Im working on a car sales website and using vue-router.
I have an index page with a list of all cars for sale, and then when clicked they link to the single view of that specific vehicle.
I have a large 'header' image on the single view page and have it inside a container with a fixed height so that when the page loads there is not jumping in page height.
When going to this single view, I do an API call to get the vehicle data and then wish to fade in the heading image.
To do this:
<div class="singleVehicle__mainImage">
<span :style="styles" :class="{'imageLoaded' : mainImageLoaded }" v-if="vehicle"></span>
</div>
export default {
data() {
return {
vehicle: null,
styles: {
backgroundImage: null
},
mainImageLoaded: null
}
},
created() {
this.getVehicle().then(() => {
this.mainImageBackground();
});
},
methods: {
mainImageBackground() {
var source = "IMAGE SOURCE URL";
this.styles.backgroundImage = "url("+source+")";
var $this = this;
var img = new Image();
img.onload = function() {
$this.mainImageLoaded = true;
}
img.src = source;
if (img.complete) img.onload();
}
}
}
By default, the span inside the image wrapper has a 0 opacity and then that is transitioned to 1 when the .imageLoaded class is added.
This works fine, but only the first time each vehicle loaded. The image waits till it loads and then fades in. Everyother time afterwards the image simply pops in when it loads almost like the imageLoaded class is not being reset / the data is not being reset when leaving the view.
When clearing browser cache, it works again but once for each vehicle view.
This is probably due to your v-if="vehicle". The vehicle call is possibly taking longer and so the span is not showing until after the class is added or some timing issue related to that.
Related
How do you maintain the previous scroll position after a post using asp.net core 3.1 MVC (web application) and razor views?
How do you do this across the site?
I saw this: ASP.NET MVC3 Razor - Maintain scroll position on postback - but those did not work for me.
First, Create a base view model that all other models will inherit
public class BaseViewModel
{
public int ScrollPosition { get; set; }
}
All view models that are bound that will need to remember the previous scroll position will inherit from this BaseViewModel
Second, Add a hidden input to your form used for posting:
#using(Html.BeginForm("SomeAction", "SomeController", FormMethod.Post)
{
#Html.HiddenFor(x => Model.ScrollPosition)
....
}
Third, inside your post method on the backend set a value to TempData:
TempData["ScrollPosition"] = Model.ScrollPosition;
Fourth, when redirect after post, set this value to your Model for binding in your view:
MyModel.ScrollPosition = (int)TempData["ScrollPosition"];
Fifth, use javascript to scroll to previous position after page load:
<script type="text/javascript">
window.addEventListener("DOMContentLoaded", function(){
//add event listener for the scroll event and set hidden input value for posts
document.addEventListener('scroll', function(){
const scrollPosY = window.scrollY;
document.querySelector('input[name="ScrollPosition"]').value = scrollPosY;
});
const scrollpos = document.querySelector('input[name="ScrollPosition"]').value;
window.scrollTo(0, scrollpos); //y-axis scroll
});
</script>
If you would need to track x axis scroll as well as y axis, you'd need two hidden inputs
for each x and y axis scroll position and change model to hold both x and y
Another way to do this is to submit the form with AJAX and, after a successful POST, call window.location.reload(); which will restore the scroll position.
function CreateItem() {
var serializedForm = $('#formId').serialize();
$.ajax({
url: "item/create",
type: "POST",
data: serializedForm
})
.done(function () {
window.location.reload();
});
}
First add the following jquery function to your page in the script tag:
$(document).scroll(function () {
// Note scroll position.
localStorage['pageIdentifier'] = $(document).scrollTop();
});
And then add:
$(document).ready(function () {
// Maintain scroll position.
$(document).scrollTop(localStorage['healthPage']);
});
My component is a modal which displays an <img> with some tags on top.
I get the image dimensions using const size = this.$refs.media.getBoundingClientRect().
However, the height and width is 0, so the tags become placed wrong.
So it seems the image hasn't loaded yet? If I delay getting the height+width with setTimeout, I do get the width and height. But it seems like a not too reliable workaround.
I have "v-cloak" on the modal, but that doesn't work.
I can get the html element with this.$refs.media, but it doesn't mean that the image is loaded, apparently.
So, is there a way to check if the image is loaded? Is there some way to delay the component until the image is loaded?
One more thing: if I add a "width" and "height" in inline style on the img, then those values are available directly. But I don't want to set the size that way because it ruins the responsiveness.
The code doesn't say much more, but it is basically:
<modal>
<vue-draggable-resizable // <-- each tag
v-for="( tag, index ) in tags"
:x="convertX(tag.position.x)"
:y="convertY(tag.position.y)"
(other parameters)
convertX (x) {
const size = this.$refs.media.getBoundingClientRect()
return x * (size.width - 100) // <--- 0 width
async mounted () {
this.renderTags(this.media.tags) // <-- needs img width and height
Updated, solution
As the below answer says, I can use the onload event. I also came across the "#load" event, which I tried and it worked. I can't find it in the documentation though(?) (I searched for #load and v-on:load). Using "onload" directly on the image element didn't work though, so #load seems to be the way.
If I have a data property:
data () {
return {
imgLoaded: false
I can set it to true with a method using #load on the image:
<img
#load="whenImgLoaded"
<template v-if="imgLoaded = true">
<vue-draggable-resizable
:x="convertX(tag.position.x)"
:y="convertY(tag.position.y)"
(other parameters)
methods: {
whenImgLoaded(){
this.imgLoaded = true;
this.renderTags(this.media.tags)
}
You could load the image first via javascript, and after it's loaded run the renderTags method.
E.g., do something like this:
async mounted() {
let image = new Image();
image.onload = function () {
this.renderTags(this.media.tags)
};
image.src = 'https://some-image.png'
}
i am working in extjs4. i have form panel with autoscroll true. I have 20-25 fields with fileUpload field at bottom. When i am uploading file, form's scroll is going to top by default. i want to keep scroll of form as it is on where it was while uploading file. So how to set this scrollBar at bottom of or at upload field section in extjs4
You can try by adding the following method to your form declaration:
scrollToField: function(fieldId) {
var field = Ext.get(fieldId);
field.el.scrollIntoView(this.body.el);
}
Here you have a working sample
IMHO,it will be better, however, to group fields using tabs or something similar to avoid having a long a and hard to read / fill form
I have solve this problem into Ext js 4.2 for Ext.form.panel
See the following code. It will helpful to you.
onRender function call on render event
onRender: function () {
this.callParent(arguments);
if (!this.restoreScrollAfterLayout) {
this.mon(Ext.get(this.getEl().dom.lastElementChild), 'scroll', this.onScroll, this);
this.restoreScrollAfterLayout = true;
}
},
onScroll: function (e ,t, eOpts) {
this.scroll = Ext.get(this.getEl().dom.lastElementChild).getScroll();
},
afterLayout: function () {
this.callParent(arguments);
if (this.restoreScrollAfterLayout && this.scroll) {
var el = Ext.get(this.getEl().dom.lastElementChild),
scroll = this.scroll;
el.scrollTo('left', scroll.left);
el.scrollTo('top', scroll.top);
}
}
I have a WinJS application with listviews in which if quickly navigate between pages before the listview is fully loaded, the next page shows the listview with all elements in it bound as "undefined".
So say I have a hub page with a "to do" that is filtered to only show 6 items, and there is a header that navigates to the full "to do" page, when the hub page is displayed but before it is fully loaded I click on the header link to the "to do" page, the app then goes to the "to do" page, but the items show up with all the properties in the tile as "undefined".
I am using IndexedDB as my data store.
My home page code looks like this:
WinJS.UI.Pages.define("/pages/home/home.html", {
ready: function (element, options) {
WinJS.Utilities.query("a").listen("click", function (e) {
e.preventDefault();
WinJS.Navigation.navigate(e.currentTarget.href);
}, false);
viewModel = new HomeViewModel(element);
viewModel.load(); //loads from indexed db
},
//etc...
To Do Page:
WinJS.UI.Pages.define("/pages/ToDo/ToDo.html", {
ready: function (element, options) {
viewModel = new ToDoViewModel(element);
viewModel.load();
},
etc//
I know there isn't much to go off, but any ideas would be appreciated.
Also tips on how to debug something like this would be great.
Update
I narrowed it down to this one line from the Hub Page:
myLib.GetData(todaysDate, function (result) {
that.trendsModel.today = result;
WinJS.Binding.processAll(that.el.querySelector("#dataPanel"), that.trendsModel); //<--Right Here
});
If I remove that, then when I load the second page the data doesn't show as undefined. What is interesting is the data initially shows correctly on the second page and then it changes to "undefined".
Solution
My fix:
myLib.GetData(todaysDate, function (result) {
var element = that.el.querySelector("#dataPanel");
that.trendsModel.today = result;
if(element) {
WinJS.Binding.processAll(element, that.trendsModel);
}
});
At the point when when the callback returns, I am already on the second page. So the selector was not found returning null. If you pass null to processAll it tries to bind the whole page which is why I was able to see the correct data for a second then it changes to undefined...Wow, what a doozy. I guess it makes sense but what a pain to find.
Hope it helps someone in the future :)
Your ToDoViewModel, and HomeViewModel need to be observable. This means they need to mix in from WinJS.Binding.mixin, and for the properties that you pull in asynchronously, they need to call this.notify("propertyName", newVal, oldVal) from the property setter.
Note that you need to have getter/setter properties. e.g.
var bindingBase = WinJS.Class.mix(function() {}, WinJS.Binding.mixin);
WinJS.Namespace.define("YourNamespace", {
ToDoViewModel: WinJS.Class.derive(bindingBase, function constructor() {
}, {
_titleStorage: "",
title: {
get: function() { return this._titleStorage; },
set: function(newValue) {
if(newValue === this._titleStorage) {
return;
}
var old = this._titleStorage;
this._titleStorage = newValue;
this.notify("title", newValue, old);
}
}
}),
});
myLib.GetData(todaysDate, function (result) {
var element = that.el.querySelector("#dataPanel");
that.trendsModel.today = result;
if(element) {
WinJS.Binding.processAll(element, that.trendsModel);
}
});
At the point when when the callback returns, I am already on the second page. So the selector was not found returning null. If you pass null to processAll it tries to bind the whole page which is why I was able to see the correct data for a second then it change to undefined...Wow, what doozy. I guess it makes sense but what a pain to find.
How do you make a titlePane's height dynamic so that if content is added to the pane after the page has loaded the TitlePane will expand?
It looks like the rich content editor being an iframe that is loaded asynchronously confuses the initial layout.
As #missingno mentioned, the resize function is what you want to look at.
If you execute the following function on your page, you can see that it does correctly resize everything:
//iterate through all widgets
dijit.registry.forEach(function(widget){
//if widget has a resize function, call it
if(widget.resize){
widget.resize()
}
});
The above function iterates through all widgets and resizes all of them. This is probably unneccessary. I think you would only need to call it on each of your layout-related widgets, after the dijit.Editor is initialized.
The easiest way to do this on the actual page would probably to add it to your addOnLoad function. For exampe:
dojo.addOnLoad(function() {
dijit.byId("ContentLetterTemplate").set("href","index2.html");
//perform resize on widgets after they are created and parsed.
dijit.registry.forEach(function(widget){
//if widget has a resize function, call it
if(widget.resize){
widget.resize()
}
});
});
EDIT: Another possible fix to the problem is setting the doLayout property on your Content Panes to false. By default all ContentPane's (including subclasses such as TitlePane and dojox.layout.ContentPane) have this property set to true. This means that the size of the ContentPane is predetermined and static. By setting the doLayout property to false, the size of the ContentPanes will grow organically as the content becomes larger or smaller.
Layout widgets have a .resize() method that you can call to trigger a recalculation. Most of the time you don't need to call it yourself (as shown in the examples in the comments) but in some situations you have no choice.
I've made an example how to load data after the pane is open and build content of pane.
What bothers me is after creating grid, I have to first put it into DOM, and after that into title pane, otherwise title pane won't get proper height. There should be cleaner way to do this.
Check it out: http://jsfiddle.net/keemor/T46tt/2/
dojo.require("dijit.TitlePane");
dojo.require("dojo.store.Memory");
dojo.require("dojo.data.ObjectStore");
dojo.require("dojox.grid.DataGrid");
dojo.ready(function() {
var pane = new dijit.TitlePane({
title: 'Dynamic title pane',
open: false,
toggle: function() {
var self = this;
self.inherited('toggle', arguments);
self._setContent(self.onDownloadStart(), true);
if (!self.open) {
return;
}
var xhr = dojo.xhrGet({
url: '/echo/json/',
load: function(r) {
var someData = [{
id: 1,
name: "One"},
{
id: 2,
name: "Two"}];
var store = dojo.data.ObjectStore({
objectStore: new dojo.store.Memory({
data: someData
})
});
var grid = new dojox.grid.DataGrid({
store: store,
structure: [{
name: "Name",
field: "name",
width: "200px"}],
autoHeight: true
});
//After inserting grid anywhere on page it gets height
//Without this line title pane doesn't resize after inserting grid
dojo.place(grid.domNode, dojo.body());
grid.startup();
self.set('content', grid.domNode);
}
});
}
});
dojo.place(pane.domNode, dojo.body());
pane.toggle();
});
My solution is to move innerWidget.startup() into the after advice to "toggle".
titlePane.aspect = aspect.after(titlePane, 'toggle', function () {
if (titlePane.open) {
titlePane.grid.startup();
titlePane.aspect.remove();
}
});
See the dojo/aspect reference documentation for more information.