Loading kendo grid is very slow.
I have a grid with 500-1000 records and 40 different columns.
The grid loads slowly. It takes few seconds(10-15) to load the grid.
Let's say the datasource is observable and is specified like this.
kendoDataSource = new kendo.data.Datasource({
data: observableArray
})
what is the best way to update the records and show them on the UI.
Should I use?
observableArray.push.apply(observableArray, newData)
or
grid.kendoDataSource.data(observableArray)
or
define a newDataSource with newData and set it again
kendo.setDataSource(newDataSource)
Finally, how do I know whether the Grid is loaded completely? I have a busy indicator which spins up in the center of the grid and I want to hide the busy indicator after the grid is loaded.
What I do currently is
observableArray.push.apply(observableArray, newData)
//hide the busy indicator.
Since the grid is still loading in the background, after I hide the busy indicator, the grid is blank for a while or shows the previous data for a while.
The user thinks that the grid is loaded with empty screen. Few seconds later, all the records appear in the screen.
The best approach is the data method if only the data is changed. This will replace the entire data at once causing only one re-render.
The indicator can be hidden in the dataBound event as this indicates that the Grid is rendered.
Related
I'm looking to apply infinite scrolling to an ag-grid table with a large amount of data on page where 50 new rows will be added at a time based on the BROWSER height and/or scrollbar being scrolled down, instead of the TABLE size and/or scroll bar being scrolled down.
I tried domLayout='autoHeight' but that seems to only affect the table. Note: I will be using a large amount of data in this table and I'd like to do this using ag-grid properties and events, etc if it's possible to do it with solely ag-grid.
I’d like it to function like this example:
http://intercoolerjs.org/examples/infinitescroll.html
See how the table loads more data as the user scrolls with the BROWSER scrollbar?
I need and answer by 4PM Mountain Time if possible.
Thanks in advance for any help!
Dave
I have a SD grid to show messages received from other users (a simple chat app) and every time I open this panel, the first records appears and I have to manually scroll to reach last message.
Is there a way to automatically go to last record on this grid ?
I know there is a Select() method on grids, but this can´t be used on Refresh Event, only on user events.
I´m using GX15 U6
Thanks,
Rogelio Arosemena
Yes, it is possible with Inverse Loading property
This property is available for grids in the Smart Devices generator.
By setting it to True (its default value is False), the developer will
be able to load the grid in reverse direction (i.e. the Common Grid
will be loaded from bottom to top, and the Horizontal Grid will be
loaded from right to left).
Example of use The canonical use case of inverse loading on a grid is
that of a chat messaging system. What are its characteristics? It is
loaded from bottom to top, pagination is performed with a swipe-down
gesture, and when the user refreshes it the first page will be
displayed in the lower section.
I have one WWSD or one SDPanel with some attributes but between these attributes that are fixed inside a Table or directly in the MainTable I want put and Grid, the problem is that the Grid is not showed and when I put the grid its no more possible scroll in the WWSD or SDPanel, is like the Grid stuck the SDPanel more than the grid is not showed.
Anyone can help me to put the Grid and keep with all normally ?
Thx.
I assume you're targeting Android.
The issue is that Android does not natively support nested scrolling. Therefore, a GeneXus layout that contains a grid will disable the form's own scrolling (so that the grid can itself scroll).
There are two ways of resolving this issue:
Redesign the panel so that the form does not vertically exceed the size of the screen (thus, form scrolling is not necessary).
Set autogrow=true for the grid, which will resize to fit all items (and "push down" any other controls located below it). Since the grid will no longer need to scroll, the form's scroll will be enabled.
We're using lots and lots of Kendo grids, many of which have virtual scrolling set up with a server-side data source.
Sometimes, one of them will hide records beyond the "reach" of the virtual scrollbar. We can see what's going on by using Developer Tools to make the internal scrollbar visible:
It's hard to put a finger on when this happens exactly - the bug keeps popping up in seemingly random places.
Any ideas how to narrow this down / deal with it?
Try resetting the virtual scroller in the grid onDataBound event.
onDataBound: function(evt) {
//Repaint the virtual scroll bar to make sure all rows are visible to user
var grid = evt.sender.wrapper.data("kendoGrid");
grid._rowHeight = undefined;
grid.virtualScrollable.refresh();
},
You need to do this on detail row expand and shrinks as well.
I tried virtualScrollable.refresh(), does not fully shown the hidden content, but using resize(true) works
$("#yourGridId").data("kendoGrid").virtualScrollable.refresh(); //does not fully show hidden content
$("#yourGridId").data("kendoGrid").resize(true); //works
just need to call this from all the related events (still working on identifying them)
As Telerik (more or less) points out in the docs, changes to the rowheight in a grid with virtual scrolling won't work when the grid has display: none.
We had an event handler that would hide the grid and fire an async call. On success of the async call, we were changing a value that resulted in a different rowheight (removed bold from one row).
That was enough to throw off the scrolling as pictured.
I am building a page which contains many charts, which are displayed one at a time depending on which tab you are looking at.
The chart in the initially active tab renders correctly. However when I click to another tab, the chart is not rendered properly.
Presumably this is because the hidden field does not have dimensions until it is made visible. In fact if I resize the window the chart will correct it's proportions, and render so that it fills the available width.
I can fix this problem by explicitly defining the chart size via css, but this defeats the responsive aspect of the charts.
Can anyone tell me how to trigger the same NVD3 event which gets activated when the window resizes? That way I can bind it to the selection of a new tab, and hopefully remedy the rendering issue.
I had the same issue (charts on multiple tabs), and this is the only thing that I could get to work.
$(function () {
$(document).on('shown.bs.tab', 'a[data-toggle="tab"]', function (e) {
window.dispatchEvent(new Event('resize'));
});
});
I have a feeling, however, that all of the charts are being re-rendered, regardless of whether they are on the active tab (visible) or in the non-selected tabs (hidden).
Does anyone know how to ensure ONLY the active chart gets resized / redrawn?
I figured out how to trigger the resize event I needed. In my case the tabs are driven by bootstrap. So I simply modified my bootstrap show tab event to trigger a page resize event as well. It's a little indirect, but it gets the job done:
jQuery('#myTab a').click(function (e) {
e.preventDefault()
jQuery(this).tab('show')
jQuery(window).trigger('resize'); // Added this line to force NVD3 to redraw the chart
})
Just add this JavaScript:
$('a[data-toggle="tab"]').on('shown.bs.tab', function (e) {
window.dispatchEvent(new Event('resize'));
})
hidden.bs.tab is the event that fires after a new tab is shown as per the Bootstrap docs. This code fires a resize event after each tab change.
Reason For New Answer
Vanilla Javascript is necessary for a lot of people in 2018. As a lot of frameworks and Javascript libraries that exist today do not play well with jQuery. Once upon a time answering all Javascript problems with a jQuery solution was acceptable but it is no longer feasible.
Problem
When loading C3.js or D3.js graphs, if the viewport is not actively in site during page load the graphs do not render correctly.
Example
If you type in the URL then open a new tab and then go back after your page loads.
If you refresh the page that has your graphs on it then minimize the browser and open it back up after the page has loaded.
If you refresh or go to the page with the graphs then swipe away to a new window on your computer. Then go back to the page with the graphs after they have loaded.
In all these cases your C3.js / D3.js graphs will not render correctly. Typically you will see a blank canvas. So if you were expecting a bar chart, you would see a canvas without the bars being drawn.
Background
Although I have seen this question answered I needed an answer that did NOT use jQuery. Now that we have reached the days of everything can not be fixed with jQuery I thought it seemed fit to provide a vanilla Javascript answer to this question.
My team faced the issue that the C3.js / D3.js graphs would not load if you refreshed the page and swiped away or minimized. Basically if you did not stay on the page and keep it in site till it was done loading you would not see the graphs till you resized the page again. I know this is a problem that happens to everyone using C3.js / D3.js but we are specifically using Lightning in Salesforce.
Answer
Our fix was to add this in the controller function that initializes the charts. Anyone can use this in any function they write to initialize their C3.js / D3.js graphs regardless of their stack. This is not Salesforce dependent but it does indeed work if you are facing this issue in Salesforce.
document.addEventListener('visibilitychange', () => {
console.log(document.visibilityState);
window.dispatchEvent(new Event('resize'));
});
I was facing same issue. I was using ng-show to make div hidden . Once I replaced ng-show with ng-if I am able to see graph drawn in expected behavior. Explanation:
When we use ng-show or ng-hide to make div hidden it only changes it display property but div will be in dom.
When we use ng-if div is removed from dom and again added to dom so internally it performs redraw operation on nvd3 graph too. Hence we see correct graph instead of squished one.
The event that usually triggers a redraw is the window resize event -- NVD3 doesn't use a custom event for this. You can control this yourself though; the usual definition is
nv.utils.windowResize(function() { d3.select('#chart svg').call(chart); });
(where "#chart" is the element that contains the graph). There's nothing stopping you triggering the code on another event or even just running the redraw code explicitly when you change the tab.
a more efficient approach would be to use the chart.update() method
var chart_x = nv.models.somechart()
var chart_y = nv.models.somechart()
..... show charts
jQuery('#myTab a').click(function (e) {
e.preventDefault()
jQuery(this).tab('show')
if(jQuery(this)...something === '..x..')
chart_x.update(); //CALL THE UPDATE
else ...
})