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While loading PDFView by Dynamic component loader data moving/refreshing speed goes very slow than usual

While loading PDFView by Dynamic component loader, if I view data by mousewheel, data moving/refreshing speed goes very slow than usual, which also affect all other pages.

It happens when I operate by the following steps:

1. Open PDFView at GridList




2. Use mousewheel function on PDFView page, then the data moving/refreshing speed slows down. However, it works well if using the Left/Right Click of mouse.


3. Close the PDFView page and go back, the data moving/refreshing speed by mousewheel slows down, too.



Attachment: pdfview_8ec80d24.zip

15 Replies
DM Dhivyabharathi Mohan Syncfusion Team October 19, 2021 12:52 PM UTC

Hi Techlandandyzh, 
 
 
Syncfusion PDF Viewer control is client-server oriented. PDF viewer control processes the PDF document on the server-side (developed with the .NET environment) and sends the processed PDF data to the client (Angular) using the web service to render the PDF document and for further operations in PDF viewer. Also, we are rendering the pages on-demand, so on scrolling, we will send the request to the server to get the page details for displaying in PDF Viewer. And we will update the scroll values over mouse wheel action after rendering the PDF pages in the PDF Viewer. So, there may be some delay while scrolling the pages using the mouse wheel action. 
 
 
And our online demo serviceUrl(https://ej2services.syncfusion.com/production/web-services/api/pdfviewer) is only for demo purposes. So, we suggest you create your own web service using the below KB link. We have shared the web service for your reference. 
 
 
  
 
Please refer to the following link to create the PDF Viewer service  
  
 
 
 
 
 
Kindly try this and revert us, if you have any concerns. 
 
 
Regards, 
Dhivya. 


TE techlandandyzhang October 20, 2021 04:18 AM UTC

Hi, Dhivya,

Same problem encountered when I used my own server for testing.

And I found that it was relate to Dynamic component loader. In my Demo samples, there was one to display PDFView directly, which works well without problem.

However, this problem happened if loading PDFView by Dynamic Component loader, furthermore, it affected all pages with progress bar.


Has Problem Case:



No Problem Case:







DM Dhivyabharathi Mohan Syncfusion Team October 21, 2021 09:10 AM UTC

Hi Techlandandyzhang, 
  
  
We were able to reproduce the reported issue “Delay in scrolling the pages on mouseWheel action”. We will analyze further and provide the further details on October 25, 2021. 
  
  
Regards, 
Dhivya. 


DM Dhivyabharathi Mohan Syncfusion Team October 25, 2021 12:43 PM UTC

Hi Techlandandyzh,  
 
 
On analyzing the provided sample, we found that the violation occurs due to the Grid Control. We have checked without the Grid, the PDF Viewer scrolling action is working properly. Currently we are checking this issue and will update further details on October 27, 2021. 
 
 
Regards, 
Dhivya. 


DM Dhivyabharathi Mohan Syncfusion Team October 27, 2021 07:31 AM UTC

Hi Techlandandyzh, 
 
 
On further checking the sample, you are loading 1000 records and 12 columns to the Grid. So, it creates 1000 tr elements in the DOM. If the DOM contains more elements, then performing any action on the DOM leads to a performance issue. This is the default behavior.  
 
 
The only way to avoid this performance issue that we need to reduce the number of elements rendered in the DOM. You can achieve this by using the Paging or Virtualization feature of Grid. We have shared the UG documentation links for your reference. 
 
 
                          
 
 
Please get back to us if you need further assistance on this.  
 
 
Regards, 
Dhivya. 


CR Carlos Reche November 18, 2021 09:44 AM UTC

The same problem is happening to me, but I am only using the pdf-viewer. When I open a document the scrolling within it is very slow and when I close the document this problem persists throughout the web, when before opening the viewer it did not happen


DM Dhivyabharathi Mohan Syncfusion Team November 19, 2021 01:16 PM UTC

Hi Carlos, 
 
 
We have checked with the PDF Viewer in Angular application, and we were unable to replicate the reported scrolling performance issue. We have shared the sample in which we tried to replicate this issue. 
 
 
 
 
Could you please try the sample and let us know whether you are facing the same issue with the provided sample? And kindly share the modified sample in which you are facing this issue. It will be helpful for us to investigate further and provide the details at the earliest. 
 
 
Regards, 
Dhivya. 


CR Carlos Reche November 23, 2021 07:28 AM UTC

I have not found differences in my project, although yours works fine. Could it be related to the scroll?warnings.png


CR Carlos Reche November 24, 2021 07:43 AM UTC

In our project we have Angular 6, is there a problem? or should we use some exact version of @syncfusion/ej2-angular-pdfviewer and its dependencies?


DM Dhivyabharathi Mohan Syncfusion Team November 24, 2021 12:42 PM UTC

Hi Carlos, 
 
 
If the wheel event is bound in the DOM element, then it will cause a delay while scrolling the page in our PDF Viewer control. We were unable to replicate the same issue with the sample which we have shared in the previous update. We suspect that this issue is not due to the version-based. So, could you please share the modified sample in which you are facing this issue? It will be helpful for us to investigate further and assist you better. 
 
 
Regards, 
Dhivya. 


CR Carlos Reche November 25, 2021 09:59 AM UTC

When removing encapsulation: ViewEncapsulation.None​, everything appears to have worked correcty, makes sense?

When removing encapsulation: ViewEncapsulation.None, everything appears to have worked correctly. makes sense?


When removing encapsulation: ViewEncapsulation.None, everything appears to have worked correctly. makes sens


DM Dhivyabharathi Mohan Syncfusion Team November 26, 2021 01:01 PM UTC

Hi Carlos, 
  
  
Thank you for your update. We are glad to know that the reported issue is resolved. However, we suspect that while using the ViewEncapsulation.None will affect the HTML element present in the application. So, the performance issue occurs. So, we suggest you remove the encapsulation used in your application to get the issue resolved. We have shared the reference link. 
  
  
  
  
Please revert to us, if you need further assistance. 
  
  
Regards, 
Dhivya. 


CR Carlos Reche March 3, 2022 12:48 PM UTC

Hello, 


it seemed that the problem was solved, but it is not, it keeps happening to me and every time I open a viewer on the web, performance drops considerably. It looks like an event listener that gets stuck, but I'm not sure. I urgently need a solution since I have users using the tool and having to close the web when the performance is unbearable. Information attached.

I have no possibility to compile with aot. And the application does not have and cannot have Lazy Loading.


node: v12.16.1

npm: 6.13.4

angular: 6.1.10

syncfusion: 18.4.44

app theme: bootstrap

syncfusion-theme: material


Attachment: Synfucion_pdfviewer_2c0a0f33.zip

CR Carlos Reche March 3, 2022 02:47 PM UTC

More info.


Attachment: eventlistener_c6d59067.zip

DM Dhivyabharathi Mohan Syncfusion Team March 4, 2022 10:11 AM UTC

Hi Carlos, 
 
We have checked by integrating the PDF Viewer and the File Manager component in the Angular sample and the reported issue is not replicated on our end. We have shared the Angular sample and web service in which we tried to replicate the reported issue. 
 
 
 
Could you please try with the provided sample and let us know whether you are facing the same issue? Else we can set up a web meeting and provide the details. Please let us know your availability. We will make every effort to have this scheduled on a date and time of your convenience.  
 
Regards, 
Dhivya. 


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