I am having huge data, to display this I am using grid with paging enabled,
and loading the first page data.
How i can load the next page data in the back ground ??
so that when the user clicks next button I will show the data which is preloaded.
Any work around.
Thanks in advance,
kkchaitu
The simpliest solution could be a loading whole set of data to the store and use Paginating Toolbar for filtering purpose, however you refering that amount of data is "huge" - this could make solution uneffective...
or
Have 3 set of data ready (before - empty at start, actual, and after) and overwrite onload events:
after loading - display and load next, (or previous),
before load check is next (or previous) is avaible - use it, change what is prevoius, actual, next, prepare what should be loaded after (in background)
keep in mind that Ajax requests are asinchronic and clicking could be faster than loading and this should be predicted in logic... However this is just an idea
Related
I have a performance issue when I open ionic 3 Modal.
I need to show a list in the modal and the length of list is 1000.
It takes few seconds to open the modal while they are rendered.
I thought about using InfiniteScroll in the modal, But I use Searchbarwhich means server-side should develop more APIs for that.
Since the data of list is quite static, I would like to make like :
Preload the modal page and hide by default.
Show the modal when it should be opened.
When the modal is closed, DO NOT destroy it, just hide.
But according to the ionic docs, I can't reuse modal.
So my question is : Is there a better way to make searchable 1000 list in ionic3?
Thanks.
EDIT : I have tried with localStorage to save json (about 100kb) and stop using XHR to reduce loading time. However I don't feel loading time gotten faster. I tested with just 100 list instead of 1000 and opening modal was a lot faster.
There are a several options:
If it is actually static, just place it in web storage and retrieve it when the use reloads the page.
If it's "quite" static, whatever that means, just place it in the DOM somewhere so it only has to load once per page load. When the user clicks the link to open the modal, store the data in a hidden field. It might even be a good idea to load it asynchronously as the page is loading, which could potentially completely eliminate any loading times at all from the user's perspective.
Use your own modal, and just hide/show it. Load it async.
Example of cache
jQuery AJAX Example
Ok I made it by using <ion-infinite-scroll (ionInfinite)="doInfinite($event)">.
First of all, when modal is opened, get list data from the server
and save in local storage
In the beginning just show 20 items out of 1000. So the rendering
would be a lot faster.
When user scrolls down, doInfinite will be executed.
In the doInfinite function, check what is the next index in order to show
the data. Like pagination logic. And get proper data and push to
the list array.
About <ion-searchbar>, when you get list data from either server
or local storage, save an original list data for the search (In my case, I just used this.originalData = myData like that.). By doing so, whenever user searches by typing, you can filter from 1000 array but no slow rendering issue.
Set server paging true for Kendo Data source
Set Page Size 300 for Kendo Datasource
Set Virtual scroll true for kendo grid
Now make sure in grid has 6000+ records
Scroll down grid to middle (such that you want to see 300 record on 50th page)
If you observe in browser, kendo grid data source call to get records for each page still the 50th page arrived.
Yes it will call for every page if you don't move the scroller fast.
Kendo says following about virtualization : If set to true the grid will always display a single page of data. Scrolling would just change the data which is currently displayed.
There is an existing issue with multiple requests during fast scroll.
If you want to limit performance hit and you don't want to always load 300:
make page size smaller - in this case the virtualization is quite likely going to skip some pages. However this relies at the users skill to scroll fast, if they scroll slow all the pages will be loaded.
implement server side paging via pager and avoid virtualization- this will allow you to control what are you getting from the server.
I have a bit of a unique challenge today. I have a client that wants to be able to search for multiple items based on inserts into a cfgrid. Suppose we have the following web form:
A Country selection dropdown
A State Selection dependent AJAX dropdown
A city Selection dependent AJAX dropdown
An ADD Button
----------------------------------------------------
A CFGRID that will populate a row with selections when the user clicks the add button
----------------------------------------------------
And finally, a CLEAR button, and a GO button on the bottom.
The resulting page will then query the database and get some statistics about the cities selected. So, suppose an individual picks USA > Arizona > Scottsdale and USA > Arizona > Flagstaff. The grid below the options will 'save' each selection and reset to their default options, waiting for a user to pick additional options or click on 'GO'.
The resulting page will then generate columns that list some statistics about the communities and highlight the 'best of' between each selected community.
Each time a user selects the ADD button (assuming three criteria are selected) I want the information to be added into a CFGRID that displays the options selected. Then, After the user selects at least one country/city/state option, have all of the data in the CFGRID get passed to another page that does a query from the data selected. In theory, the user could pick as many communities as they want, assuming they are willing to let the database sludge through enough data to get what they want and wait through a 'loading' screen to get it.
I'm having these challenges, in no particular order:
- I have an HTML grid that I must use per client spec (No Java or Flash, must be HTML)
- I have no idea how to get the selected options into the CFGRID. I assume there is some JavaScript I can write that uses some sort of AddRow function to add data into the grid with the add button but cannot seem to find how to it on the interwebs
- After we conquer the above challenge, how do I pass the data from the grid into the results page? I thought about passing one big string or a structure, but I'm not sure how to do that through the URL or posting, nor how to get the data out of the grid. I wonder if I am better off coding some sort of string that gets passed from the options page to the results page with a get method instead of dealing with the stuff in the CFGRID and have the CFGRID serve only as a 'dummy' display container.
- Finally, after the pass is complete, I would need to loop through through the structure and perform a CFQUERY or CFSTOREDPROC on each row of data, then get the statistics I need to display on the results page. I assume this would depend on how I am getting the data from the options selection page to the results page.
THANK YOU ALL!
CFGRID is great to start, but it can be b*tch to customize and extend... Have you tried editable CFGRID with bind? See how far off it is from what you want first. If it turns out to be very far, then you might want to go for a jqGrid and code up some jQuery.
To start, read Using HTML grids and make the cfgrid editable.
http://help.adobe.com/en_US/ColdFusion/9.0/Developing/WSc3ff6d0ea77859461172e0811cbec22c24-7a01.html#WSc3ff6d0ea77859461172e0811cbec22c24-72e0
Once you got that working, look at these provided JS functions that you can use with CFGRID
http://help.adobe.com/en_US/ColdFusion/9.0/CFMLRef/WS0ef8c004658c1089-6262c847120f1a3b244-8000.html
http://help.adobe.com/en_US/ColdFusion/9.0/CFMLRef/WSd160b5fdf5100e8f-4439fdac128193edfd6-7f5f.html
If you still demand a bit more, you might need to dig into the underlying ExtJS component. At that point I would rather use jqGrid
I found out that the best way to handle this was by using a SerializeJSON call and a Deserialize JSON call back and forth. By using JavaScript notation we are able to pass a complex JavaScript object (array) between one page and another. This has the value add of not having to worry about sessions timing out and making URLs clickable from one solution to the next.
I have 2 dropdown in a view. First drop down is automatically populated when the view get's loaded with the list of options. when an item is selected I would like to populate the dropdown # 2.
What's the best way of doing this?
A couple ways of doing this. You can either do an AJAX call (responding to the selection of a value in dropdown #1). The downside to this is that it requires a round-trip call to the server, then updating the value of dropdown #2 with the result.
The other way is to pre-load all possible values for dropdown #2 when the page first loads, and just change it in the browser with JavaScript as soon as the value is changed (rather than making a call all the way back to the server to get the values).
Either way, you're modifying the DOM, most likely, so it'll be some kind of JavaScript solution. Whether you choose AJAX, or preload and change it immediately will probably depend on how it affects the original page load speed, how much data you want to load onto the client, etc. If it's a relatively small number of options possible in dropdown #2, then pre-loading might be your best bet.
I have a dropdown, that contains some list of StudentCode...
when user select any studentcode student data should be displayed in form with student's Image...
for displaying Student Image, Im putting student image in cache memory... and I have one Iframe that gets the byte data from cache memory and render that image on my page... problem is... this thing need at least 1 postback...
can I make some partial postback to render this image?
I see couple problems with the implementation.
1) You should avoid using IFrames in general as there are better ways of handling rendering parts of the webpage.
2) Storing images in cache means that you actually downloaded all of them for each Student in the dropdown list and placed them in the cache. What if there are 100 students? Getting images for all of them and storing them might take a lot of resources.
I suggest you to do the autopostback on dropdown selected value change (via ajax call) which calls a method that will return a partial view with all the information you need for the particular student, including the image.
I found using Ajaxify library (http://max.jsrhost.com/ajaxify/) very easy and convenient for ajax calls.
You can do the same thing without ajax at all in which case the whole page will reload with the same result.