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Already on GitHub? Sign in to your account. When you select new value in select element, text below will be updated to selected value. But in FF it is equal to last selected value. This is just a difference in how Firefox processes and stores element attributes compared to Webkit and Blink I'm not sure what IE does.
Run this example in Firefox and Chrome —the order is reversed. Vue doesn't give the model directive special priority over other directives.Vue js 2 Tutorial - 5 - Binding Text
I know this is very old thread but I am not sure if this browser consistence problem has been solved.
I am trying to capture the change of a. In Chrome, with key press, the value of model changes but in Firefox, only mouse can make model changes. Nothing comes out of onChange. Any suggestions?
The way I first tried it was. But that called the addThing method before the thing variable was set. Here's the watch that made it work:.
I just want to ask on how can I add or upload the same file? Oliboy50 nextTick is called when the DOM changed, if i am correct. Add a notify method to the methods object where myVal is the data you are binding to:.
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Sign up. New issue. Jump to bottom. Copy link Quote reply. Hi, I noticed that in FF onChange event is triggered before v-model variable is updated. In all other browsers variable is updated first. This comment has been minimized. Sign in to view. Improve v-model behavior Use a watcher to update a selected option instead of the change event …. I found a way to solve this problem.All Vue.
You can also perform one-time interpolations that do not update on data change by using the v-once directivebut keep in mind this will also affect any other bindings on the same node:. The double mustaches interprets the data as plain text, not HTML. In order to output real HTML, you will need to use the v-html directive :.
The contents of the span will be replaced with the value of the rawHtml property, interpreted as plain HTML - data bindings are ignored.
Note that you cannot use v-html to compose template partials, because Vue is not a string-based templating engine. Instead, components are preferred as the fundamental unit for UI reuse and composition. Only use HTML interpolation on trusted content and never on user-provided content. Mustaches cannot be used inside HTML attributes. Instead, use a v-bind directive :. In the case of boolean attributes, where their mere existence implies truev-bind works a little differently.
Because v-if is a directive, it has to be attached to a single element. But what if we want to toggle more than one element? A v-else element must immediately follow a v-if or a v-else-if element - otherwise it will not be recognized. It can also be chained multiple times:.
Similar to v-elsea v-else-if element must immediately follow a v-if or a v-else-if element. Vue tries to render elements as efficiently as possible, often re-using them instead of rendering from scratch. Beyond helping make Vue very fast, this can have some useful advantages. For example, if you allow users to toggle between multiple login types:.
Then switching the loginType in the code above will not erase what the user has already entered. Another option for conditionally displaying an element is the v-show directive.
The usage is largely the same:. The difference is that an element with v-show will always be rendered and remain in the DOM; v-show only toggles the display CSS property of the element. In comparison, v-show is much simpler - the element is always rendered regardless of initial condition, with CSS-based toggling.
Generally speaking, v-if has higher toggle costs while v-show has higher initial render costs. So prefer v-show if you need to toggle something very often, and prefer v-if if the condition is unlikely to change at runtime. Using v-if and v-for together is not recommended. See the style guide for further information.
When used together with v-ifv-for has a higher priority than v-if. See the list rendering guide for details. Stay at home and level up. Special Sponsor. Platinum Sponsors. Learn how conditional rendering works with a free lesson on Vue School.
Username Email.In-template expressions are very convenient, but they are meant for simple operations. Putting too much logic in your templates can make them bloated and hard to maintain. For example:. At this point, the template is no longer simple and declarative.
You have to look at it for a second before realizing that it displays message in reverse. The problem is made worse when you want to include the reversed message in your template more than once.
Here we have declared a computed property reversedMessage. The function we provided will be used as the getter function for the property vm. You can open the console and play with the example vm yourself. The value of vm. You can data-bind to computed properties in templates just like a normal property. Vue is aware that vm. Instead of a computed property, we can define the same function as a method. For the end result, the two approaches are indeed exactly the same.
However, the difference is that computed properties are cached based on their reactive dependencies. A computed property will only re-evaluate when some of its reactive dependencies have changed. This means as long as message has not changed, multiple access to the reversedMessage computed property will immediately return the previously computed result without having to run the function again.
Dynamic Styles With Vue.js
This also means the following computed property will never update, because Date. In comparison, a method invocation will always run the function whenever a re-render happens. Why do we need caching? Imagine we have an expensive computed property Awhich requires looping through a huge Array and doing a lot of computations. Then we may have other computed properties that in turn depend on A. In cases where you do not want caching, use a method instead.
Vue does provide a more generic way to observe and react to data changes on a Vue instance: watch properties. When you have some data that needs to change based on some other data, it is tempting to overuse watch - especially if you are coming from an AngularJS background.
However, it is often a better idea to use a computed property rather than an imperative watch callback. Consider this example:. Computed properties are by default getter-only, but you can also provide a setter when you need it:. Now when you run vm.In the next couple of lectures, we are going to see how we can apply styling to our elements and make things just a bit more interesting. We are first going to start out by adding inline styles to elements with the style HTML attribute.
Since we are going to bind to an HTML attribute, we are going to use the v-bind directive again. I have added a simple div in advance which is pixels in width and height, and the first thing I want to do, is to set its background color to blue.
For the value, I can simply write red enclosed in single quotes as well. Of course this is not all that useful, because we defined the color directly within our template. Now I just need to write the name of this property as the expression for the background-color style, and the result will be the same. Now of course this is not too useful either, because we have hard coded the color within our Vue instance.
But what this enables us to do, is to change the color dynamically. And, you guessed it, when doing this, Vue. To show you this, I will add a button with a click event listener which changes the color. And now the event listener. This listener will simply use an if statement to switch the color from blue to red and vice verca.
If I click the button now, we will see that the background color of the div changes. As you can probably imagine, it can quickly become difficult to read if we add more properties to the object within the template.
To solve this, we can simply move the object to a data property and refer to this property within the template. I will call the property styles.No design skills required — everything you need to create amazing applications is at your fingertips. Building applications with Vue has never been easier. Supercharge your development process with all of the tools you need to succeed. When you run into a roadblock, you need assistance right away. Vuetify offers support in our massive community on Discord.
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The dark mode beta is finally here. Change your preferences any time. Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. I'm playing with vue. For now, everything is within one component. I want to change the text of a button after it is clicked to hide an element from "hide" to "show" - I'm going about this by setting a text data object and then changing it in a function.
Unexpectedly, the button is blank on both hide and show states. Being new to vue, this seems like a strange way to go about doing it. Is changing data in this context bad practice?
Computed Properties and Watchers
I don't understand how to fix this, as I have no errors in my console. I change your button by a plain object instead of an array and small adaptation in method toggleSeen. Learn more. Asked 2 years, 6 months ago. Active 11 months ago. Viewed 25k times. Why is your button data property an array? Active Oldest Votes. Here you have your code in a snipplet.
Camille Camille 1, 8 8 silver badges 22 22 bronze badges. This is good and solves the problem! However I'm having trouble understanding the line app. So you're just setting an opposite condition on every event? I read that as app.
If condition result is true, then false is return and if condition result is false, true is return. That is same to do if app. Sign up or log in Sign up using Google. Sign up using Facebook.
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