I try to test a code and got the Exception below:
The component(s) below failed to render. Possible reasons could be that: 1) you have added a component in code but forgot to reference it in the markup (thus the component will never be rendered), 2) if your components were added in a parent container then make sure the markup for the child container includes them in .
I don't know what to do now.
This error means that you have added a component in your Java code, e.g.:
add(new Label("someId", "Some text"));
but you forgot to add wicket:id="someId" to the corresponding HTML template.
So, Wicket says: I have a component in the Java component tree that I have no idea where and how to render.
Related
Currently when importing components from another file to be used inside the template part, if the name of the component is not correct, Vue just gives a warning about this. Is there any way to configure it so that it errors during compilation or building, so that it is easier to do refactoring or moving around components, since in Nuxt, we can enable auto-discovery component, just that we need to include the directory it is in as well as part of the component name. For example, if I have a component named PhoneNumber inside base folder inside components folder, I can use that component directly by using BasePhoneNumber.
I have tried disabling the auto-discovery component in Nuxt, and I got a lot of this unknown custom element as expected. But this only triggers the warning, which I can only see the warning when I'm browsing that page. So there's a big chance of making a mistake where I update the name of the component in one page, but another one in another page is missed
I have to code a web application and the most important element is the q-tree. I'm already able to load and show data (passing an array called list), but I want that all nodes are expanded.
The vue.js examples of the official documentation show that you're be able to do this with the 'default-expand-all' attribute but this isn't working for me.
It only shows me the root node with an arrow, where I have to expand the children nodes manually.
<q-tree
:nodes="list"
:selected.sync="selected"
#update:selected="onSelectionChangedNode"
node-key="NodeNr"
label-key="NodeTxt"
default-expand-all
></q-tree>
Taking a cue from the accepted answer, I realised that the dom has already been created with the tree component on first render.
In my use case, I want to update the Tree when data comes back from the server.
So, I had to force it to re-render with the expanded functionality using:
this.$nextTick(function () {
this.$refs.nodes.expandAll();
})
The nextTick function will update the dom in the next window of execution, by which time the nodes will get expanded by calling the expandAll function.
And NB: For those confused by the astericks on the ref attribute or how to add it to the component, here goes:
<q-tree :nodes="list"
:selected.sync="selected"
#update:selected="onSelectionChangedNode"
node-key="NodeNr"
label-key="NodeTxt"
ref="nodes"
>
Solved my problem as following:
I have added a ref attribute to the QTree DOM Element which makes it possible to access predefined methods of QTree API.
<q-tree
:nodes="list"
:selected.sync="selected"
#update:selected="onSelectionChangedNode"
node-key="NodeNr"
label-key="NodeTxt"
**ref="nodes"**
>
The function I have been using is expandAll().
updated() {
this.$refs.nodes.expandAll();
}
The most important thing for me was, I had to find out which lifecycle hook was the right one for me. The update() hook was the one I was looking for.
The reason:
Called after a data change causes the virtual DOM to be re-rendered and
patched.
The component’s DOM will have been updated when this hook is called, so you
can perform DOM-dependent operations here.
The default-expand-all is only applied on the first rendering of that Component.
So if your Component renders when the nodes aren't assigned they wont expand if assigned afterwards.
https://v1.quasar-framework.org/vue-components/tree
You have to work with scoped slots and an expanded attribute if you dont have the nodes on first rendering.
I am currently developing a web application that is used to display elements for events on a map provided by HERE Maps. I am using Vue.
I have some components, but the relevant component is the component HereMaps.vue which initializes the map using the HERE Maps Api.
The HERE Maps Api provides the possibility to place so called InfoBubbles on the map showing additional information. These InfoBubbles can be provided some HTML-code in order to customize their appearance.
Please refer to the documentation for additional information
Following the documentation the code looks something like this:
let bubble = new H.ui.InfoBubble(marker.getPosition(), {
content: "<div class='someClass'>Some Content</div>"
});
this.ui.addBubble(bubble)
This is happening after mount in the "mounted" method from Vue in the "HereMaps" component.
The Bubbles are added in a "closed" (hidden) form and dynamically "opened" to reveal their content when the corresponding marker icon on the map is clicked. Therefore the HTML-code is present on the DOM after the component is mounted and is not removed at a later stage.
Now instead of supplying custom code within each bubble added to the UI i want to just add a component like this:
let bubble = new H.ui.InfoBubble(marker.getPosition(), {
content: "<myDynamicComponent></myDynamicComponent>"
});
this.ui.addBubble(bubble)
It does not matter to me wether the component is initialized using props or if it is conditionally rendered depending on the state of a global variable. I just want to be able to use the "myDynamicComponent" in order to customize the appearance in a different file. Otherwise the design process gets very messy.
As far as i know this is not possible or at least i was not able to get it work. This is probably due to the fact that the "myDynamicComponent" is not used within the "template" of the "HereMaps" component und thus Vue does not know that it needs to render something here after the directive is added to the DOM in the "mounted" method.
This is what the InfoBubble looks using normal HTML as an argument:
This is what the InfoBubble looks using the component as an argument:
It appears to just be empty. No content of the "myDynamicComponent" is shown.
Does anyone have any idea how i could solve this problem.
Thank You.
Answer is a bit complicated and I bet you wouldn't like it:)
content param can accept String or Node value. So you can make new Vue with rendered your component and pass root element as content param.
BTW, Vue does not work as you think, <myDynamicComponent></myDynamicComponent> bindings, etc exists in HTML only in compile time. After that all custom elements(components) are compiled to render functions. So you can't use your components in that way.
Give us fiddle with your problem, so we can provide working example:)
I know in vue, I can use this.$parent to get the upper component in the vdom tree. But I'm expecting something different: to get the component that rendered the current component.
For instance, I have a component (named comp-container) with template:
<template>
<comp-a>
<comp-b></comp-b>
</comp-a>
</template>
And in comp-b the $parent would be an instance of comp-a not comp-container which I'm expecting.
My current aproach is traversing up with the $parent attribute until I find comp-b exists in $options.components. This method is working for now but seems quite ugly and breaks if comp-b is a globaly registered component. Is there an official way to do this?
Passing the parent template component via props as <comp-b :container="this"></comp-b> may do the job, but it's too verbose to be liked.
I'm not sure about the exact use case, but basically if there are slots involved (which I almost assume, because otherwise $parent will work fine), you can find the rendering component at:
this.$slots.default[0].context;
Basically, the context property of a slot is the rendering context (rendering component - i.e. the component who's template the component was rendered in).
Only tested with Vue 2
I am trying to create fully reusable component using Vue.js 2 and single file components, and right now my approach seems to be impossible to realize.
The goal is to create component for creating forms for a complex, nested JSON structure. This structure is supposed to be edited and then sent to the server. The component itself displays a header and submit button but the fields along with their placing is entirely the responsibility of the user of my component. (front-end engineer)
The MyForm component (implementation is not relevant here) is passed the JSON data and url to post them to.
The form is supposed to be reusable by many other users and the contents of the form itself is supposed to be not relevant. It may have a mix of html/inputs/custom components as children.
Let's imagine a simple scenario without data nesting with the following data:
var mymodel={ name : "My name", surname : "My surname" }
And a form i would like to create using my component:
<MyForm :model="mymodel" :url="http://localhost/post">
<div>
<MyTextInput v-model="model.name" label="Name"/>
<MyPanel>
<MyTextInput v-model="model.surname" label="Surname"/>
</MyPanel>
</div>
</MyForm>
Therefore:
MyForm gets passed a model to submit, stores it in data
MyTextInput is a custom component for displaying input with label
Second MyTextInput is the same component but created in another component contained called 'MyPanel' since this field needs to be placed differently.
As we can see there are many problems with passing variables and composition itself:
Composition:
If i put a <slot></slot> in the tempplate of MyForm for displaying the fields it would be compiled in parent scope, therefore all children (including MyTextField) would not have access to the "model"
If i try to use <MyForm inline-template> i cannot automatically display the form header and footer since all content is being replaced. Additionally when using single file components the compiler will look for all components inside the inline-template which means that i would have to import MyTextInput and MyPanel into MyForm which is not practical. I do not know in advance all components that will never end up in my form!
Passing variables:
If i use the variables directly from "model" (in first TextInput) i receive warning that i am modifying a variable from parent and it will be overwritten on next render (but in this case it will not be overwritten since i am INTENTIONALLY modifying the parent)
I cannot pass the model into second MyTextInput without passing it to MyPanel first. Actually i would have to pass it into EVERY custom component in between. And i do not know in advance how many custom components will there be. Which means that i would have to modify the code of every component that would ever be put into MyForm and require users to pass the data for each custom component they include.
If i would try to properly inform the parent about changes i would need to add v-on: event to every textinput and every custom component in between in order for the event to reach MyForm.
As i have said the component was supposed to be simple and easilly reusable. Requiring users of this component to modify code of every child they put into it and requiring them to add v-on: to every component inside does not seem practical.
Is my idea solvable using Vue.js 2.0 ? I have designed the same component before for AngularJS (1.5) and it was working fine and did not require to add modifications to each child of the form.
I've been using a ui framework based on vue 2.0 and you may get some ideas from its implementation. Based on its implementaion and my little experience with it, I think it's the person who uses your framework's responsibility to assemble the form-model. Also, for a form, we can always easily get all the data to be sent by using fields' value props without v-model's help.
The framework's doc on form element may also be helpful but it's currently only available in Chinese except for the code samples.
I suggest you to use Form Input Components using Custom Events to pass variables in your form.
Mutating a prop locally is now considered an anti-pattern, e.g.
declaring a prop a and then set this.a = someOtherValue in the
component. Due to the new rendering mechanism, whenever the parent
component re-renders, the child component's local changes will be
overwritten. In general, in 2.0 you should treat props as immutable.
Most use cases of mutating a prop can be replaced by either a data
property or a computed property.