how to remove this.$set when migration from vue2 to vue3 - vue.js

I am doing migration from vue2 to vue3 and I need to remove $set as required.
So for example, in my application my code is like this in vue2:
this.$set(..., ..., null);
So to delete it should I use additional package like tiny-emitter and apply it like this?
emitter.set(..., ..., null);
How can I remove $set from my application for vue3?

You don't need vue Set anymore because reactivity is now work fine in Vue3.
So to replace this.$set for an array you can juste do that:
// Old vue2 -> this.$set(array, index, null);
this.array[index] = null
So in each use you have, you just need to do the basic JS you need, and do not care about reactivity issue :).

Related

Create component in template from data variable

I have multiple components that take same props. I want to use those components in template in such a way that I don't use multiple if-else statements in my template. I created an object in my data and paired my components with string keys. Is there a way to call those components in template with that object ? My data object looks something like this:
componentMap:{
"testComponent1":TestComponent1,
"testComponent2":TestComponent2,
},
For example, if I give "testComponent1" as key, then in template it should use TestComponent.
Use the component tag.
<component :is="componentMap['testComponent1']"></component>
See the Docs

"v-on with no argument expects an object value" facing this error in quasar selector when focus into the field

here is my code, options array updated in created hook based on api response and response of api is array of object and v-model value is also updated in created hook. this selector is of input type and also filter the data based on input type from options array.
hope so this chunk of code is enough to explain.
<q-select
ref="registeredCountry"
for="registeredCountry"
color="olab-brand-blue"
v-model="registeredAddress.country"
use-input
fill-input
hide-selected
:options="countryOptions"
#filter="filterCountryList"
emit-value
option-label="countryName"
option-value="countryName"
#update:model-value="resetStateAndCityFields('registeredAddress')"
map-options
>
</q-select>
I got exactly the same Vue warning with one of my q-selects, after migrating it (unchanged) from Vue 2/Quasar 1 to Vue 3/Quasar 2. The same q-select code worked without warnings on the older levels. The warning is very unspecific from a Quasar point of view.
However, I found a hint on https://github.com/quasarframework/quasar/issues/8898 to eliminate this warning, which helped to resolve the issue in my case.
The reason for the warning was in my case due to the use of q-chips with q-items for the options in the q-select. Those q-items for the q-select options used "v-on='scope.itemEvents'", together with "v-bind='scope.itemProps'", which was the recommended combination in Quasar 1/Vue 2.
In Quasar 2/Vue 3 the "v-on='scope.itemEvents' is no longer necessary (if used, it causes this Vue warning). Just search for all "v-on='scope.itemEvents'" in your template code, then drop (i.e. delete) those "v-on=...", but keep the "v-bind=...".
This eliminates the above Vue warnings (which otherwise come up for every selectable option in your q-select).

Vue - where should I declare element variable to use in any lifecycle or method?

I'm new to Vue and wondering where I would declare something like:
const qualityDropdown = document.getElementById("qualityDropdown");
in a single place so I can use it in any lifecycle and / or method in a component without having to re-declare it in every place. Part of the issue being that sometimes elements are created after an axios call and aren't immediately present.
Would this go in data(){return{}} or computed(){}?
You can define its ref as follows:
<select ref="myDropDown" id="qualityDropdown"></select>
And call it using
this.$refs.myDropDown

how to solve vue short if in v-model?

I need to do a shortif in a v-model, but eslint gives the folowing problem:
[vue/valid-v-model] 'v-model' directives require the attribute value
which is valid as LHS.eslint-plugin-vue
so the code works. but its not the way it needs to work.
this is the code i have now
<v-text-field
v-show="field.type == 'String'"
v-model="_isMultiple(content_data[tabindex]) && subitem != null ? content_data[tabindex][subitem][field.name]
: content_data[tabindex][field.name]"
:label="field.name"
:counter="field.counter"
max-width="100px"
/>
So this code needs a little explanation to it.
I try to build this as an dynamic module. If I get an array back from my json response it needs to v-model the subitem. If I get an object back from the response it just needs to v-model that object.
The data (content_data[tabindex]) + field do i get from a v-for loop and other loops in my vue html
so I think its not an option to do a computed prop because
I can't get in the right data.
_isMultiple function code:
_isMultiple(content_data) {
return Array.isArray(content_data)
}
any solution for this?
Maybe you should not use v-model, but build it on your own with value binding and event listening.
v-model is only a shorthand: https://v2.vuejs.org/v2/guide/forms.html.
By implementing it on your own you can use a method to set the values and a computed property to get it.

VueJS Component Input Sync

I want to create components which have input which two-way bind to the local scope of the component.
Without a component, I would create a new Vue instance and then set my data to what I need. Then using v-model, bind an input to that data and it can be manipulated from the input.
However, converting the same code to a component, I cannot for the life of me get any input in a component to bind to its data. I have tried props, :data.sync, data attributes but no matter what I have tried, the input within a component does nothing.
I have created a JSFiddle to illustrate this:
https://fiddle.jshell.net/f0pdmLhy/2/
What I would like to happen is the input in the component to two way bind to the err variable, just like the non component version underneath.
How would I accomplish this?
I basically want to create components that I can instansiate with ajax data and then populate the inputs. The inputs could then update the data and I can use a save method to send the data to the server. Can this even be done using components?
So there are a couple of things:
The external resource you were using was somehow faulty. I've used
jsfiddle default Vue instance and it works fine.
When you declare a component, you should not define the data as an object, but as a function returning an object. Read here: https://vuejs.org/guide/components.html#Component-Option-Caveats
A working example here: https://fiddle.jshell.net/by4csn1b/1/
Yes, with components, the reactivity can be accomplished just like with an instance.
One catch with components, is that data must be a function that returns an object.
Also, to maintain the two way binding, use v-model in your input.
Vue.component('ii', {
template: '<span>{{err}}</span><input type="text" v-model="err"><hr>',
data: function () {
return {
err: 123
}
}
})
Fiddle: https://fiddle.jshell.net/f0pdmLhy/25/