How do I avoid expanding sections when using a composed view? - durandal

At various places in my single page app I use composition to compose one view into another. At the same time I have noticed some animation effects when certain pages load, almost as if sections were dynamically expanding as binding, etc. took place. I am pretty sure that this has nothing to do with Durandal's transitions as I disabled that and still got the expanding "animation" effect.
This morning I created a new view, copied some existing HTML from another view into it and replaced this HTML in the parent view with the new composed child view. In other words, the parent view went from this:
<div data-bind="visible: contactPerson, with: contactPerson">
<span data-bind="text: firstName"></span><br />
<span data-bind="text: lastName"></span><br />
</div>
to this:
<div data-bind="compose: { model: 'viewmodels/contact-view', activationData: { contactPerson: contactPerson } }"></div>
Upon testing this change I immediately noticed that the original version had no expanding animation effect while the composed version does. After playing around with the Durandal transitions I came to the conclusion that this is quite possibly not related to that but more probably due to delayed insertion of the child view HTML.
The new child viewmodel is extremely simple so I see no issues there, unless it has to do with the fact that it is not a singleton, which it cannot be in this case.
define(['services/dataservice',
'services/logger'],
function (dataservice, logger) {
return function () {
var self = this;
var contactPerson = ko.observable();
var activate = function (activationData) {
contactPerson(ko.unwrap(activationData.contactPerson));
};
// Make sure required internally defined functions and properties are exported.
self.activate = activate;
self.contactPerson = contactPerson;
};
});
Can anybody help me figure out how to get rid of the transition effect? I can post a video of the before and after if somebody wants to take a look at it.

Composition does not, in itself, cause the effect you are witnessing. It is most likely a CSS issue. We witnessed the same effect many times (particularly when trying to position a wait spinner) and it was always the CSS.
In those cases where we want to "make room" for an incoming view, we set our CSS on the container that will hold the view in such a way as to have that container "expanded" already, so to speak. Think "placeholder," if you will.

If you are in debug mode with caching disabled then the composition binding is much slower than in a built app. You see this effect because of the debug mode and how it is writing and evaluating each binding to the console as well. If you want to disable it turn off debug mode or look at the built version of your application.

Related

Nuxt-link delay transition to new page?

This is a follow up to #1458. I'm looking for some direction on how Nuxt expects this to be handled.
I have a menu. When I click on a nuxt-link in the menu, I want to have time to close the menu before the page transition happens. The thing is, I only want that to happen when you click on the nuxt-link in the menu, not every time I go to a certain route (as the previous issue described using a middlewear on the route).
So there are a few different ways to do this, and I'm curious what the "Nuxt" way is?
The way we currently do this, disable the nuxt-link and capture the click, then do a router.push().
<nuxt-link :to="path" event="disabled" #click.native="delayLoad"/>
// Methods
delayLoad(event) {
this.$store.commit("CLOSE_MENU")
setTimeout(()=>{
this.$router.push(event.target.pathname)
}, 2000)
}
Is this a good idea? I just always have an aversion to hijacking nuxt-link and browser navigation like this. It seems janky.
The other ideas we played with were using a query param on the nuxt-link, and then using that in a middlewear to delay the page transition. That seemed worse to me, because now my URL's have a query param in them that is used for an animation, seems like that is abusing query params. This also triggers the page loading progress bar, which isn't really the intent, it's to have a sequenced animation happen, then page load.
It seems to me that perhaps nuxt-link should have a delay prop, or perhaps the page transition config should allow for a delay (like it does with duration)?
I wanted to do this as well and came up with the following solution. Using the new slots api you can more elegantly customise the nuxt-link behaviour:
<nuxt-link v-slot="{ route, href }" :to="path" custom>
<a :href="href" #click.prevent="$emit('navigate', route)">
<slot></slot>
</a>
</nuxt-link>
This will make the link emit a navigate event with the route as a param. You then listen for this event wherever you include your menu component, like this:
<template>
<transition
name="fade"
#after-leave="maybeNavigate"
>
<MainMenu
v-if="menuIsVisible"
#navigate="navigate"
/>
</transition>
</template>
<script>
export default {
data: () => ({
menuIsVisible: false,
navigateToOnMainMenuClose: null,
}),
methods: {
navigate(route) {
this.navigateToOnMainMenuClose = route
this.menuIsVisible = false
},
maybeNavigate() {
if (this.navigateToOnMainMenuClose) {
this.$router.push(this.navigateToOnMainMenuClose)
this.navigateToOnMainMenuClose = null
}
},
},
}
</script>
Whenever you click a nav link in the menu, the route will be stored and the menu will close. After the menu out animation has finished, maybeNavigate() will push the stored route, if there is one. This removes the need for a setTimeout and if you manage to click multiple links in quick succession only the last one will be stored and navigated to.
Since nuxt-link is essentially a wrapped version of vue's router-link, if you look at the documentation for that there is an event property that accepts string or string[], looking at it's source code here: https://github.com/vuejs/vue-router/blob/dev/src/components/link.js#L86
you can see it will register a listener for disabled in this instance. It may make more sense to pass an empty array so that no event listeners are registered, but that's at the cost of readability.
Otherwise, #click.native is the suggested way to handle custom click handlers for router-link (see: https://github.com/vuejs/vue-router/issues/800#issuecomment-254623582).
The only other concerns I can think of are what happens if you click 2 different links in rapid succession and what happens if you click more than once. May just want to add a variable to track if a link has been clicked to prevent firing setTimeout multiple times, which could navigate you from page A to B and then to C as all timeouts will fire if not canceled. Or maybe you want to only navigate to the 'last' link clicked, so if another link is clicked, you would cancel the earlier setTimeout. This is realistically an edge case that probably won't be an issue, but worth exploring.
Otherwise, IMO, looks good to me. This seems like the simplest way to implement this without having to create a custom component / plugin. I'm no expert, but is likely how I would implement this functionality as well. It would be nice to see a delay option though since I can see myself using that functionality as well with vuetify.
Another potential method would be to do your store commit in beforeTransition: https://nuxtjs.org/api/configuration-transition/
Though I'm not sure that there is access to the store there, so you might have to write a custom plugin for that as well. Again, seems more complicated than it's worth for a simple delayed animation. Simple, working code is sometimes the best solution, even if it's not the most extensible option.
See also: How can I transition between two nuxt pages, while first waiting on a child component transition/animation to finish?
for another way of handling this.

Can Vue-Router handle clicks from normal anchors rather than router-link?

I have a scenario where there are two major components on a page; a frame-like component that contains common functionality for many applications (including a bookmark/tab bar) and my actual application code.
Since the frame doesn't actually own the page that it's included on, it seems like it would be incorrect for it to define any routes, however the current page may define their own routes that may match one of those links. In that case, I'd like vue-router to handle those anchor clicks and navigate appropriately rather than doing a full page reload.
Here's a simplified template of what this looks like:
Frame (an external dependency for my app):
<Frame>
<TabStrip>
</TabStrip>
<slot></slot>
<Frame>
App1:
<Frame>
<App>You're looking at: {{ pageId }}!</App>
</Frame>
So when any of the app1 domain links are clicked from that tab strip, I want my route definitions in app1 to pick that up rather than it causing a page load. Since that component is owned by the frame, I don't have access to write <router-link> since links to many different apps may co-exist there.
Any thoughts?
Whoo, this is an old one! However, since this question was high in my search results when I was researching this problem, I figured I should answer it.
My use-case was similar to the one in the comments: I needed to capture normal <a> links within rendered v-html and parse them through the router (the app is rendering Markdown with a light modification that generates internal links in some cases).
Things to note about my solution:
I'm using Vue3, not Vue2; the biggest difference is that this is the new Vue3 composition-style single page component syntax, but it should be easy to backport to Vue2, if necessary, because the actual things it's doing are standard Vue.
I stripped out the markdown logic, because it doesn't have anything to do with this question.
Note the code comment! You will very likely need to design your own conditional logic for how to identify links that need to be routed vs. other links (e.g. if the application in the original question has same-origin links that aren't handled by the Vue app, then copy/pasting my solution as-is won't work).
<script setup>
import { useRouter } from "vue-router"
const router = useRouter()
const props = defineProps({
source: {
type: String,
required: true,
},
})
function handleRouteLink(event) {
const target = event.target
// IMPORTANT! This is where you need to make a decision that's appropriate
// for your application. In my case, all links using the same origin are
// guaranteed to be internal, so I simply use duck-typing for the
// properties I need and compare the origins. Logic is inverted because I
// prefer to exit early rather than nest all logic in a conditional (pure
// style choice; works fine either way, and a non-inverted conditional is
// arguably easier to read).
if (!target.pathname || !target.origin || target.origin != window.location.origin) {
return
}
// We've determined this is a link that should be routed, so cancel
// the event and push it onto the router!
event.preventDefault()
event.stopPropagation()
router.push(target.pathname)
}
</script>
<template>
<div v-html="source" #click="handleRouteLink"></div>
</template>

Win8 JS App: How can one prevent backward navigation? Can't set WinJS.Navigation.canGoBack

Fairly new to developing for Windows 8, I'm working on an app that has a rather flat model. I have looked and looked, but can't seem to find a clear answer on how to set a WinJS page to prevent backward navigation. I have tried digging into the API, but it doesn't say anything on the matter.
The code I'm attempting to use is
WinJS.Navigation.canGoBack = false;
No luck, it keeps complaining about the property being read only, however, there are no setter methods to change it.
Thanks ahead of time,
~Sean
canGoBack does only have a getter (defined in base.js), and it reflects the absence or presence of the backstack; namely nav.history.backstack.
The appearance of the button itself is controlled by the disabled attribute on the associated button DOM object, which in turn is part of a CSS selector controlling visibility. So if you do tinker with the display of the Back button yourself be aware that the navigation plumbing is doing the same.
Setting the backstack explicitly is possible; there's a sample the Navigation and Navigation History Sample that includes restoring a history as well as preventing navigation using beforenavigate, with the following code:
// in ready
WinJS.Navigation.addEventListener("beforenavigate", this.beforenavigate);
//
beforenavigate: function (eventObject) {
// This function gives you a chance to veto navigation. This demonstrates that capability
if (this.shouldPreventNavigation) {
WinJS.log && WinJS.log("Navigation to " + eventObject.detail.location + " was prevented", "sample", "status");
eventObject.preventDefault();
}
},
You can't change canGoBack, but you can disable the button to hide it and free the history stack.
// disabling and hiding backbutton
document.querySelector(".win-backbutton").disabled = true;
// freeing navigation stack
WinJS.Navigation.history.backStack = [];
This will prevent going backward and still allow going forward.
So lots of searching and attempting different methods of disabling the Back Button, finally found a decent solution. It has been adapted from another stackoverflow question.
Original algorithm: How to Get Element By Class in JavaScript?
MY SOLUTION
At the beginning of a fragment page, right as the page definition starts declaring the ready: function, I used an adapted version of the above algorithm and used the resulting element selection to set the disabled attribute.
// Retrieve Generated Back Button
var elems = document.getElementsByTagName('*'), i;
for (i in elems)
{
if((" "+elems[i].className+" ").indexOf("win-backbutton") > -1)
{
var d = elems[i];
}
}
// Disable the back button
d.setAttribute("disabled", "disabled");
The code gets all elements from the page's DOM and filters it for the generated back button. When the proper element is found, it is assigned to a variable and from there we can set the disabled property.
I couldn't find a lot of documentation on working around the default navigation in a WinJS Navigation app, so here are some methods that failed (for reference purposes):
Getting the element by class and setting | May have failed from doing it wrong, as I have little experience with HTML and javascript.
Using the above method, but setting the attribute within the for loop breaks the app and causes it to freeze for unknown reasons.
Setting the attribute in the default.js before the navigation is finished. | The javascript calls would fail to recognize either methods called or DOM elements, presumably due to initialization state of the page.
There were a few others, but I think there must be a better way to go about retrieving the element after a page loads. If anyone can enlighten me, I would be most grateful.
~Sean R.

Existing widgets not available in a widget template in some (strange) cases

This took me a while. A long while. I battled two problems at once (circular dependencies, fixed with refactoring, and this problem). To get this problem into a JSFiddle required a LOT of work... but I think it was worth it.
So:
http://jsfiddle.net/EVbTL/3/
I define three widgets:
r.AppMainScreen -- This is the main app's widget. Easy: just a bunch of tabs, and a button which contains a simple button, which goes:
// SUbmit form
this.form.onSubmit = function(e){
e.preventDefault();
console.log("HERE");
dialog = new r.RetypePasswordDialog();
dialog.show();
return false;
}
Pretty uninteresting.
r.RetypePasswordDialog() -- A templated widget which represents a dialog box. The only interesting thing about it is:
< input name="password" id="${id}_password" data-dojo-attach-point="password" data-dojo-type="app.ValidationPassword" />
It's a simple custom widget, defined in this very file, which does validation. NOTE: I know there is no point in having a subclass here for this little work. Please keep in mind that this is an example.
r.ValidationPassword()
An augmented ValidationTextBox with some extra validation.
If you click on the button, you get:
Uncaught Error: Could not load class 'app.ValidationPassword
...?!? app.ValidationPassword has definitely been defined. It ought to be available there. At the beginning, I thought it was because of aa circular dependency (it was very fun, yesterday: I had to learn about AMD circular dependencies WHILE trying to figure out this problem...)
If you uncomment this line, executed within the script:
TEST = new r.RetypePasswordDialog();
The whole thing works. It's a meaningless instance, and I cannot figure out why on earth this would or should make a difference.
Explanations most welcome... I couldn't find any!
Thank you,
Merc.
app = new r.AppMainScreen( {});
You redefine the global app variable here, but are trying to use it elsewhere as the base object for your type system. Use var to scope variables to the function.

Dojo and unregistering widgets

I am new to the Dojo Toolkit. I'm getting the error
Tried to register widget with id=myButton but that id is already registered
whenever I try to load dojo content twice (meaning I load HTML content through jQuery.Load into a container div). Is there a way of unregistering already registered widgets in dojo? I've seen some examples, but I don't really get them working.
My button:
<button dojoType="dijit.form.Button" id="myButton">button</button>
If you're looking to unregister specific widgets, you can use their destroy() or destroyRecursive() methods. The second one destroys any widgets inside the one you are destroying (i.e. calling destroyRecursive on a form widget will also destroy all the form components).
In your case, it sounds like your best bet would be to do this before jQuery.load -
var widgets = dijit.findWidgets(<containerDiv>);
dojo.forEach(widgets, function(w) {
w.destroyRecursive(true);
});
The above code will unregister all widgets in <containerDiv>, and preserve their associated DOM Nodes. To destroy the DOM nodes, pass false to destroyRecursive instead.
Reference:
http://dojotoolkit.org/api/1.3/dijit/_Widget/destroyRecursive
Based on http://bugs.dojotoolkit.org/ticket/5438, I found a sufficient way of destroying dojo-widgets:
dijit.registry.forEach(function(w){
w.destroy();
});
This worked for me:
dijit.byId( 'myButton' ).destroy( true );
I think you would be better off removing the id from your button and accessing it using an attach point. You would basically do <button dojoType="dijit.form.Button" data-dojo-attach-point="myButton">button</button>
then in your code you would access it like this.myButton.... however im not sure which version of dojo you are using. This will fix any id issues since dojo will assign a unique id to it automatically.