I'm using quasar and vue3 to build an SSR app
In chrome developer mode when I visualize the generated HTML, I have some Vue components not compiled to raw HTML like:
<body class="desktop body--light" data-server-rendered>
<div v-for="deal in clientssList" :key="client.Id">
<CLientItemSmDown :ClientModel="deal"></CLientItemSmDown>
</div>
is this normal, isn't SSR supposed to return raw HTML so bots can read it?
Saw this question last time already (can't find it back).
But no, CLientItemSmDown is a valid web-component and don't need to be transformed into a built-in HTML tag like input, div etc...
There is maybe an option to convert it down the road to some HTML, but I don't think that it's necessary and it may not be easily done if it's not supported by default.
That page may be quite interesting regarding Vue + Web-components.
You may raise a Github issue or join their Discord.
The TLDR being that it's fine to let it as is IMO.
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.
In a Vue.js project I am using learning to use Modals from BootstrapVue. In my code I have a file Items.vue with something like this:
<div v-b-modal="'modal-' + query.id"> // this is line 15
...
</div>
<b-modal :id="'modal-' + query.id">
<p class="my-4">
hello
</p>
</b-modal>
It works well. However, Intellij IDEA with the Vue.js plugin keeps beeping with the Warning:
Warning:(15, 5) Attribute v-b-modal is not allowed here
The thread Vue Attribute is not allowed here suggests that this happens with non-.vue files, but it is not the case here.
Replacing v-b-modal="..." with :v-b-modal="..." (that is, with : before the attribute to make the binding more explicit) removes the warning, but then the code does not work.
I am working with Intellij IDEA 2018.1.8.
IDEA version you are using is very old, Vue.js support has been significantly improved since v. 2018.1. In particular, WEB-38028 was fixed in 2019.2. Please consider upgrading IDEA to the most recent version, BootstrapVue directives are correctly recognized there
I have my
v-html="customButtons"
and I want to insert in this v-html a v-on:click with custom function like this
<div class="v-m-button">
<button type="button" id="btn-cancel" class="btn btn-sm btn-success"
v-on:click="saveButtonClick()">
<span>Save</span>
</button>
</div>
^code above will be pass to customButtons v-html tag
help me with this thanks!
I ran into the same issue and here are the solutions I found:
On Vue 2, there is this article that might help some people: https://www.programmersought.com/article/53615036178/
On Vue 3, there is this library over there, that I used with success.
However, as mentioned by others elsewhere there are a good reasons why this is made so hard to do. Maybe the security reasons are not a big concern for you. But say that your app grows and is so widely used that performance becomes your main concern; then you may want to rebuild your front-end using Svelte instead of Vue. Then, all your #click=this... (vue specific code) in the html sent by you API will become almost unusable by the Svelte app, at which point you might tell to yourself:
"It would have been way simpler to just send those as json metadata and build the appropriate interface instead of trying to 'win time' by brute-forcingly favoring a bad data structure."
I'm using both Vue.js and HAML in my current project. The templates are parsed by HAML, converted into HTML, then parsed by Vue. For instance:
#pagecontent.nonscrolling
%h2 Demand forecasts
%label{ for:"location-type" } Select location type
%select.form-control#location-type{ v-model:"locationType" }
%option{ v-bind:value:"'foo'" } Foo
It works ok, but it's a bit disconcerting worrying whether all the Vue syntax will make it unscathed through the HAML parser.
But I really like this type of succinct, angle-bracket-less template.
Is there is a cleaner way to achieve this? Some add-on to Vue that supports something similar?
Don't worry to much. There is nothing wrong about using preprocessors. I mean vue depends on wepback where everything is being preprocessed in one way or an other. Out of the box you can use pug with vue so I put more trust in it. It works fine for me without any unexpected problems. Both have the nesting through indentation in common and this is something that starts to be confusing with longer source codes. So I use pug mainly in short components and nest them using named slots into bigger ones.
Your code - pug version (as far I can guess what this HAML code should do)
<template lang="pug">
#pagecontent.nonscrolling
h2 Demand forecasts
label(for="location-type") Select location type
select.form-control#location-type(v-model="locationType")
option(v-bind:value="foo") Foo
</template>
The whole Vuetifyjs website is made with pug:
Vuetifyjs.com Source Code