning of the array using unshift - which means every time the new item is added, all components needs to be rerendered. Use :key="item.name" instead and you will see huge speed improvement on adding new items...
Initial render is another problem - if the pagination is not an option, you can look at some virtual list solutions which do render only part of the list visible and make scrolling effective by reusing existing components. One example is vue-virtual-scroller. Vuetify itself has it's own implementation but I'm not sure how well it will work with expansion panel considering this note in the documentation:
We are in the process of integrating the v-virtual-scroll component into existing features and components. If you are interested in helping, please reach out to John Leider in the Discord Community.
(Also it seems you are using really old version of Vuetify...)

Related

Vue3 computed property in parent child component structure not working

After trying to find solution to this issue for hours on various forums i am posting this here.
So i have two components. 1) App and 2) Todo. Both renderes a list and i can complete items so there will be two lists one for incomplete items and one for complete items. you can click on item and it will be gone to complete items list.
So in my example you can see i am using same component but with two diffreent ways to give data to component. one using API and one using native js Data. in both cases it renderes but with api i can click on list item and it will be gone to completed list but with javascript array example it doesn't work. i am completely amazed with this because component is same. how it can affect like that.
many answer here do tell me that computed properties are not reactive as they are cached but what’s the solution to that ? i can put data variable but then the first case of api will not work because time it takes to fetch it. so please help me with this one.
complete code at sfc playground
You have reactivity issues the computed property probably expects that value to be constant because you provide a non-reactive array from the parent.
I think you have 2 options here:
you either provide a reactive prop from parent
or you set a local data attribute in the child-component so that vue will know that it can change
Your fiddle didn't work for me so I copied your code to codesandbox, I have both examples there but commented out the first solution, there you basically simply add the array to the data object and reference that in the code.
Second solution you can add a mounted hook to define reactiveAssignments to your data in the child component this way it will have the same reference so that's why it would work that way.
I think the first solution is simpler, but it is really up to which one you prefer.
You can check the solutions here in my codesanbox
A better approach could be though by setting up component events instead of v-models in the child you should use it in the parent because this way you are directly modifying the props. You can read more about this here: https://vuejs.org/guide/components/events.html#usage-with-v-model

Is it necessary to create a ui component(s) for a single call in one page?

I am about to create a Vue.js project and i use the smart/dumb pattern for my ui components. In my dumb components I have already the input, buttons and etc..., but in my smart components I am curios if it is really necessary to create a component if i will use that only in one page. For example. login-form component, then i will use that only in login page. So, ⤵️
My first question, is it really necessary to create a component for that ?
Second question, and when will i gonna create a smart components?
Moving code to another components makes code of initial component more readable. Even if you are going to use that new components only once.
Usually smart components - are pages that fetch or simply share some data to its children.

List of same components with same functions - code bloat?

I'm using Vue and I wonder if I have a list of components (50 button with the very same function within each one of them) - will Vue recognize it as a repetetive code and reduce to one function that all those 50 button will use or each one will compile it's own function while bundling?
will Vue recognize it as a repetetive code and reduce to one..
No. Vue will not scan your code for similar code and try to optimize it.
However, when Vue is updating a list of elements rendered with v-for, by default it uses an “in-place patch” strategy. If the order of the data items has changed, instead of moving the DOM elements to match the order of the items, Vue will patch each element in-place and make sure it reflects what should be rendered at that particular index.
Maybe this is what you are confused with? This is not the same as the question you are asking, but the closest thing vue would do "magically".
If you have 50 similar buttons, I would advice you to rather take advantage of props, slots and slot scopes to only have one button component that you can tweek in place where you need them to be different. 50 alike buttons sounds like a bad pattern.

Nested components in Vue.js 2

I'm being using Vue.js for some months and it's have been reminding the webforms paradigm, that you used components to make a website or webapp, but with Vue.js it's a pleasure to create such things and not a whole nightmare it was with webforms.
Well, my question is if it's possible making nested components just to define some behavior on it's parent on a markup-way. Example:
<grid prop1="somevalue" prop2="somevalue">
<grid-column prop1="somevalue" prop2="somevalue">
<filter-options prop1="somevalue" prop2="somevalue">
</filter-options>
</grid-column>
</grid>
So, a particular grid component have column and the column hava a filter options.
Don't want to depend stricty to the javascript code.
Thanks in advance
EDIT: Just to add that the childs-component must not have a template. They are just to pass some props to the parent.
To answer your question
if it's possible making nested components just to define some behavior on it's parent on a markup-way
And to keep in mind your request:
Don't want to depend strictly to the JavaScript code.
The answer is no, it is not possible. Components underneath the parent can only push (emit) data to the parent after the DOM loads. So you would need to push a value that would trigger some JavaScript if you wanted to alter the html. Using JavaScript would be the only method though.
To achieve what you are asking I think it makes a lot more sense to use props on the parent component. You have a lot more flexibility and you can make it very versatile.

cache view in vue.js

I have started to build apps with vuejs recently and have one small issue that I can't get around:
I am using vue-router to jump between pages and lets say I have a huge list where additional items may be injected with ajax, user has to scroll, he click on item, see the details (is in new route) and when gets back list is reinitialized and has to scroll again to be at the point he was previously. Do I have some possibility to keep the state of given component (and view like scroll position) while using vue-router or do I have to keep some cache-instance in main app component and then map it on init?
Thank you.
Essentially, the issue is that your component stores state internally. Navigating away clears the state. There are two ways I see this could be handled.
1) (quickfix) instead of redirecting use another way of displaying the item details (modal, or expand come to mind). This way the state of the component is not lost
2) (the "proper way") store the state. Inevitably, you'll come up against this sooner or later and the best way to deal with storing a state is vuex. https://vuex.vuejs.org/en/intro.html Initially, this will require a bit of learning and add some complexity, but it is a worthwhile investment