Vue3 prints everthing as an a "Proxy" object.
I know the value is inside [[Target]], but I don't want to keep expading Proxy->[[Target]] every single time.
Just wanted to let clear, this does't change the output at all. it is just a 'cleaner' way to see stuff.
An example:
const b = 'value'
console.log(value)
Output -> { Proxy: { [[Handler]]: ..., [[Target]]: 'value', [[IsRevoked]]: false }
okay, this works.
console.log(JSON.parse(JSON.stringify(b))).
for more info.
Accessing a Proxy object in Vue3
Related
I'm attempting to set data fields provided by an array based on the Vue Router query. For example, when someone lands on my website using example.com/?location=texas, I want to set the location data by an array.
An example the array:
locations {
{
slug: "texas",
tagline: "Welcome to Texas",
}, {
slug: "california",
tagline: "Welcome to California",
}
}
I know this should be done using a computed property, however I am unable to get anything functioning. I've tried simple tests like if (this.slug.location === "texas"), and I cannot get the location data to populate. I would also like to provide default data in case there are no route matches.
Any help is extremely appreciated!
Edit:
I can accomplish this in a very manual way. Right now, I'm setting the query in data by the following:
slug: this.$route.query.location
I can display specific text by doing something like:
h3(v-if="slug === 'texas'") This will show for texas
h3(v-else-if="slug === 'california'") This will show for California
h3(v-else) This is default
The issue with this approach is there are various elements I need to customize depending on the slug. Is there any way I can create an array, and move whichever array matches a key in an array to the data??
You should be able to access a query param using the following (link to Vue Router documentation):
this.$route.query.location
So based on what you listed I would do something like...
export default {
computed: {
displayBasedOnLocationQueryParam() {
switch(this.$route.query.location) {
case 'texas':
return 'Welcome to Texas'
default:
return 'hello there, generic person'
}
}
}
}
Note that I'm not using your array explicitly there. The switch statement can be the sole source of that logic, if need be.
Hey guys I have the following function its working ok but I think it could be better.
methods: {
onFileChange(e, filedName) {
console.log(e.target.files);
console.log(filedName);
const file = e.target.files[0];
const fileToCheck=document.getElementById(filedName);
console.log(fileToCheck);
if(filedName=='thumbnail1'){
if(fileToCheck.value!=''){
this.thumbnail1 = fileToCheck;
this.thumbnail1Url= URL.createObjectURL(file);
} else {
this.thumbnail1=null;
this.thumbnail1Url=null;
}
}
if(filedName=='thumbnail2'){
if(fileToCheck.value!=''){
console.log(fileToCheck);
this.thumbnail2=fileToCheck;
this.thumbnail2Url = URL.createObjectURL(file);
} else {this.thumbnail2=fileToCheck; this.thumbnail2Url=null;}
}
},
Instead of checking the value for
if(fieldName == "something"){
this.something = URL.createObjectURL(file)
}
I would simply pass in a string of the fieldName and bind to it dynamically by just typing this.fieldName (filedName could equal thumbnail1 or thumbnail2 or chicken for all I care I just want to be able to pass in the name of the data atrribute and bind to it that way) but when ever I do this it doesn't work. Any help here would be great.
It's not completely clear to me what you want to accomplish, but I think you're asking about creating a dynamic data property for a view component. If that's the case, there are a couple of things to consider.
First, the example you cite, this.fieldName is not correct JavaScript syntax if fieldName is a string that contains a property name. The correct version is this[fieldName].
Note, though, that you can't simply define a new data property for a Vue component by setting it to a value. That's a limitation of JavaScript that's described in the Vue documentation. If data[fieldName] is an existing property that's defined in the component's data object, then you'll be okay. Even if you don't know the value of the property, you can initialize it, for example, with a value of null and then update the value in your method. Otherwise, you'll need to add the property to an existing non-root-level property as the documentation explains.
I understand with Vue JS 2, you have to declare reactive properties upfront.
However, just wondering how would you do a rest call if the child objects appear depending on a few other conditions. For example:
"abc": {
"tests": [
{
"a1": "xxxx",
"result": null,
"selected": false,
"comment": null
} ...
]
}
Now in this example, what happens if the tests are empty ((null)) in some circumstances?
eg: if you bind it using the v-model xx.xx.abc.tests[1].selected - This wont work as tests[1] is null.
So I tried using Vue.set in mounted function to assign a default value but that did not work. It will be hard to define all these in a static data as then I have to know all the tests before the rest call.
Looking at the Vue warning when accessing nested object the issue is if I do the check for inside
the checkbox (Checkbox is rendered from Spring MVC tag).
<form:checkbox id="xx" path="..Spring MVC Path.." v-if="(xx.xx.abc.tests!=null && xx.xxx.abc.tests[3].selected)" **v-model**="xx.xxx.abc.tests[3].selected"/>
The checkbox does not appear at all. I want it to appear regardless of empty value as it gives users to add the option. Also, the other option of statically declaring it does not work as I don't know want to hard code and define array.
for example that means in case another element is added it is hardcoded into script:
[
{
"testName": String,
"result": String,
"selected": false,
"comment": String
},
{
"testName": String,
"result": String,
"selected": false,
"comment": String
}
]
Basically I need to bind using v-model even if it is null in this case. Tried Vue.set but for some reason did not appear to work.
I guess I am missing something here,any help would be appreciated.
Assume that you have a list of checkbox to render whether the child element is null on not. but you do know the array length, right?
If you do, consider use v-for to render checkboxes (then you’re able to track array item by index) and listening on its change event then assign specific value to specific object when events fire
thanks for the replies. As this was due to rest call not returning all required attributes that was defined in Vue model(As mentioned in question).So I checked that in final section of rest call and if they are empty, created them.
axios
.get(***URL***)
.then(
response => {
this.info = response.data;
this.status.loaded = true;
}
)
.finally(
() => {
*** check and fill missing attributes with default values ***
**Example: this.$set(this.someObject, 'b', 2)
}
)
Reference:
https://v2.vuejs.org/v2/guide/reactivity.html
I have a 2D array of objects with key/value pairs as a state variable, and I'm trying to use the recommended way of setting/changing state variables, which is to use this.setState({x:y}) instead of directly setting it using this.state.x = y and then forceUpdate(). However, when I try to do that, it gives me an "unexpected token" error.
I basically want to flip a variable from one state to the other, so I'm usng a ternary operator. This code works
toggleBookmark(category, index) {
this.state.menuItems[category][index].bmIcon = (this.state.menuItems[category][index].bmIcon === "bookmark-o") ? "bookmark" : "bookmark-o";
}
This code, which I'd expect to do the same thing, gives an error
toggleBookmark(category, index) {
this.setState({menuItems[category][index].bmIcon: (this.state.menuItems[category][index].bmIcon === "bookmark-o") ? "bookmark" : "bookmark-o"});
}
I thought it might be the ternary operator, so I put the value into a variable and tried setting the state variable with that, but it still gives the same error.
toggleBookmark(category, index) {
var iconText = (this.state.menuItems[category][index].bmIcon === "bookmark-o") ? "bookmark" : "bookmark-o";
this.setState({menuItems[category][index].bmIcon: iconText});
}
Am I doing something wrong? Is what I want to do possible with setState()?
In Javascript, you cannot use an expression as a key for an object when creating that object inline.
The problem here is that you have done {menuItems[category][index].bmIcon: iconText} which will throw a syntax error.
If you want a quick way to solve this, you may create the object first, then assign the value to that key like this:
var state = {};
state[menuItems[category][index].bmIcon] = iconText;
this.setState(state);
It's worth noting however that ES6 Provides a sugar for doing this, and there is another answer here that might provide more insight
How do I create a dynamic key to be added to a JavaScript object variable
Update:
I now see what you meant, I had previously assumed that menuItems already defined, but what you want to do is change the value of a key inside a nested object that is in this.state
This is something that React is not really built to do, you should keep your state relatively simple, and make separate React components for each menu item, then have them manage their own state. I would strongly recommend this approach because it will keep your code clean and robust. Don't be afraid to make more components!
However if you do want to keep all this nested state in one component (not advised), then you should first make a copy of the object you want to setState on.
var newMenuItems = _.clone(this.state.menuItems);
var iconText = (this.state.menuItems[category][index].bmIcon === "bookmark-o") ? "bookmark" : "bookmark-o";
newMenuItems[category][index].bmIcon = iconText;
this.setState({ menuItems: newMenuItems });
OR
var iconText = (this.state.menuItems[category][index].bmIcon === "bookmark-o") ? "bookmark" : "bookmark-o";
this.state.menuItems[category][index].bmIcon = iconText;
this.forceUpdate();
(First method preferred, but it requires you have something like underscore or lodash installed )
I have the data chat:
chat: {
id: 'ss3k5e6j1-6shhd6-sdasd3d3-23d5-gh67',
agentName: 'egaliciar',
agentAvatar: 'http://i.imgur.com/DY6gND0.png',
messages: [
{
id: 1,
lines: [
'Me pueden ayudar?',
'Tengo problemas con mis boletos',
'Hola buen dia...',
],
time: '17:20',
},
{
id: 2,
lines: ['¿Me podria regalar su nombres', 'Con gusto...'],
time: '17:22',
date: '23/ene/2012',
},
],
},
};
and when i do
const oldLines =Object.assign({}, this.state.chat);
oldLines.messages[0].lines.push('newValue');
My state Changed..... without this.setState({});
I Made a Clone;
var clone = JSON.parse(JSON.stringify(this.state.chat));
clone.messages[0].lines.push('new Value');
and the State maintain their state;
thus, the complete solution is for me:
var clone = JSON.parse(JSON.stringify(this.state.chat));
clone.messages[0].lines.push(questionAreaMessage); //the state maintains
this.setState({chat:clone}); //here the State change!!!!
Hopefully I'm describing this correctly. I'm making a windows store app and I have the following setup
WinJS.Namespace.define("Model",
{
WorkOrders: new WinJS.Binding.List(),
selectedWorkOrder: {}
});
WinJS.Namespace.define("ViewModel",
{
WorkOrders: Model.WorkOrders,
selectedWorkOrder: Model.selectedWorkOrder
})
When the page is loaded an ajax request populates a list of WorkOrders, after they're populated a user can select one, at which point Model.selectedWorkOrder is set to one of the objects in Model.WorkOrder.
I want ViewModel.selectedWorkOrder to reflect whatever Model.selectedWorkOrder is, but it seems to bind only to the originally empty object, how can I make it bind to that property (even if the object changes, like a pointer).
I'm doing something like this to set the selectedWorkOrder
Model.selectedWorkOrder = results[i];
Thanks!
Not sure if I understand your question correctly.
What you're looking for is some kind of event to get in ViewModel.selectedWorkOrder whatever Model.selectedWorkOrder has, right?
If that's the case you could try RxJS-WinJS (which I'm honestly not too familiar with) or you could just make ViewModel.selectedWorkOrder a method that gets and returns whatever Model.selectedWorkOrder has at any given time.
Something like this:
WinJS.Namespace.define("Model",
{
WorkOrders: new WinJS.Binding.List(),
selectedWorkOrder: {}
});
var _getWorkItem = function(){
return Model.selectedWorkItem;
}
WinJS.Namespace.define("ViewModel",
{
WorkOrders: Model.WorkOrders,
selectedWorkOrder: _getWorkItem
})