I am trying to pass a function into recaptcha to be used as a callback. I need to write:
data-callback="function"
In Vue how do I add the function reference?
I've tried:
data-callback="{{ this.submitFocus }}"
data-callback="this.submitFocus"
I'm using Vue 2
Recaptcha2 uses the data-callback string to call a globally available function.
From what I can see in the documentation, it doesn't look like there's a programmatic way to set this so you might have to use something like this
beforeMount () {
window.submitFocus = () => { // using arrow function to preserve "this"
this.submitFocus()
}
},
beforeDestroy () {
delete window.submitFocus
}
with
data-callback="submitFocus"
in your template. The attribute value just needs to match the function added to window.
data-callback is an html attribute of a DOM element, it's just a string. It does not know about the context of your object instance, ie. this.
So, you can't use this when setting the attribute for your ReCaptcha, it will only understand functions that can be called without this.
If you had a function defined as
function submitFocus(){ ... }
globally, you could get ReCaptcha to call it by setting data-callback to submitFocus without the reference to this.
data-callback="submitFocus"
Related
I'm using i18n for localization in my project but whenever i change the language, all page's translate is okay except grid header names! Its getting normal when i refresh the page.How can fix this situation without refresh ?
You can fix this by calling the refreshHeader function on the reader API.
try this :
this.gridApi.refreshHeader();
where the gridApi is the API object you get from the onGridReady event params.
EDIT, how to get the gridApi :
the gridApi u get from the params of the onGridReady method being called by the AgGrid component.
if you are using reactJs, an attribute named onGridReady in your agGrid component would accept that function.
onGridReady = params => {
this.gridApi = params.api
this.gridColumnApi = params.columnApi
...
}
If you are using headerName, maybe try to use computed() function to get ColDef
Ex:
const colDef = computed(() => // coldef here)
Help me solve with the problem please.
I am using jquery and jquery-ui to implement drag & drop in QASAR CLI.
But I ran into the fact that I cannot access the vue instance from jquery function events, since "this" no longer belongs to Vue, but refers to the selector element. Tell me how I can refer directly to the vue instance as it could be done in cdn version. There you could just give the name app = new Vue ... And then use it as app.data.variable
I believe this is more javascript question, than quasar/vue/jquery. You can easily set value of this by a bind function
let someFunction = function () {
console.log(this);
}
someFunction();
const obj = { 'test': 123 };
someFunction = someFunction.bind(obj);
someFunction();
Same thing applies to jquery function handlers. I guess you could pass your instance instead of obj
$(window).ready(function () {
console.log(this);
}.bind(obj));
My method in vue looks like this :
methods: {
setDate: async function () {
console.log(this.modal)
}
}
I want to change it to an arrow function. I tried like this :
methods: {
setDate: async () => {
console.log(this.modal)
}
}
There exist error like this :
Cannot read property 'modal' of undefined
How can I solve this problem?
use function directly like
methods: {
async setDate() {
console.log(this.modal)
}
}
You are facing this error because an arrow function wouldn't bind this to the vue instance for which you are defining the method. The same would happen if you were to define computed properties using an arrow function.
Don’t use arrow functions on an instance property or callback e.g.
vm.$watch('a', newVal => this.myMethod())
As arrow functions are bound to the parent context, this will not be the Vue instance as you’d expect and this.myMethod will be undefined.
You can read about it here.
This link https://michaelnthiessen.com/this-is-undefined/ says the following:
"An arrow function uses what is called lexical scoping. We'll get into this more in a bit, but it basically means that the arrow function takes this from it's context.
If you try to access this from inside of an arrow function that's on a Vue component, you'll get an error because this doesn't exist!
So in short, try to avoid using arrow functions on Vue components. It will save you a lot of headaches and confusion."
According to the page on event handling in the docs for Vue, when you use v-on like v-on:click="handler" the handler function will automatically get the original DOM event as the first argument. This code snippet is directly adapted from those docs.
new Vue({
// Vue config shortened for brevity
methods: {
handler(event) {
// `this` inside methods points to the Vue instance
alert('Hello ' + this.name + '!')
// `event` is the native DOM event
if (event) {
alert(event.target.tagName)
}
}
}
})
Why the heck can I still access event even if I omit it from the functions parameter list like this:
handler() {
console.log(event); // Still returns the native DOM object even though
// I don't explicitly define `event` anywhere
}
Shouldn't event be undefined if I don't add it as an argument to the function?
I believe that'll be the global window.event:
https://developer.mozilla.org/en-US/docs/Web/API/Window/event
Nothing to do with Vue, it's just an unfortunate coincidence that you happened to call it event.
Maybe the docs explains the reason to use event in the handler function as first argument:
You should avoid using this property in new code, and should instead use the Event passed into the event handler function.
https://developer.mozilla.org/en-US/docs/Web/API/Window/event
I am trying to make my Vue Component reusable but there is a part in it which requires to run a function on button click which I have defined in the parent component.
The component's button will always run a parent function and the parameter it passes is always the same (its only other property).
Right now I am passing 2 properties to the component: 1) an object and 2) the parent function reference, which requires the object from 1) as a parameter.
The Child-Component looks like this (stripped unnecessary code):
<button v-on:click="parentMethod(placement)">Analyze</button>
Vue.component('reporting-placement', {
props: ['placement', 'method'],
template: '#reporting-placement',
methods: {
parentMethod: function(placement) {
this.method(placement);
}
}
});
The parent is making use of the child like this:
<reporting-placement v-bind:placement="placement" v-bind:method="analyzePlacement"></reporting-placement>
methods: {
analyzePlacement: function(placement) {
this.active_placement = placement;
},
}
As you can see, the child has only one property, placement, and the callback reference. The placement must be put in as a parameter to the reference function from the parent.
But since the parent defines the parameters, the child shouldn't concern itself with what it needs to pass to the parent function. Instead I would prefer to already pass the parameter along in the parent.
So instead of
<reporting-placement v-bind:placement="placement" v-bind:method="analyzePlacement"></reporting-placement>
I would prefer
<reporting-placement v-bind:placement="placement" v-bind:method="analyzePlacement(placement)"></reporting-placement>
(including appropriate changes in the child).
But passing the parameter along does not work that way.
Is it possible (maybe in other syntax) to 'bind' the variable to the function reference so that it is automatically passed along when the callback is called?
Info: I don't get an error message if I write it down as above but the whole Vue screws up when I pass the parameter along to the component.
Hope the issue is clear :-) Thanks a lot!
By reading your proposal I've found out that you are overusing the props passing.
Your concern that child component should not have any knowledge about the way that the parent component uses the data is completely acceptable.
To achieve this you can use Vue's event broadcasting system instead of passing the method as props.
So your code will become something like this:
Vue.component('reporting-placement', {
props: ['placement', 'method'],
template: '#reporting-placement',
methods: {
parentMethod: function(placement) {
this.$emit('reporting-placement-change', placement)
}
}
});
And you can use it like this:
<reporting-placement v-bind:placement="placement" #reporting-placement-change="analyzePlacement($event)"></reporting-placement>
But if you need the data which is provided by the method from parent it's better to consider using a state management system (which can be a simple EventBus or event the more complex Vuex)
And finally, if you really like/have to pass the method as a prop, You can put it in an object, and pass that object as prop.