Vue render function pass props

How to Use Props in Vue: The Ultimate Guide (with Examples)

Vue recommends using templates to build your HTML in the vast majority of cases. There are situations however, where you really need the full programmatic power of JavaScript. Say you want to generate anchored headings:.

When you get started with a component that only generates a heading based on the level prop, you quickly arrive at this:.

A Better Way To Create Templates In Render Functions Explained

Much simpler! Sort of. The code is shorter, but also requires greater familiarity with Vue instance properties. In this case, you have to know that when you pass children without a v-slot directive into a component, like the Hello world!

Take this HTML for example:. Every element is a node. Every piece of text is a node. Even comments are nodes! A node is just a piece of the page. And as in a family tree, each node can have children i. Updating all these nodes efficiently can be difficult, but thankfully, you never have to do it manually. And in both cases, Vue automatically keeps the page updated, even when blogTitle changes. Taking a closer look at this line:. What is createElement actually returning?

It could perhaps more accurately be named createNodeDescriptionas it contains information describing to Vue what kind of node it should render on the page, including descriptions of any child nodes. Here are the arguments that createElement accepts:.

One thing to note: similar to how v-bind:class and v-bind:style have special treatment in templates, they have their own top-level fields in VNode data objects. All VNodes in the component tree must be unique.

That means the following render function is invalid:. For example, the following render function is a perfectly valid way of rendering 20 identical paragraphs:.

Wherever something can be easily accomplished in plain JavaScript, Vue render functions do not provide a proprietary alternative. For example, in a template using v-if and v-for :. There is no direct v-model counterpart in render functions - you will have to implement the logic yourself:. This is the cost of going lower-level, but it also gives you much more control over the interaction details compared to v-model. For the.

vue render function pass props

For all other event and key modifiers, no proprietary prefix is necessary, because you can use event methods in the handler:. You can access static slot contents as Arrays of VNodes from this. And access scoped slots as functions that return VNodes from this. To pass scoped slots to a child component using render functions, use the scopedSlots field in VNode data:. Starting with version 3. With prior versions of the plugin, your app would throw an error if h was not available in the scope.

The anchored heading component we created earlier is relatively simple. A functional component looks like this:. Note: in versions before 2. Everything the component needs is passed through contextwhich is an object containing:.

VueJS - Render Function

After adding functional: trueupdating the render function of our anchored heading component would require adding the context argument, updating this.GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together.

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Already on GitHub? Sign in to your account. I am trying to integrate Vue with Meteor Blaze and am working on rendering of Vue components from Blaze templates.

I would like to programmatically create an Vue instance new Vue But the important part is to also be able to update all of them afterwards. So if any of the props or args change, allowing to call a function to update them would be great.

I propose that propData could be a function. So that I could provide a reactive function which would be used to populate both props and args so any keys returned from the function which are not props would become args. Shouldn't be possible to autorun over the blaze data and then just affect it to the vue instance which will update it? But I do not see an easy way to determine which one should be props and which attrs and updating both of them as needed.

You can wrap your component inside a Vue instance: example. Yes, but this assigns all to propswhat if some of those are not defined on the target component as props? Do they get mapped to attrs automatically? Oh, just to support non-prop attributes which could be still bound to reactive value. So that user can set attributes without developer of the component knowing about those. See description and rationale here. I would like to support it in Blaze as well, if possible.

But it is not a big deal. But if Vue would have such a function, which would allow programmatically to set and update props and attrs like you can from template language, that would be very easy to do. It's generally to use non-vue libraries, but you will most likely write at least one Vue component to wrap it that should expose its features through props and events the point is using Vue components in Blaze anyway.

I do not think it is needed. You could directly use Vue components. At least this is what I am aiming for in this package. I don't get the fr You can already programmatically create Vue instances with new Vue.

Sharing an object as the state data will allow you to reuse the same data in multiple instances if needed. To trigger functions when things change, use watchers. What is missing? This is trickier than it seems. You can modify the props you pass down. I feel like you haven't dug enough your problem but at the same time, to me, it looks like you understand more than the average user.

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Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Credits to: nickmessing - see his answer. How are we doing? Please help us improve Stack Overflow. Take our short survey. Learn more. Vue, how to pass function in props in JSX render? Ask Question. Asked 1 year, 10 months ago. Active 1 year, 10 months ago.

Viewed times. My components looks like: App. Everettss Everettss Admittedly it's been a while since I've worked with Vue. Ben I've tried it - the same results: this. To be clear: this. I created one demo below, it works fine. Active Oldest Votes. Don't start your prop name with on.Check it out! I was once in your position, not entirely sure of what I was doing and feeling like I was drowning.

But I've learned a lot over the years, and now I want to pass that on to you. By the time you're finished reading this guide, you'll know everything you need to know about props in order to be a super productive Vue developer. Props are how we pass variables and other information around between different components.

This is similar to how in Javascript we can pass variables into functions as arguments:. Here we pass the variable myMessage into the function as the argument message. Inside the function we can access that value as message. Props work in a very similar way to this. We pass props to another component, and that component can then use that value. Vue uses one way data flow, meaning that data can only flow from a parent into a child component.

vue render function pass props

You cannot pass data from a child to a parent. And because that parent component "owns" that value it passed down, the child can't modify it. If only one component is allowed to change it, then it's easier to track down bugs since we know exactly where to look. If the reasoning here isn't super clear that's okay.

You'll understand how this works as you use Vue more and more. If you want to pass a value from your component into a child component, it's exactly like adding an HTML attribute:. The Camera component will then use the name and img props to render itself to the page. It might render something like this:. Here we render the name prop into the h2 tag, and use the img prop to set the src attribute on the img tag.

To do that we need to use a slightly different syntax, since instead of passing a string we want to use a Javascript expression:.

A Javascript expression is any snippet of Javascript. It could be a variable name like we have here, or something more complicated. For example, we could use a logical OR to use a default if we don't have an image for the camera:.

More commonly, we use the shorthand for v-bind which is just : and reduces clutter in the code:. Because you can put in any arbitrary piece of Javascript, you can do a lot of nifty little things, such as dynamically adding a class nameor implementing a hover. Before this code will actually work, we need to get the Camera component to actually listen to the props.Read that first if you are new to components.

HTML attribute names are case-insensitive, so browsers will interpret any uppercase characters as lowercase. In the two examples above, we happen to pass string values, but any type of value can actually be passed to a prop.

If you want to pass all the properties of an object as props, you can use v-bind without an argument v-bind instead of v-bind:prop-name.

For example, given a post object:. All props form a one-way-down binding between the child property and the parent one: when the parent property updates, it will flow down to the child, but not the other way around. In addition, every time the parent component is updated, all props in the child component will be refreshed with the latest value. This means you should not attempt to mutate a prop inside a child component.

If you do, Vue will warn you in the console.

vue render function pass props

The prop is used to pass in an initial value; the child component wants to use it as a local data property afterwards. The prop is passed in as a raw value that needs to be transformed. Note that objects and arrays in JavaScript are passed by reference, so if the prop is an array or object, mutating the object or array itself inside the child component will affect parent state. To specify prop validations, you can provide an object with validation requirements to the value of propsinstead of an array of strings.

For example:. Note that props are validated before a component instance is created, so instance properties e. In addition, type can also be a custom constructor function and the assertion will be made with an instanceof check.

For example, given the following constructor function exists:. A non-prop attribute is an attribute that is passed to a component, but does not have a corresponding prop defined. We can add this attribute to our component instance:. For most attributes, the value provided to the component will replace the value set by the component. Fortunately, the class and style attributes are a little smarter, so both values are merged, making the final value: form-control date-picker-theme-dark.

Note that inheritAttrs: false option does not affect style and class bindings.We have seen components and the usage of it. For example, we have a content that needs to be reused across the project.

We can convert the same as a component and use it. Consider the above example of a simple component that prints Hello World as shown in the following screenshot. However, now we need some changes to the component. How can we change it? In case, we type something inside the component, will it be take into consideration?

Component does provide something called as slots. As seen in the above code, in the template we have added slot, hence now it takes the value to send inside the component as shown in the following screenshot.

Now, let us consider we want to change the color and size. For example, currently we are using h1 tag and we want to change the HTML tag to p tag or div tag for the same component. How can we have the flexibility to carry out so many changes? We can do so with the help of the render function. Render function helps make the component dynamic and use the way it is required by keeping it common and helping pass arguments using the same component.

In the above code, we have changed the component and added the render function with props property using the following piece of code.

We have defined a property called elementtype, which takes attributes field of type string. Another required field, which mentions that the field is mandatory. In the render function, we have used the elementtype property as seen in the following piece of code.

Components Basics

Render function takes createElement as the argument and returns the same. We have also split the elementtype on comma, using the values in the attrs field.

CreateElement is taking the first param as the elementtag to be created. It is passed to the component using the following piece of code. The component needs to take the props field as shown above. It starts with : and the name of the props. Here, we are passing the element tag, color, fontsize, and the id of the element. In render function, in createElement, we are splitting on comma, so the first element is the elementtag, which is given to the createElemet as shown in the following piece of code.

The next parameter is the attributes for the element tag. They are defined in the attr field in the following piece of code. We have defined two attributes for the element tag - id and style.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here.

vue render function pass props

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I am quite new to VueJS. In react you can easily use rest params for passing props to children. Is there a similar pattern in Vue? What I don't like is that the props are named-spaced with the key configor any other arbitrary key. The text-input component not shown is a glorified input field that can take a number of attributes. I could flatten the props when the component is created, but is that generally a good idea? Learn more.

VueJS pass all props to child component Ask Question. Asked 2 years, 10 months ago. Active 1 year ago. Viewed 16k times. I don't like this config-dot property structure. I am surprised this question hasn't been asked before. Simon Simon 1, 3 3 gold badges 23 23 silver badges 42 42 bronze badges. You can pass an object as a prop, containing all needed key-value pairs. That's what I am I have illustrated here.

The :config key is the prop key on the child. Which is not what I want.

How to Use Props in Vue: The Ultimate Guide (with Examples)

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