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'm hoping someone with a better understanding of AngularJS might be able to shed some light on whats going on here.
I have a webpage with a long form. After the JS form plugin is initialized, everything in the form no longer has two way data binding. JS plugin for reference can be found here
If I remove the id link to the JS plugin, thus not applying or rendering the steps plugin, all two way data binding works as expected.
I could post a lot of code here but I'm not sure that would help. I have no problem posting code at any request.
Any ideas on why the two way data binding is losing effect after rerendering a form tag and its contents?
I was actually able to get AngularJS to work correctly with this plugin by including the plugin at the bottom of the page instead of the top. So I think the key here was to let AngularJS load up first, then the page, then the jQuery Steps plugin (at the boom of the page that uses it).
Thanks all for your comments!
Jquery library should include before angular library otherwise your site will try to use jquery instead of angular own lite jquery which will definitely break the binding.
Accompanying jsFiddle with reproduction of problem: http://jsfiddle.net/ComradeF/M9e94/
I am using Foundation and Knockout together on a project. One of the challenges I faced was that when new tabs needed to be rendered, Knockout would comply, but clicking the tabs wouldn't do anything. The solution to that was a call to $(document).foundation('reflow') in a custom binding. Unfortunately, that solution may be either insufficient or just plain wrong, as it is now associated with an error I am receiving.
I tried to add tooltips to the tabs and some of their content via the data-tooltip attribute in my markup, only to get errors on line 1422 of jQuery 2.1.0. That line is elem.getAttribute( name ), and the error is undefined is not a function. In this situation, elem is a comment, and thus has no getAttribute() function.
The error can be eliminated either by removing the comment (<!-- this is a comment -->) in the markup, or by removing the data-tooltip attribute in the tab's link.
I realize the quick fix is for me to remove the HTML comments from my markup, but I feel like this may be a symptom of something worse lurking... so I'd prefer to investigate and solve rather than take the easy way out.
I have come across the same problem (except I am working on an Angular js project).
I have not been able to find a solution yet but I have found a work around. If anyone knows a good solution please let me know.
My work around was to reduce the scope of the $(document).foundation('reflow'); to avoid any html comments elements (which are unfortunately necessary and common in Angular js apps).
e.g. $(element.find("nav")).foundation('tooltip', 'reflow'); This at least stops the errors happening in my specific use case.
I tried fixing this using sacumminis's solution - that removed the exception but it also made my tooltips stop working.
However this thread had a solution by Ayush Gupta which worked perfectly. I'm using this with Angular rather than Knockout so I simply put it early in my app.js file. What you need to do is add this chunk of code somewhere early in your app code:
Object.getPrototypeOf(document.createComment('')).getAttribute = function() {}
The error is now gone and tooltips work well. Hope it helps someone.
What I want is each of tab consist of its dynamic content, but now I doubt I was doing it correctly when I put ng-view within ng-repeat.
Here is a working version to push http://plnkr.co/edit/19sAXoEW4HZ9G7CT7R3a?p=preview . So in the beginning it was fine for me.
But after that I felt I've to load some data, the tab no longer working working when I do $scope.tasks = tasks
which tasks is a object in data.js. Here is the error : http://plnkr.co/edit/jbxypSlvk3rYlFAIHygo?p=preview
You are missing quotes on active=tab.active change to active="tab.active".
Which causes the
Error: The string contains invalid characters.
Why are you shoe-horning tabs here. I think a simple nav would do. The underlying issue is your design is fundamentally flawed, you can only have one ng-view on a page. If you update your post I can recommend a solution.
I am using the view helper multiple times, in order to render the same template but with different parameters every time, mostly booleans acting as option flags.
However, I get the following error, whenever I render more than 1 of the same view:
Assertion failed: Attempted to register a view with an id already in use: null
My element tags do not have an "ember id", e.g. id="ember224".
I replicated the issue in a JSBin:
Please note that in JSBin you won't be able to see the error logged in the console, for
whatever reason. A simple copy and paste over to
http://www.embersandbox.com/ and you can open up the console and see
the error itself.
http://jsbin.com/UHOh/1/edit?html,js,output
Does anyone have any idea why this happens? If so, could it be a problem? Everything else is working as it should, for now, so I am inclined to ignore it.
Thanks!
You are overriding the init() method of Ember.View and not calling this._super(). This causes the view to not initialize properly resulting in your view elements missing id attributes (e.g. id="ember224").
Below is a link to your original JSBin with the addition of MyCustomView.init() calling this._super(). You will find the view elements now have id attributes.
http://jsbin.com/UHOh/11/edit?html,js,output