I'm trying to recreate the doughnut to pie change in behavior as seen here:
https://www.chartjs.org/samples/latest/scriptable/pie.html
I'm using VueJS version of Chart JS and after recreating this it seems to not be reactive at all.
Here is the method that I use to change the chart to the other one:
togglePieDoughnut() {
this.options.cutoutPercentage = 50;
}
As you can see it does not work as intended, even tough I used reactiveprop mixin.
EDIT: To be precise I want to recreate the chart update behaviour as seen in the example on chartjs.org website. I do not want to rerender the chart, rather update it so the transition remains smooth.
Seems like the issue is the template isn't reacting to the data changes. Best way to force template re-render is to bind a key, for our example, we are changing this value, the template will update when its changed:
:key="options.cutoutPercentage"
Codepen example:
https://codesandbox.io/s/vue-chartjs-demo-t8vxu?file=/src/App.vue
What if we add a watch to the options variable and rerender the chart when it happens?
watch: {
options: function() {
this._chart.destroy();
this.renderChart(this.donut, this.options);
}
}
When you look at the code of Piechart.vue, it seems that it only render one time on mounted. Thats why when changing the options, it not gonna reflected in the chart because there is no function to rerender.
The only way is you have to remove the old pie chart and create a new one when options changed. There's a lot of way to do the force re-render, but still the cleanest way is as procoib said, attach a key to it.
When using object as props and update one property in it, the reactivity system will not trigger the change, because the object is the same and only one property updated. Thus, the child component will not get the updated value.
What can you do is to recreated the object with the updated property. See below code:
this.options = Object.assign({}, this.options, { cutoutPercentage: 50 });
And in the child component, use watcher re-render the chart
watch: {
options(newVal) {
}
}
Related
I'm trying to create a simple component whose focus is to display an element in an array, but I'm having issues with Vue's philosophy.
As you may know, if a mutation on a prop is triggered, Vue goes crazy because it doesn't want you to update the value of a prop. You should probably use a store, or emit an event.
The issue is: that since I'm adding functionalities to my codebase (for instance the possibility to start again when I reach the last element of the array), it would be wrong to have an upper component be responsible for this management, as it would be wrong to ask an upper component to change their variable, given that my component is supposed to manage the array, so an emit would be a bad solution.
In the same way, given that I'm making a generic component that can be used multiple times on a page, it would be incorrect to bind it to a store.
EDIT: the reason why the prop needs to be updated is that the component is basically acting as a <select>
Am I missing an obvious way to set this up?
To give an example of my end goal, I'm aiming for a component looking like the one in the picture below, and I think a 2 way bind like in v-model would be more appropriate than having to set an #change just to say to update the value of the passed prop.
If you have a prop the correct way to update the value is with a sync, as in the following example
Parent:
<my-component :title.sync="myTitle"></my-component>
Child:
this.$emit("update:title", this.newValue)
Here is a very good article talking about the sync method.
By the other hand you can alter a Vuex state variable by calling a Vuex mutation when you change the value:
computed: {
title: {
// getter
get() {
return this.$store.state.title
},
// setter
set(newValue) {
this.setTitle(newValue) // Requires mutation import, see the methods section.
// Or without import:
this.$store.commit('setTitle', newValue);
}
}
},
methods: {
...mapMutations("global", ["setTitle"]) // It is important to import the mutation called in the computed section
}
In this StackOverflow question they talk about changing state from computed hook in Vue. I hope it works for you.
I have two components in mu app.vue and i will send data from app.vue to my first component(filter component) at the time of page load.
Now based on the user actions in the displayed data in the second component i need to pass new vales back to the first component.
There i am using a and a . Consider one of the props i receive in the first component is "nselectedOption" and i do this in data: { return { selectedOption: this.nselectedOption }} to avoid mutation warning.
Now everytime i update the values for this component from second component, i am seeing changes in "nselectedOption" only and not in "selectedOption". Can you explain why is that ?
I need the updated value into a v-model of .
1. If i use "nselectedOption" it is updating the textbox but while editing the value throws error.
2. If i use "selectedOption" it is not updating the values in the textbox itself.
I have even tried using the computed values to return the value, it works but if i try to change values in other options in the filter component the already updated values displays null or nothing.
Please help me. Is this problem can be solved using State Management Concept or do i have to have a separate compoenent other than App.Vue to do all this so that it would act as a parent/child kinda thing or is there anyother way to overcome this.
Try using watcher. If you watch for nselectedOption, everytime it changes, the watcher will fire and bind the changed value to selectedOption.
props: ['nselectedOption'],
data: {
selectedOption
},
watch: {
nselectedOption: function (val) {
this.selectedOption = val
}
}
Also, if the prop you are watching is an object/array, consider using spread operator if you want to make a local copy to avoid mutation.
this.someObj = { ...someProp }
I am creating a tab component that loads its v-tab-item components dynamically, given an array of configuration objects that consist of tabName, id, and tabContent which is a resource location for the component. I have it successfully loading the components. However, they don't actually initialize (or run their created() methods) until I switch tabs. I just get empty tabs with the correct labels. Using the DOM inspector initially shows just <componentId></componentId>, and then when I switch tabs, those tags are replaced with all of the component's content.
How do I get the dynamic components to initialize as soon as they are loaded?
EDIT: I created a CodePen here:
https://codepen.io/sgarfio/project/editor/DKgQON
But as this is my first CodePen, I haven't yet figured out how to reference other files in the project (i.e. what to set tabContent to so that require.js can load them up). I'm seeing "Access is denied" in the console, which makes it sound like it found the files but isn't allowed to access them, which is weird because all the files belong to the same project. So my CodePen doesn't even work as well as my actual project. But maybe it will help someone understand what I'm trying to do.
Also, after poking around a bit more, I found this:
http://michaelnthiessen.com/force-re-render/
that says I should change the key on the component and that will force the component to re-render. I also found this:
https://v2.vuejs.org/v2/guide/components-dynamic-async.html
Which has a pretty good example of what I'm trying to do, but it doesn't force the async component to initialize in the first place. That's what I need the async components to do - they don't initialize until I switch tabs. In fact they don't even show up in the network calls. Vue is simply generating a placeholder for them.
I got it working! What I ended up doing was to emit an event from the code that loads the async components to indicate that that component was loaded. The listener for that event keeps a count of how many components have been loaded (it already knows how many there should be), and as soon as it receives the right number of these events, it changes the value of this.active (v-model value for the v-tabs component, which indicates which tab is currently active) to "0". I tried this because as I noted before, the async components were loading/rendering whenever I switched tabs. I also have prev/next buttons to set this.active, and today I noticed that if I used the "next" button instead of clicking on a tab, it would load the async components but not advance the tab. I had already figured out how to emit an event from the loading code, so all I had to do at that point was capture the number of loaded components and then manipulate this.active.
I might try to update my CodePen to reflect this, and if I do I'll come back and comment accordingly. For now, here's a sample of what I ended up with. I'm still adding things to make it more robust (e.g. in case the configuration object contains a non-existent component URL), but this is the basic gist of it.
created: function() {
this.$on("componentLoaded", () => {
this.numTabsInitialized++;
if(this.numTabsInitialized == this.numTabs) {
// All tabs loaded; update active to force them to load
this.active = "0";
}
})
},
methods: {
loadComponent: function(config) {
var id = config.id;
var compPath = config.tabContent;
var self = this;
require([compPath], function(comp) {
Vue.component(id, comp);
self.$emit("componentLoaded");
});
}
}
I've got a little problem with vuejs.
My state is basically something like this.
state: ()=>({
activeSide : "from",
}),
I want a component to be focused or blurred based on whether activeSide has the value activeSide set to "from" or not
my idea at the moment, doesn't seem to be very elegant, I basically created a computed property in my component,
focusSide(){
console.log("changed active side")
this.$store.state.activeSide
}
and then I set up a watch to see if that property changes.
watch:{
focusSide : function(newV,_){
console.log("changing focus")
newV=="from" ? this.$refs.fromArea.$el.focus() : this.$refs.fromArea.blur()
}
},
the problems here is that apart from the fact that the solution doesn't look elegant the watch doesn't work either, I've seen that focusSide is changing its value correctly (or at least the body of the method is executed), but the watcher is not executed, I have the feeling that since focusSide state is never used in my template, vuejs thinks that it's not necessary to react and change values, something like reactive frameworks where if the value is not observated then don't change (maybe I'm wrong)
what would be the ideal way for achieve this???
thank you
You need return value of computed properties focusSide, otherwise it will always return undefined
focusSide () {
console.log("changed active side")
return this.$store.state.activeSide
}
I’m trying to make a chart reactive to state change, I have some filters on a sidenav and a component which include chart.js component like this :
<tendance-chart slot="content" class="chart-wrapper" v-if="!loading" :labelsRepartitionTendance="labelsRepartitionTendance" :repartitionTendance="repartitionTendance"></tendance-chart>
That’s works perfecly, but I want to reload this chart when my filters change, how can I do that ?
When your filter changes before the function execution change loading to true and at the end change loading to false. This however is not good a good practice, basically your chart should listen for its data and re render itself every time something is changed.
vue-chartjs ships with two mixins the reactiveDataMixin and the reactivePropMixin.
Which are adding a watcher to chartData and re-rendering oder updating the chart, if the data changes. http://vue-chartjs.org/#/home?id=reactive-data
you must use watch and pass a setTimeout() again calling the function that handles the data.
watch: {
dataToObserve() {
setTimeout(() => {
this.functionThatHandlesData();
}, 1000);
}
},