How should one refer to the value set up within an object passed to v-bind to display it?
Example:
<p v-bind="{id: 'myId'}">{{ /*what to state here to have 'myId' displayed?*/ }}</p>
The <p> is not a child component, everything here is all in the same scope. You cannot refer to its attributes from its contents. As in Bert's example, you simply have to put what you want in both places.
If you want to use a variable for the id and for the contents, you can do that, but you have to explicitly put it in both places:
<p :id="myIdVariable">{{myIdVariable}}</p>
Related
I am writing a custom TagHelper that should change its behavior based on what child elements its owner tag has. This will be used for substituting custom html elements in a localized string.
Here's a simple example of what I'm trying to do:
<h2 locale-key="Hello, %1!">
<span class="bold" locale-parameter="1">#userName</span>
</h2>
In the example above, the TagHelper for LocaleKey will change the content of the <h2> tag to a localized string. If this is a simple string with no parameters, then I can just simply use output.Content.SetHtmlContent() in the TagHelper to set the h2's content to the string. However in this case, the localized string has a parameter (%1), and I want the corresponding child element (<span parameter="1">) to be substituted in the final output. So the final rendered html would look like this:
<h2>Hello, <span class="bold">Lázár Zsolt</span>!<h2/>
To achieve this, I should be able to see all the child elements in the DOM from the LocaleKey TagHelper, so I can generate the correct HTML code. In the TagHelper's ProcessAsync method I can access the TagHelperContext and the TagHelperOutput, but I couldn't find any information about child elements in either of these objects while debugging. Is this possible somehow?
Another approach is to leave the string as is, with the %1 parameter key, and then use the child ParameterTagHelper to substitute itself into the parameterized string. To do this, I'd have to see the siblings of the current tag from the TagHelper.
Recursion would also be fun (e.g. the <span> is also localized and has its own parameters), but for the scope of this question, I'd be happy if I could get this to work without recursion.
I posted too soon again... There is a GetChildContentAsync() method in TagHelperOutput that will... get the child content asynchronously.
the question I have might be hard to understand, so please help me re-organize the question if you can see the better way to put it in.
So, I am building a registration platform.
(1) First, I receive an array of objects of cases the user can sign time to.
(2) Each object consists of 2 properties, "name", "description".
(3) I store the array in the data, end use it in the element provided by a picker called "vue-multiselect", which basically accepts the array and loops over the objects and displays them.
(4) As you can see, it displays both properties and values, which I am trying to avoid. My question is, is it possible to pass only the "name" value into the picker, and display the description value when hovering the first value?
You can find this use case documentation here: https://vue-multiselect.js.org/#sub-custom-option-template
<multiselect v-model="value"
deselect-label=""
select-label=""
placeholder=""
selected-label=""
:show-pointer="true"
:options="projectCases">
<template slot="option" slot-scope="{ option }">
<strong :title="option.description">{{ option.name }}</strong>
</template>
</multiselect>
ps: I use title attribute to implement display-on-hover functionality. you can use any other tooltip library as well.
I'm learning Vue with an online course and the instructor gave me an exercise to make an input text with a default value. I completed it using v-model but, the instructor chose v-bind:value and I don't understand why.
Can someone give me a simple explanation about the difference between these two and when it's better use each one?
From here -
Remember:
<input v-model="something">
is essentially the same as:
<input
v-bind:value="something"
v-on:input="something = $event.target.value"
>
or (shorthand syntax):
<input
:value="something"
#input="something = $event.target.value"
>
So v-model is a two-way binding for form inputs. It combines v-bind, which brings a js value into the markup and v-on:input to update the js value. The js value must be present in your data, or in an inject.
Use v-model when you can. Use v-bind/v-on when you must :-) I hope your answer was accepted.
v-model works with all the basic HTML input types (text, textarea, number, radio, checkbox, select). You can use v-model with input type=date if your model stores dates as ISO strings (yyyy-mm-dd). If you want to use date objects in your model (a good idea as soon as you're going to manipulate or format them), do this.
v-model has some extra smarts that it's good to be aware of. If you're using an IME ( lots of mobile keyboards, or Chinese/Japanese/Korean ), v-model will not update until a word is complete (a space is entered or the user leaves the field). v-input will fire much more frequently.
v-model also has modifiers .lazy, .trim, .number, covered in the doc.
In simple words
v-model is for two way bindings means: if you change input value, the bound data will be changed and vice versa.
but v-bind:value is called one way binding that means: you can change input value by changing bound data but you can't change bound data by changing input value through the element.
check out this simple example: https://jsfiddle.net/gs0kphvc/
v-model
it is two way data binding, it is used to bind html input element when you change input value then bounded data will be change.
v-model is used only for HTML input elements
ex: <input type="text" v-model="name" >
v-bind
it is one way data binding,means you can only bind data to input element but can't change bounded data changing input element.
v-bind is used to bind html attribute
ex:
<input type="text" v-bind:class="abc" v-bind:value="">
<a v-bind:href="home/abc" > click me </a>
v-model is for two way bindings means: if you change input value, the bound data will be changed and vice versa. But v-bind:value is called one way binding that means: you can change input value by changing bound data but you can't change bound data by changing input value through the element.
v-model is intended to be used with form elements. It allows you to tie the form element (e.g. a text input) with the data object in your Vue instance.
Example: https://jsfiddle.net/jamesbrndwgn/j2yb9zt1/1/
v-bind is intended to be used with components to create custom props. This allows you to pass data to a component. As the prop is reactive, if the data that’s passed to the component changes then the component will reflect this change
Example: https://jsfiddle.net/jamesbrndwgn/ws5kad1c/3/
Hope this helps you with basic understanding.
There are cases where you don't want to use v-model. If you have two inputs, and each depend on each other, you might have circular referential issues. Common use cases is if you're building an accounting calculator.
In these cases, it's not a good idea to use either watchers or computed properties.
Instead, take your v-model and split it as above answer indicates
<input
:value="something"
#input="something = $event.target.value"
>
In practice, if you are decoupling your logic this way, you'll probably be calling a method.
This is what it would look like in a real world scenario:
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<input :value="extendedCost" #input="_onInputExtendedCost" />
<p> {{ extendedCost }}
</div>
<script>
var app = new Vue({
el: "#app",
data: function(){
return {
extendedCost: 0,
}
},
methods: {
_onInputExtendedCost: function($event) {
this.extendedCost = parseInt($event.target.value);
// Go update other inputs here
}
}
});
</script>
Is there any reason why a repeat.for binding would remove attributes from elements inside the repeater?
<div repeat.for="i of model.someArray.length">
<label>Some Array - Index ${i + 1}</label>
<input value.bind="model.someArray[i]" some-custom-attribute="someArray[${i}]"/>
</div>
and that some-custom-attribute is not being output within the repeat, but if I were to remove the string interpolation within there then it outputs fine.
== Edit ==
I have put it in a comment but just to make sure everyone is on the same page, ideally this is the output I expect:
<input value.bind="model.someArray[i]" some-custom-attribute="someArray[0]"/>
The some-custom-attribute is not an aurelia attribute, its pure HTML that a 3rd party JS library uses, so the goal here is to get the textual value of the index into the textual attribute value.
model.someArray.length is a number, not an array. You need to iterate over the array. If you do need the current index, the repeater provides the $index property for you to use.
Your code should look like this:
<div repeat.for="item of model.someArray">
<label>Some Array - Index ${$index + 1}</label>
<input value.bind="item" some-custom-attribute.bind="item"/>
</div>
To answer your original question, doing some-custom-attribute="model.someArray[${i}]" makes Aurelia think you are trying to pass a string value to the custom attribute. You can see that in the following gist: https://gist.run/?id=eed8ac8623ff4749aa5bb93c82a7b1fb I've created a custom element that just pushes whatever value it is given in to an element on the page. Note!!! Don't ever do what I'm doing here! I just did this this way so you wouldn't have to open the js console. To actually get a value passed in, you would need to use some-custom-attribute.bind="item" or (to do things how you are doing things, some-custom-attribute.bind="someArray[i]"
I am aware in Vue, every reactive data properties need to be declared in the Vue instance.
I have a situation where I need pull sets of data from the server, say tickets, and I need to have a model associated to each of these data when using v-for
Is there any way I can name the v-model using the ticket variable properties, ie the id. Is this possible?
v-model="{{ ticket.id }}"
If it is possible, how I declare the reactive data properties in vue instance dynamically?
Something like this:
<div id="example-1">
<div v-for="ticket in tickets">
<p> {{ticket.name }} </p>
<input type="number" v-model="{{ ticket.id }}" min="0" placeholder="0">
</div>
</div>
Answer of second question
You can use vm.$set for your case. This can add new reactive properties dynamically.
Set a property on an object. If the object is reactive, ensure the property is created as a reactive property and trigger view updates.
So once you receive response from server, you can apply vm.$set on the received object.
Answer of first question
Yes, you can name the v-model using the ticket variable properties using v-model, however syntax you are using is little wrong, it should be:
v-model="ticket.id"
Assuming you populate the tickets array in your Vue components' data object once received from the server, you can then iterate the array of tickets as you laid out in your example.
You can then tie the input model to the ticket object property directly:
<input type="number" v-model="ticket.id" min="0" placeholder="0">