Fortunately, Vue provides a 'context' parameter (often referred to as ctx) to the underlying render function. This 'context' argument is an object with the following properties: props: An object of the provided props; children: An array of the VNode children; slots: A function returning a slots object. The benefits of props as component slots in React. 04 February, 2019. Composing components with more granular and simpler ones already present in the codebase is a pretty standard situation inside both a web application and, as in my case, a design system repository.
Composing components with more granular and simpler ones already present in the codebase is a pretty standard situation inside both a web application and, as in my case, a design system repository.
Vue Select leverages scoped slots to allow for total customization of the presentation layer. Slots can be used to change the look and feel of the UI, or to simply swap out text. # footer 3.8.0+ Displayed at the bottom of the component, below.vsdropdown-toggle. Here is my opinion on it. When crafting components with Vue.js you can go multiple ways. You can go with the props based approach or you can choose the slot based solution. If you're using props. As you can see, this looks very similar to the render prop in our React component. Here, we are returning a default scoped slot, which passes along an object with whatever we want. Here, we give it the results and our search method. In our autocomplete component, we use the slot-scope attribute to get access to the data from the child component.
Imagine for example a button component that you can use anywhere, but also a modal Dry ace poker. component that consumes it as part of its basic interface.
You might already have seen lots of different approaches and techniques for composition in React, like render props or child functions. In this case, I'm going to show you props as component slots or children prop.
And if you have a better name for this please reach out.
# Things to solve
The best way to explain this pattern, and where it shines, is to present the issues and code smells it solved for me.
# Prop 'drilling'
Let's go back to the example I mentioned with a button component available for use and also consumed by a modal and think about its possible prop signature.
The button's content could be the children prop, a kind prop to indicate whether it is a primary or secondary action, an icon prop in case we want an SVG image prepend inside its content and an onClick prop for the click event.
How modal should handle the customization of its button? The immediate thing we do is to match all the props at the component level.
Of course there's nothing particularly wrong with the code above and you are going to be just fine with this, specially if these two components are unlikely to change with time.
But if they do then maintenance might become a little pain, even more if you use this pattern for button a lot across your codebase.
It can get even worse if for some reason you have one more component layer between Modal
and Button
.
# Duplicated type definitions
Whether you are using prop types or any language superset to define types, you will have duplicated and unnecessary definitions all over the place, matching exactly the button props definition.
If the signature of the component expands, it will translate into even more work and duplicated definitions, and for something that might be trivial.
# Props as component slots
The solution I've found is to pass component through props, this allows you to render a component in a certain section.
Whenever we use Modal
, we just pass an instance of Button
to action.
I haven't experience any inconvenience by doing this. The result is cleaner and more extensible code as we pass the props to Button
directly to the element.
Other stuff you can do is to force certain configuration of the component, for example let's force any button passed to be secondary.
No matter what the developer defines for kind
in the button it will be ignored and 'secondary'
will always be the prop value. This is super useful inside design systems when trying to force certain visual patterns.
# Type checking
One thing that I don't like much about this, and couldn't figure out a better way to do it, is prop type checking of the component is passed.
It's necessary to import the component and check the instance.
Before you say it, no, the following approach doesn't work.
Slots Vs Props Vue On Tv
No deposit bonus coupon codes silver oak casino 2018. I still think this is a small price to pay, giving all the unnecessary prop manipulation it's saved me, specially inside the design system repository on my current job where internal components are reused as much as possible.
# Wrap up
This technique, props as component slots or however you think this should be called, avoids unnecessary prop handling and repeated type checking.
I haven't detected performance regression around this, but if you do, think about the possibility of switching to another approach that still gives you these benefits while controlling better render cycles.
My recommendation is to hoist the element when possible.
If the action doesn't depend on a higher prop to define its configuration, then turning it into a static element piece will avoid reconciliation around it.
For further reading, I recommend the Composition vs. Inheritance section of the official React docs where this approach receives a short mention at the beginning.
This page assumes you've already read the Components Basics. Read that first if you are new to components.
Slot Content
Vue implements a content distribution API that's modeled after the current Web Components spec draft, using the element to serve as distribution outlets for content.
This allows you to compose components like this:
Then in the template for , you might have: Casino package kathmandu.
When the component renders, the element will be replaced by 'Your Profile'. Slots can contain any template code, including HTML:
Or even other components:
If did not contain a
element, any content passed to it would simply be discarded.
Named Slots
There are times when it's useful to have multiple slots. For example, in a hypothetical base-layout
component with the following template:
For these cases, the element has a special attribute,
name
, which can be used to define additional slots:
To provide content to named slots, we can use the slot
attribute on a element in the parent:
Or, the slot
attribute can also be used directly on a normal element:
There can still be one unnamed slot, which is the default slot that serves as a catch-all outlet for any unmatched content. In both examples above, the rendered HTML would be:
Default Slot Content
There are cases when it's useful to provide a slot with default content. For example, a component might want the content of the button to be 'Submit' by default, but also allow users to override with 'Save', 'Upload', or anything else.
To achieve this, specify the default content in between the tags.
If the slot is provided content by the parent, it will replace the default content.
Compilation Scope
Slots Vs Props Vue App
When you want to use data inside a slot, such as in:
That slot has access to the same instance properties (i.e. the same 'scope') as the rest of the template. The slot does not have access to ‘s scope. For example, trying to access
url
would not work. As a rule, remember that:
Everything in the parent template is compiled in parent scope; everything in the child template is compiled in the child scope.
Scoped Slots
New in 2.1.0+
Sometimes you'll want to provide a component with a reusable slot that can access data from the child component. For example, a simple component may contain the following in its template:
But in some parts of our app, we want the individual todo items to render something different than just the todo.text
. This is where scoped slots come in.
To make the feature possible, all we have to do is wrap the todo item content in a element, then pass the slot any data relevant to its context: in this case, the
todo
object:
No deposit bonus coupon codes silver oak casino 2018. I still think this is a small price to pay, giving all the unnecessary prop manipulation it's saved me, specially inside the design system repository on my current job where internal components are reused as much as possible.
# Wrap up
This technique, props as component slots or however you think this should be called, avoids unnecessary prop handling and repeated type checking.
I haven't detected performance regression around this, but if you do, think about the possibility of switching to another approach that still gives you these benefits while controlling better render cycles.
My recommendation is to hoist the element when possible.
If the action doesn't depend on a higher prop to define its configuration, then turning it into a static element piece will avoid reconciliation around it.
For further reading, I recommend the Composition vs. Inheritance section of the official React docs where this approach receives a short mention at the beginning.
This page assumes you've already read the Components Basics. Read that first if you are new to components.
Slot Content
Vue implements a content distribution API that's modeled after the current Web Components spec draft, using the element to serve as distribution outlets for content.
This allows you to compose components like this:
Then in the template for , you might have: Casino package kathmandu.
When the component renders, the element will be replaced by 'Your Profile'. Slots can contain any template code, including HTML:
Or even other components:
If did not contain a
element, any content passed to it would simply be discarded.
Named Slots
There are times when it's useful to have multiple slots. For example, in a hypothetical base-layout
component with the following template:
For these cases, the element has a special attribute,
name
, which can be used to define additional slots:
To provide content to named slots, we can use the slot
attribute on a element in the parent:
Or, the slot
attribute can also be used directly on a normal element:
There can still be one unnamed slot, which is the default slot that serves as a catch-all outlet for any unmatched content. In both examples above, the rendered HTML would be:
Default Slot Content
There are cases when it's useful to provide a slot with default content. For example, a component might want the content of the button to be 'Submit' by default, but also allow users to override with 'Save', 'Upload', or anything else.
To achieve this, specify the default content in between the tags.
If the slot is provided content by the parent, it will replace the default content.
Compilation Scope
Slots Vs Props Vue App
When you want to use data inside a slot, such as in:
That slot has access to the same instance properties (i.e. the same 'scope') as the rest of the template. The slot does not have access to ‘s scope. For example, trying to access
url
would not work. As a rule, remember that:
Everything in the parent template is compiled in parent scope; everything in the child template is compiled in the child scope.
Scoped Slots
New in 2.1.0+
Sometimes you'll want to provide a component with a reusable slot that can access data from the child component. For example, a simple component may contain the following in its template:
But in some parts of our app, we want the individual todo items to render something different than just the todo.text
. This is where scoped slots come in.
To make the feature possible, all we have to do is wrap the todo item content in a element, then pass the slot any data relevant to its context: in this case, the
todo
object:
Now when we use the component, we can optionally define an alternative
for todo items, but with access to data from the child via the
slot-scope
attribute:
In 2.5.0+, slot-scope
is no longer limited to the element, but can instead be used on any element or component in the slot.
Destructuring slot-scope
The value of slot-scope
can actually accept any valid JavaScript expression that can appear in the argument position of a function definition. This means in supported environments (single-file components or modern browsers) you can also use ES2015 destructuring in the expression, like so:
This is a great way to make scoped slots a little cleaner.