Prevent vue render newline between elements - vue.js

<template>
<div>
<span>foo</span> <!-- unwanted space here -->
<span>bar</span>
<span>foo</span>
</div>
</template>
// But I don't want to do this
<template>
<div>
<span>
foo
</span><span> <!-- bad coding style -->
bar
</span><span>
baz
</span>
</div>
</template>
In html, newlines between elements are rendered as spaces, and Vue followed that behavior. If I want no spaces between the elements, the obvious way is to put no space there, as shown in the code sample. But it is ugly, I don't want that. How can I do otherwise such that there is no space between the elements?

You can change the compiler options.
compilerOptions
type: Object
default: {}
Options for the template compiler. When using the default vue-template-compiler, you can use this option to add custom compiler directives, modules, or discard whitespaces between template tags with { preserveWhitespace: false }.
However the documentation states this only applies to single file components and template tags. I don't think there is currently any option for native tags and related issue has been closed. But maybe it gives you the desired result.

Related

v-else is getting rendered first instead v-if in Vue JS

I have an HTML element like below
<div v-if="showOriginalContent"> original content</div>
<div v-else> default content </div>
initial value of showOriginalContent is false
and from mounted method am calling an another method where i will make the value of showOriginalContent to true based on some conditions . Currently even if the showOriginalContent is true i can see that v-else is getting displayed for a fraction of seconds before v-if is rendered in the DOM . How can i solve this issue ? I tried to move the function call to all other life cycle methods but nothing is working . I have gone through before and after navigation approach in vue js ,Is it possible to apply that logic here?
I think it's normal if I understood correctly what you posed as the problem.
Because the mounted state is called when the view has already been OK and displayed and only once.
So a variable declaring in this method its change will not necessarily have an effect on what should be displayed.
Try to see the lifecycle in Vuejs for more detail.
Put it in computed or watch methods to see.
Use an outer div and control this div with another variable that will be true when you are done with your condition parts in mounted hook.. like this..
<div v-if="conditioncheckdone">
<div v-if="showOriginalContent"> original content</div>
<div v-else> default content </div>
</div>
It will resolve your issue of displaying v-else stuff while you are checking your conditions in mounted
turn the default showOriginalContent value to null instead of false

Vue slots with variable HTML passed in

I have a string that contains some HTML markup.
I would like to pass this into a component's slot.
This component is used elsewhere with regular html markup between the opening and closing tags, and works as expected.
The issues are that mustache syntax outputs escaped HTML, {{myFormattedText}} becomes literally Some line of <span>text with formatting</span> that is passed in from somewhere else which is not what we want.
Passing it in the v-html="myFormattedText" attribute on the component replaces all content inside the component tags with the variable string.
Is there a way to do this? I'd like to reuse this component, for visual consistency reasons, but the content that we receive for it is disparate and varies widely based on the view or source.
Test string:
myFormattedText = "Some line of <span>text with formatting</span> that is passed in from somewhere else";
Component:
<template>
<div class="doing-a-thing">
<h2>Some text</h2>
<div class="thing">Random stuff</div>
<slot></slot>
</div>
</template>
Attempts:
<mycomponent>{{myFormattedText}}</mycomponent>
<mycomponent v-html="myFormattedText"></mycomponent>
Just put the v-html render on an element inside the component tags and it'll get rendered correctly and passed in.
<mycomponent><div v-html="myFormattedText"></div></mycomponent>
Again, moments after posting, it hits me like a bolt of lightning...

prevent paper-listbox selection change

I got a paper-listbox containing a paper-checkbox contained within each paper-item of the list.
<paper-listbox id="groupMembers" multi attr-for-selected="label">
<template is="dom-repeat" items="[[users]]" as="member">
<paper-item label="[[member.user]]">
<span class="member-user">[[member.user]]</span>
<paper-checkbox checked="[[member.isManager]]"></paper-checkbox>
</paper-item>
</template>
</paper-listbox>
Whenever the checkbox is clicked it also changes the selected state of the listbox items resulting in an paper-item becoming selected or deselected.
How can that be prevented?
paper-listbox uses Polymer.IronSelectableBehavior and Polymer.IronMultiSelectableBehavior. So, you can use selectable attribute in order to prevent changing the selected state.
selectable is a CSS selector string. If this is set, only items that match the CSS selector are selectable. You can put a random string so that it won't match the paper-item element.
Demo
i solved the problem by avoiding it ;)
Moved the checkbox out of the paper-item into the dom-repeat like so:
<paper-listbox id="groupMembers" multi attr-for-selected="label">
<template is="dom-repeat" items="[[users]]" as="member">
<paper-item label="[[member.user]]">
<span class="member-user">[[member.user]]</span>
</paper-item>
<div class="checkWrapper">
<paper-checkbox checked="[[member.isManager]]"></paper-checkbox>
</div>
</template>
</paper-listbox>
With a bit of CSS positioning magic that works. Added a wrapper div to allow absolute positioning.

Change element type at runtime

Is it possible to dynamically define the type of an element inside a custom components template at runtime?
I'd like to avoid duplication of the inner contents of the button and a element in the following example:
<template>
<button if.bind="!isLinkBtn">
<span class="btn-icon">${icon}</span>
<span class="btn-text">${contentText}</span>
</button>
<a if.bind="isLinkBtn">
<!--
The content is a 1:1 duplicate of the button above which should be prevented
somehow in order to keep the view DRY
-->
<span class="btn-icon">${icon}</span>
<span class="btn-text">${contentText}</span>
</a>
</template>
Is it possible to write something like this:
<template>
<!--
The type of element should be defined at runtime and can be a standard HTML "button"
or an anchor "a"
-->
<element type.bind="${isLinkBtn ? 'a' : 'button'}">
<span class="btn-icon">${icon}</span>
<span class="btn-text">${contentText}</span>
</element>
</template>
I'm aware of dynamic composition with <compose view="${widget.type}-view.html"></compose> but as far as I know, this won't allow me to create default HTML elements but only custom components, correct?
I've asked this question on the Aurelia Gitter where Erik Lieben suggested to use a #processContent(function) decorator, replace the content within the given function and return true to let Aurelia process it.
Unfortunately I don't know how to actually apply those instructions and am hoping for some alternative approaches here or some details about how to actually accomplish this.
Edit
I've created a corresponding feature request. Even though possible solutions have been provided, I'd love to see some simpler way to solve this ;)
When you want to reuse HTML snippets, use compose. Doing so does not create a new custom element. It simply includes the HTML at the location of each compose element. As such, the view-model for the included HTML is the same as for the element into which it is composed.
Take a look at this GistRun: https://gist.run/?id=36cf2435d39910ff709de05e5e1bedaf
custom-link.html
<template>
<button if.bind="!isLinkBtn">
<compose view="./custom-link-icon-and-text.html"></compose>
</button>
<a if.bind="isLinkBtn" href="#">
<compose view="./custom-link-icon-and-text.html"></compose>
</a>
</template>
custom-link.js
import {bindable} from 'aurelia-framework';
export class CustomLink {
#bindable() contentText;
#bindable() icon;
#bindable() isLinkBtn;
}
custom-link-icon-and-text.html
<template>
<span class="btn-icon">${icon}</span>
<span class="btn-text">${contentText}</span>
</template>
consumer.html
<template>
<require from="./custom-link"></require>
<custom-link content-text="Here is a button"></custom-link>
<custom-link is-link-btn.bind="true" content-text="Here is a link"></custom-link>
</template>
You may want to split these into separate elements, like <custom-button> and <custom-link> instead of controlling their presentation using an is-link-btn attribute. You can use the same technique to reuse common HTML parts and composition with decorators to reuse the common code.
See this GistRun: https://gist.run/?id=e9572ad27cb61f16c529fb9425107a10
Response to your "less verbose" comment
You can get it down to one file and avoid compose using the techniques in the above GistRun and the inlineView decorator:
See this GistRun: https://gist.run/?id=4e325771c63d752ef1712c6d949313ce
All you would need is this one file:
custom-links.js
import {bindable, inlineView} from 'aurelia-framework';
function customLinkElement() {
return function(target) {
bindable('contentText')(target);
bindable('icon')(target);
}
}
const tagTypes = {button: 'button', link: 'a'};
#inlineView(viewHtml(tagTypes.button))
#customLinkElement()
export class CustomButton {
}
#inlineView(viewHtml(tagTypes.link))
#customLinkElement()
export class CustomLink {
}
function viewHtml(tagType) {
let result = `
<template>
<${tagType}${tagType === tagTypes.link ? ' href="#"' : ''}>
<span class="btn-icon">\${icon}</span>
<span class="btn-text">\${contentText}</span>
</${tagType}>
</template>
`;
return result;
}
Sorry, I was doing 2 things at once while looking at gitter, which I am not good at apparently :-)
For the thing you wanted to accomplish in the end, could this also work?
I am not an a11y expert or have a lot of knowledge on that area, but from what I understand, this will accomplish what you want. The browser will look at the role attribute and handle it as a link or button and ignores the actual element type itself / won't care if it is button or anchor it will act as if it is of the type defined in role.
Then you can style it like a button or link tag with css.
<a role.bind="type"><span>x</span><span>y</span></a>
where type is either link or button, see this: https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Techniques/Using_the_link_role

vue.js - Change text based on default/clicked class

Given the following:
<div id="#my-container">
<div class="title">Companies</div>
<div class="tab active tab-apple">Apple</div>
<div class="tab tab-google">Google</div>
</div>
When page is loaded without any tab clicks yet, whichever tab with the default active class, needs to go in the .title div. For the example above, <div class="title">Apple</div>
On click of a tab, the class is switched to active, and vue.js needs to update the .title div once again.
How can this be done with vue.js? I've tried but not able to get it to work as intended.
The answer by David is one way to do it. But Vuejs offers in-line computations for this. So, no need to hook into any CSS event. Here's some code to explain:
Create a data property active_tab, just like David mentioned. And then bind it's value just like he's done it. In your tabs, add an click event and at that event, assign appropriate value to active_tab.
<div class="tab active tab-apple" #click="active_tab = Apple">Apple</div>
<div class="tab tab-google" #click="active_tab = Google">Google</div>
Now, to dynamically assign the active class to the respective tab, make the class attribute, a computed property, like this:
<div
:class="['tab', active_tab == 'Apple' ? 'active' : '', 'tab-apple']"
>
Apple
</div>
What this code is basically doing is, :class makes class a computed property. Then the commas in the array divide the statement. So, the computation will always add tab and tab-apple classes. But, only if active_tab == 'Apple' then ? add 'active' else : add ''
Not sure which CSS framework you are using, but normally I hook into the events thrown by the tab switching (many CSS frameworks provide this access). Once hooked into it, you can write a Vue custom directive that will take that event and use it to update a VM attribute that indicates which tab is active.
Then you can use normal mustache templating to get it into your template:
<div class="title">{{ active_tab }}</div>