Can I get Vue.js component as an instance? - vue.js

I try to get the template of Vue.js component since I need it for another function.
First,
I have a function that needs a Vue.js component template because I want the data in the template to dynamically change and not just some static HTML.
Secondly,
I have a problem to get a template from Vue.js component. Maybe they are not allowed to do that but I am not sure. I am new to Vue.js.
But from my understanding of JS, maybe this can happen.
I am tried to do something like this:
let vmComponent = Vue.component('VueComponent', {
data() {
return {
title: 'I am a Vue.js component manually.'
}
},
template: `
<div>
<h2>Template Exchange</h2>
<h3>{{ title }}</h3>
</div>`,
});
console.log(vmComponent.template);
I hope to get the HTML string when I run vmComponent.template
If this way of doing things is not possible. Is there any other ways I can get Vue.js component template as HTML String.
For example, maybe in a new.Vue({})

It's possible to access component template with vmComponent.options.template.
A template can be declared as a string for reuse:
export const template = `...`;
const vmComponent = Vue.component('VueComponent', {
template,
...
});
This may not work with pre-compiled templates.

Related

Vue3 Reactivity in script setup for translation

I am adding some DOM elements in the script setup side but I want the messages to change when I change the language. I am using vue-i18n plugin. It's easy to do it in the template section because I can basically use the useI18n().t method but how can I do this in the script setup section. Using the useI18n().t method doesn't ensure reactivity.
Example Code:
$(".time")[0].innerHTML = `
<div>0<span>${useI18n().t("details.hour")}</span></div>
<div>0<span>${useI18n().t("details.minute")}</span></div>
<div>0<span>${useI18n().t("details.second")}</span></div>
`
Manipulating DOM directly inside the script leads to inconsistence in your app, you should drive your component by different reactive data to achieve your goal.
In your current situation try to define a computed property based on the translation then render it inside the template based on its different properties :
<script setup>
const {t} =useI18n()
const time = computed(()=>{
return {
hour:t(""details.hour"),
minute:t(""details.minute"),
second:t(""details.second"),
}
})
</script>
<template>
<div class="time">
<div>0<span>{{time.hour}}</span></div>
<div>0<span>{{time.minute}}</span></div>
<div>0<span>{{time.second}}</span></div>
</div>
</template>

Generate Vue Component with vanilla JS

I am currently using the bootstrap table component to display a list (bootstrap-table.com)
This component (or jQuery plugin wrapped within a vue component) has a formatter for each column.
example with source code: https://examples.bootstrap-table.com/#welcomes/vue-component.html#view-source
I need to build a more complex set of links which involve some js processing that could easily be done with vue.
Instead of the formatter returning the <a> tag I would like to return the contents of a <component>. I have tried this but haven't been able to render a component.
I'm almost sure this is impossible because the child component is not previously binded which means the component won't be "reactive".
As an alternative I can build a js function that generates all the required links.
Another phrasing for this question would be: Is there any possibility to generate a vue component from vanilla js?
The above was not possible the way was tried because the components cannot be simply rendered like html tags as they can have methods and computed data therefore they must be compiled.
It looks like the solution for the above situation is using the Vue.compile() method:
const template = `
<ul>
<li v-for="item in items">
{{ item }}
</li>
</ul>`;
const compiledTemplate = Vue.compile(template);
new Vue({
el: '#app',
data() {
return {
items: ['Item1', 'Item2']
}
},
render(createElement) {
return compiledTemplate.render.call(this, createElement);
}
});
Demo:
https://codepen.io/couellet/pen/ZZNXzy
Demo reference:
https://snipcart.com/blog/vue-render-functions
Vue docs:
https://v2.vuejs.org/v2/api/#Vue-compile

vue.js : click a button, look through dom, find all classes with a specific class name and append a new class to that existing class list

So, i'm using Axios to pull an html file, and then take everything in that html file past the <body> tag and appending it to {{htmlData}} inside of a div in my template
looks like this:
<template>
<somebutton> I click on</somebutton>
<div id="some-container-name" v-html="htmlData">
{{ htmlData }}
</div>
</template>
data: function() {
return {
htmlData:''
};
},
methods: {
pullView: function(html) {
this.axios.get('http://someUrl.html').then(response => {
let corsHTML = response.data;
let htmlDoc = (new DOMParser()).parseFromString(corsHTML, "text/html");
this.htmlData = htmlDoc.documentElement.getElementsByTagName('body')[0].innerHTML;
})
},
The user has an option to click on a button - the code then searches through the dom and then appends a classname to every existing you-can-edit-me class name from the html document that is pulled in via axios.
Does this make sense?
Because of how I'm pulling this content in, I don't really have the chance to bind anything to this content using Vue's :bind directive. My Google-fu has failed me and need some suggestions. Is it possible to edit this.htmlData and make the transformation in that object and then i guess re-render the data??
I don't want to pollute my work with jQuery and wondering if anyone else has done something like this?
Since you already have a parsed htmlDoc:
for (const element of htmlDoc.querySelectorAll('.you-can-edit-me')) {
element.classList.add('additional-css-class');
}
inside your pullView method, before assigning it to this.htmlData.

Dynamically insert child components inside vuejs2 data (without $compile or abusing v-html)

I'd like to insert new vuejs components on the fly, at arbitrary points within a block of not-necessarily-predefined HTML.
Here's a slightly contrived example that demonstrates the sort of thing I'm trying to do:
Vue.component('child', {
// pretend I do something useful
template: '<span>--><slot></slot><--</span>'
})
Vue.component('parent', {
data() {
return {
input: 'lorem',
text: '<p>Lorem ipsum dolor sit amet.</p><p><i>Lorem ipsum!</i></p>'
}
},
template: `<div>
Search: <input type='text' v-model="input"><br>
<hr>
This inserts the child component but doesn't render it
or the HTML:
<div>{{output}}</div>
<hr>
This renders the HTML but of course strips out the child component:
<div v-html="output"></div>
<hr>
(This is the child component, just to show that it's usable here:
<child>hello</child>)
<hr>
This is the goal: it renders both the input html
and the inserted child components:
TODO ¯\_(ツ)_/¯
</div>`,
computed: {
output() {
/* This is the wrong approach; what do I replace it with? */
var out = this.text;
if (this.input) {
this.input = this.input.replace(/[^a-zA-Z\s]/g,'');
var regex = new RegExp(this.input, "gi");
out = out.replace(regex, '<child><b>' + this.input + '</b></child>');
}
return out;
}
}
});
new Vue({
el: '#app'
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.3.0/vue.js"></script>
<div id="app">
<parent></parent>
</div>
In the above snippet, assume data.text is sanitized HTML. <child> is some sub-component that does something useful, which I want to wrap around chunks of data.text that aren't known ahead of time. (input is just for demo here. This MCVE doesn't really resemble the code I'm building, it's just an example that shows the sort of situation I'm stuck on.)
So: how would I change either the output function or the parent component's template, such that both the HTML from input and the inserted <child> templates are rendered properly?
What I've tried
In Vue 1, the answer to this would be a straightforward $compile. I'm using vuejs2 which removed $compile (out of justifiable concern that it made it too easy to naively introduce XSS vulnerabilities.)
v-html sanitizes what you feed it, which strips the child component out. Obviously this is not the way to do this. (That page suggests using partials instead, but I'm not sure how that could be applied to this situation; in any case partials have also been removed from vue2.)
I've tried passing the results of output() into another component which would then use it as its template. This seems like a promising approach, but I can't figure out how to change that secondary component's template. template only accepts a string, not a function like many of the other component properties, so I can't pass the template html in, say, a prop. Something like rewriting this.template inside beforeMount() or bind() would have been nice, but no joy there either. Is there some other way to replace a component's template string before it's mounted?
Unlike template, I can pass data to a component's render() function... but then I'm still stuck having to parse that html string into nested createElement functions. Which is exactly what Vue is doing internally in the first place; is there some way to hook into that here short of reinventing it myself?
Vue.component('foo', {
props: ['myInput'],
render(createElement) {
console.log(this.myInput); // this works...
// ...but how to parse the html in this.myInput into a usable render function?
// return createElement('div', this.myInput);
},
})
I wasn't able to cheat my around this with inline-template, either: <foo inline-template>{{$parent.output}}</foo> does exactly the same thing as a plain old {{output}}. In retrospect that should have been obvious, but it was worth a shot.
Maybe constructing an async component on the fly is the answer? This could clearly generate a component with an arbitrary template, but how would I reasonably call that from the parent component, and feed output to the constructor? (It would need to be reusable with different input, with multiple instances potentially visible simultaneously; no globals or singletons.)
I've even considered ridiculous stuff like having output() split the input into an array at the points where it would have inserted <child>, and then doing something like this in the main template:
...
<template v-for="chunk in output">
<span v-html="chunk"></span>
<child>...</child>
</template>
....
That would be doable, if laborious -- I'd have to split out what goes in the child's slot into a separate array too and get it by index during the v-for, but that could be done... if input were plain text instead of HTML. In splitting HTML I'll often wind up with unbalanced tags in each chunk, which can mess up the formatting when v-html rebalances it for me. And anyway this whole strategy feels like a bad hack; there must be a better way.
Maybe I just drop the whole input into a v-html and then (somehow) insert the child components at the proper positions through after-the-fact DOM manipulation? I haven't explored this option too deeply because it, too, feels like a hack, and the reverse of the data-driven strategy, but maybe it's a way to go if all else fails?
A couple of pre-emptive disclaimers
I'm very well aware of the XSS risks involved in $compile-like operations. Please be assured that none of what I'm doing involves unsanitized user input in any way; the user isn't inserting arbitrary component code, instead a component needs to insert child components at user-defined positions.
I'm reasonably confident that this is not an XY problem, that I really do need to insert components on the fly. (I hope it's obvious from the number of failed attempts and blind alleys I've run down that I've put more than a little thought into this one!) That said, if there's a different approach that leads to similar results, I'm all ears. The salient point is that I know which component I need to add, but I can't know ahead of time where to add it; that decision happens at run time.
If it's relevant, in real life I'm using the single-file component structure from vue-cli webpack template, not Vue.component() as in the samples above. Answers that don't stray too far from that structure are preferred, though anything that works will work.
Progress!
#BertEvans points out in comments that Vue.compile() is a thing that exists, which is an I-can't-believe-I-missed-that if ever there was one.
But I'm still having trouble using it without resorting to global variables as in that documentation. This renders, but hardcodes the template in a global:
var precompiled = Vue.compile('<span><child>test</child></span>');
Vue.component('test', {
render: precompiled.render,
staticRenderFns: precompiled.staticRenderFns
});
But various attempts to rejigger that into something that can accept an input property have been unsuccessful (the following for example throws "Error in render function: ReferenceError: _c is not defined", I assume because the staticRenderFns aren't ready to go when render needs them?
Vue.component('test', {
props: ['input'],
render() { return Vue.compile(this.input).render()},
staticRenderFns() {return Vue.compile(this.input).staticRenderFns()}
});
(It's not because there are two separate compile()s -- doing the precompile inside beforeMount() and then returning its render and staticRenderFns throws the same error.)
This really feels like it's on the right track but I'm just stuck on a dumb syntax error or the like...
As mentioned in the my comment above, $compile was removed, but Vue.compile is available in certain builds. Using that below works as I believe you intend except in a couple cases.
Vue.component('child', {
// pretend I do something useful
template: '<span>--><slot></slot><--</span>'
})
Vue.component('parent', {
data() {
return {
input: 'lorem',
text: '<div><p>Lorem ipsum dolor sit amet.</p><p><i>Lorem ipsum!</i></p></div>'
}
},
template: `<div>
Search: <input type='text' v-model="input"><br>
<hr>
<div><component :is="output"></component></div>
</div>`,
computed: {
output() {
if (!this.input)
return Vue.compile(this.text)
/* This is the wrong approach; what do I replace it with? */
var out = this.text;
if (this.input) {
this.input = this.input.replace(/[^a-zA-Z\s]/g,'');
var regex = new RegExp(this.input, "gi");
out = out.replace(regex, '<child><b>' + this.input + '</b></child>');
out = Vue.compile(out)
}
return out;
}
}
});
new Vue({
el: '#app'
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.3.0/vue.js"></script>
<div id="app">
<parent></parent>
</div>
You mentioned you are building with webpack and I believe the default for that build is Vue without the compiler, so you would need to modify it to use a different build.
I added a dynamic component to accept the results of the compiled output.
The sample text is not a valid template because it has more than one root. I added a wrapping div to make it a valid template.
One note: this will fail if the search term matches all or part of any of the HTML tags in the text. For example, if you enter "i", or "di" or "p" the results will not be what you expect and certain combinations will throw an error on compilation.
I'm posting this as a supplement to Bert Evans's answer, for the benefit of vue-cli webpack users who want to use .vue files instead of Vue.component(). (Which is to say, I'm mostly posting this so I'll be able to find this information when I inevitably forget it...)
Getting the right Vue build
In vue-cli 2 (and possibly 1?), to ensure Vue.compile will be available in the distribution build, confirm webpack.base.conf.js contains this line:
'vue$': 'vue/dist/vue.esm.js' // or vue/dist/vue.common.js for webpack1
instead of 'vue/dist/vue.runtime.esm.js'. (If you accepted the defaults when running vue init webpack you will already have the full standalone build. The "webpack-simple" template also sets the full standalone build.)
Vue-cli 3 works somewhat differently, and does not have Vue.compile available by default; here you'll need to add the runtimeCompiler rule to vue.config.js:
module.exports = {
/* (other config here) */
runtimeCompiler: true
};
The component
The "child" component can be a normal .vue file, nothing special about that.
A bare-bones version of the "parent" component would be:
<template>
<component :is="output"></component>
</template>
<script>
import Vue from 'vue';
import Child from './Child'; // normal .vue component import
export default {
name: 'Parent',
computed: {
output() {
var input = "<span>Arbitrary single-root HTML string that depends on <child></child>. This can come from anywhere; don't use unsanitized user input though...</span>";
var ret = Vue.compile(input);
ret.components = { Child }; // add any other necessary properties similarly
ret.methods = { /* ... */ } // like so
return ret;
}
}
};
</script>
(The only significant difference between this and the non-webpack version is importing the child, then declaring the component dependencies as ret.components: {Child} before returning it.)

vuejs 2 how to add child component without npm

I use vuejs2 and want to attach some component to my main one. Now I can have something like this:
var Component ={
template: '<div>1</div>'
};
However, I want the thing in template to be a partial html from some other directory, like template:'../../com/a.html', I heard x-template but not know how to use it. Also, is there some lib other than webpack/browserify/npm series I can use directly just by add the script in the end of html?
You have your template file as
/* yourPath/name.template.html */
<div class="myClass">
1
</div>
Then in the component file, you can do following:
export default {
template: require('yourRelativePath/name.template.html'),
data: function () {
return {
};
}
}