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 am using Nuxt.js / Vuejs for my app, and I keep facing this error in different places:
The client-side rendered virtual DOM tree is not matching server-rendered content.
This is likely caused by incorrect HTML markup, for example nesting block-level elements inside <p>, or missing <tbody>.
Bailing hydration and performing full client-side render.
I would like to understand what is the best way to debug this error? Is their a way I can record/get the virtual DOM tree for client and server so I could compare and find where the error lies?
Mine is a large application and manually verifying is difficult.
Partial answer: with Chrome DevTools, you can localize the issue and see exactly what element caused the issue. Do the following (I did that with Nuxt 5.6.0 and Chrome 64.0.3282.186)
Show DevTools in Chrome (F12)
Load the page that causes "the client-side rendered virtual DOM tree..." warning.
Scroll to the warning in DevTools console.
Click at the source location hyperlink of the warning (in my case it was vue.runtime.esm.js:574).
Set a breakpoint there (left-clicking at line number in the source code browser).
Make the same warning to appear again. I'm not saying it is always possible, but in my case I simply reloaded the page. If there are many warnings, you can check the message by moving a mouse over msg variable.
When you found your message and stopped on a breakpoint, look at the call stack. Click one frame down to call to "patch" to open its source. Hover mouse over hydrate function call 4 lines above the execution line in patch. Hyperlink to the source of hydrate would open.
In the hydrate function, move about 15 lines from the start and set a breakpoint where false is returned after assertNodeMatch returned false. Set the breakpoint there and remove all other breakpoints.
Make the same warning to happen again. Now, when breakpoint is hit, execution should stop in the hydrate function. Switch to DevTools console and evaluate elm and then vnode. Here elm seem to be a server-rendered DOM element while vnode is a virtual DOM node. Elm is printed as HTML so you can figure out where the error happened.
For me this error happened cuz get Array list in AsyncData and rendered <tr> tags by v-for, i put v-for codes in <client-only> blocks and problem solved
This error can be really painfull to debug. In order to quickly get the element causing an issue edit node_modules/vue/dist/vue.esm.js and add the following lines :
// Search for this line:
function hydrate (elm, vnode, insertedVnodeQueue, inVPre) {
var i;
var tag = vnode.tag;
var data = vnode.data;
var children = vnode.children;
inVPre = inVPre || (data && data.pre);
vnode.elm = elm;
// Add the following lines:
console.log('elm', elm)
console.log('vnode', vnode)
console.log('inVpre', inVPre)
// ...
You will get in the console the failing node.
There are a lot of ways of fixing this issue, but most of them are not actual fixes, just hacky band-aids. To note a few:
wrap it into <client-only> tags, beware of some important details tho
using a v-show instead of a v-if
trying to hack some lifecycles
etc...
I highly recommend reading this gorgeous article written by Alexander Lichter
https://blog.lichter.io/posts/vue-hydration-error/
He'll explain you that you should diagnose why this happens and fix the actual issue.
Basically each time something is different from what was generated on the server and what is available when done hydrating on the client will cause this error.
Some of which are:
invalid HTML (having a block element inside of a <p>, same goes for an a tag nested into another, etc...)
3rd party scripts messing around with your components
different state on server vs client
any random is risky (new Date() for example)
any page related to authentication
I highly recommend reading the article to understand in Alexandre's own words how to handle this kind of issue. If you're in a hurry you could always use one band-aid fix but try to actually fix the issue for the best performance and to keep the code clean.
I had the same issue as of nuxt version 2.14.0 while implementing vue-particles package. The fix was to surround the tags with no-ssr and it fixed the issue.
EDIT:
Updated variant of the solution (if Nuxt version is above 2.9.0)
<client-only>
<vue-particles>
</vue-particles>
</client-only>
Old solution:
<no-ssr>
<vue-particles>
</vue-particles>
</no-ssr>
Thanks to budden73's answer, I did a little improvement on the debug process.
Open dev tool
click on the warn message, and click on the first line of the warn message, you will be directed to the Sources panel, with a file name vue.runtime.esm.js?xxxx
ctrl+f to search the above file for assertNodeMatch, not the function, but like:
if (process.env.NODE_ENV !== 'production') {
if (!assertNodeMatch(elm, vnode, inVPre)) {
return false
}
}
Add a break point at the line return false
Refresh the page, and the breakpoint will be triggered.
At the right side of the Sources panel, Under Scope->Local, click on the elm element, you will be directed back to the Elements panel.
The above element is the client side rendered element, compare with your code to see the difference.
If you can't find the source of the bug, the brutal way to fix it is using nuxt's <client-only> tag.
Another likely brutal way is described here. Add an isHydrate variable which default is false, set to true in mounted hook, and render the element after the variable set to true.
For Nuxt version above 2.10 it doesn't need to install nothing, just use the default component <client-only> as mentioned https://nuxtjs.org/api/components-client-only/.
Check the previous warning:
In "nuxt": "^2.12.2", You can spot the cause easily from the previous warning.
In my case:
Incorrect
<nuxt-link to="/game42day">
<a>Game For Today</a>
</nuxt-link>
Correct:
<nuxt-link to="/game42day">
Game For Today
</nuxt-link>
If you're rendering a component conditionally with v-if, then you have two options to solve the problem:
The first one is wrapping the element in <no-ssr></no-ssr> tag.
The second approach is replacing v-if with v-show, here is the link to Vue docs.
Turns out, in my case, I had HTML comment tags , which was causing this stupid, annoying error. Took me too long to figure it out but in case it helps someone.
In my case I had to change this:
<v-expansion-panel-header v-text="name" />
to this:
<v-expansion-panel-header>{{ name }}</v-expansion-panel-header>
I also get many errors due to this problem. I list two cases I often encounter, hope can help you.
With vuetify button, when you create a common component, you should use: <v-btn>{{text}}</v-btn>. Example:
<template>
<v-btn
:width="width"
:color="color"
:class="[rounded ? 'rounded-pill' : 'rounded-lg',textColor]"
v-on:click="onClick"
elevation="0"
:outlined="outlined"
:type="type"
:name="name"
:form="form"
:disabled="disabled"
v-bind="$attrs"
>{{ text }}</v-btn>
</template>
Don't use v-html with <p> tag.
Not use: <p v-html='html'></p>.
Use: <div v-html='html'></div>.
Besides, if you use <client-only></client-only>, this problem is definitely solved, but if you need to SEO page or show google ads, it is not good solution.
Ok this is going to sound silly. I tried a bunch of different solutions for about 15 mins such as restarting the server and deleting the .nuxt directory but I was too lazy to use #budden73's big brain solution. What ended up working for me was simply restarting my computer, give it a shot.
What I have found so far from observation is that when you are using third party packages like jQuery (specially), they sometimes inject html tags into the dom. So Vue/Nuxt looses track of the dom tree and starts complaining.
I was having the same problem and after a while I removed all jQuery and replaced jQuery functionality with Vuejs and those error were all gone.
See here for an example of how to deal with integrations (e.g. Google Analytics or FB Pixel) that modify the DOM. Basically create a plugin and exclude from SSR.
https://nuxtjs.org/faq/ga
What about:
extend (config, ctx) {
config.resolve.symlinks = false
}
See this [Vue warn]: The client-side rendered virtual DOM tree is not matching server-rendered content ( Nuxt / Vue / lerna monorepo )
Now that you found the code causing the problem, the first thing you should do is to verify that your markup (possibly coming from an API) is valid. Code like <p><p>Text</p></p> is not valid because a p element doesn’t allow other block elements (like a paragraph tag) inside.
Be aware, that tags are not allowed to have block level elements like <div> or <p> as children. These <span> tags are used default tag for Vue’s transitions though. You can change that though via <Transition tag="div">.
Check if have used any block-level element inside the inline element.
for example: inside , inside
If you have used an HTML table make sure you have used the tag
In my case, I changed my codes from
<p v-html="$md.render(post.content)"></p>
to
<p>{{ $md.render(post.content) }}</p>
In my case this problem was caused by markdownit module, I solved it by changing the html markup used with v-html. I was with <p> at the beginning and I ended with <div>.
I have some <p> in my v-html render (with $md.render()) so take care if you have same problems with different markups.
I am trying to use a <b-form-datepicker> in a vuejs application.
Browser tells me the error:
[Vue warn]: Unknown custom element: <b-form-datepicker> - did you register the component correctly? For recursive components, make sure to provide the "name" option.
I am using other bootstrap-vue compoments without problems.
Giving it a 'name' property does not change a thing.
What am I missing here?
The documentation on https://bootstrap-vue.org/docs/components/form-datepicker does not talk about registering any components. (Did I miss a basic fundamental patr when and how to use components?)
I am using the template-script-style pattern for building this part of the gui.
In my main.js Í do have a declaration of import BootstrapVue from 'bootstrap-vue';
On other locations using bootstrap-vue elements it works out of the box as far as I have seen.
Somewhat nearest other issue about that for me was https://stackoverflow.com/a/51410592/845117.
But there I am missing the link of the documentation of naming components as well as the import statement with the 'custom' path: import { Alert } from 'bootstrap-vue/es/components';
Did I miss a major part? What is the missing link here for me?
#Hiws is absolutely right.
The deal was with the version. I am missing the experience with the npm system.
Thank you!
I am using Vue.js in an app, but only for parts that require more logic. Otherwise I stick with Web components.
I hit an issue when I am try to mix those. I have a Web Component that only extends an existing element (input in my case). Without Vue.js everything works as expected, but inside Vue, "is" is a Vue attribute (docs) and thus entire element is converted to a name element as specified there.
To give an example, HTML without Vue.js stays as is:
<input type="text" is="test-autocomplete" name="search" />
But with Vue.js, it becomes:
<test-autocomplete type="text" name="search"></test-autocomplete>
Which is wrong. It should stay the same as in first case.
Searching on the web, the only solution I found is to set ignored elements as:
Vue.config.ignoredElements = [
'test-autocomplete',
/^test-/
];
But it does not work and here is where I started running out of ideas. Any help from this point how to make it work is appreciated!
I created a minimum fiddle, where my issue is reproduced. I'd expect both outputs to render identically.
https://jsfiddle.net/q2cre9po/2/
I struggle to understand the component and template system in VueJS. I downloaded the VuetifyJS PWA example template and tried to replace the complete content of Hello.vue with the content of the VuetifyJS google-contacts.vue example template.
I got this error message after npm run dev on localhost:8080:
> vue.esm.js?65d7:578 [Vue warn]: Failed to mount component: template or render function not defined.
found in
---> <Hello> at /home/a/my-project/src/components/Hello.vue
<App> at /home/a/my-project/src/App.vue
<Root>
Why is it not possible to just replace the <template></template> content and what do I need to change to use the google-contacts.vue template content instead of the Hello.vue content?
I just followed the process and it works ok for me, so I'm guessing it's most likely a miss-step in your build, but so far can't reproduce it.
Note, it looks like docs/examples/layouts/google-contacts.vue is a replacement for the overall page layout rather than an individual component (thinking along the lines #B.Fleming mentions in comments), so it's more appropriate to replace App.vue than Hello.vue.
This is what I originally did (not reading your post thoroughly). But subsequently replacing Hello.vue gives me the same working Google Contacts page.