FileManager navigation tree fails to expand child nodes inside Dialog using raw JS

Setup: We construct ej.filemanager.FileManager via raw JS (not the Blazor wrapper) and append it inside an ej.popups.Dialog content area. The dialog opens from a button on a legacy ASP.NET WebForms page.

Symptom: The file grid renders correctly. The navigation tree shows only the root node. Clicking the chevron next to the root node fires the expected POST request to our backend, the response returns valid child folder data (verified in Network tab), but no child <li> elements are inserted into the tree DOM. The chevron rotates visually but the tree's <li> keeps the e-collapsed class.

What we've tried (none fixed it):

  1. animationSettings: { effect: 'None' } on the dialog
  2. refreshLayout() after first AJAX success
  3. refreshFiles() after mount (throws Cannot read properties of undefined (reading 'element'))
  4. Deferred FileManager creation via setTimeout post-dialog-open
  5. Setting explicit path constructor option

Comparison: The same FileManager rendered via the Blazor SfFileManager wrapper (also inside a dialog) populates the tree correctly. Backend response is byte-identical between both contexts.

Question: Is there a known requirement when constructing the JS-mode FileManager inside a Dialog? Is there a config option, lifecycle hook, or initialisation step the Blazor wrapper performs that we need to replicate in raw JS?

Note: I've been testing this on Google Chrome.


1 Reply

PS Praveen Sellappan Syncfusion Team April 20, 2026 02:26 PM UTC

Hi Nick Shaw,


Greetings from Syncfusion Support.


Query 1: FileManager navigation tree fails to expand child nodes inside Dialog using raw JS


Based on the issue you described, we prepared a local sample using the File Manager component rendered inside the Syncfusion Dialog component.


We tested the sample using the latest Syncfusion version in Microsoft Edge and Google Chrome. During our testing, we did not encounter any issues with the File Manager navigation tree, such as child nodes failing to expand inside the Dialog, as described in your report.


In the sample, the File Manager is refreshed when the Dialog is opened to ensure it properly adjusts to the Dialog’s width and height. Even with this setup, we were unable to reproduce the reported behavior on our end.


We have attached the sample for your reference. Kindly review it and check whether it aligns with your configuration and reproduces the issue.


Sample: https://stackblitz.com/edit/h6bmofds-9sc9g3gj?file=index.js


If the issue still persists, please share the following details to help us investigate further:


  • Whether you are able to reproduce the issue using the attached sample
  • The Syncfusion package version you are using
  • The environment in which the application is tested (browser and OS)
  • A video demonstrating the issue
  • Any console errors observed while running the sample
  • Whether you are using a Syncfusion file system provider or a custom provider
  • If using the Syncfusion provider, please share the provider name
  • If possible, a minimal issue-reproducible sample


These details will help us analyze the issue more effectively.


Query 2: Is there a known requirement when constructing the JS-mode FileManager inside a Dialog? Is there a config option, lifecycle hook, or initialisation step the Blazor wrapper performs that we need to replicate in raw JS?


There is no additional configuration or special initialization step required when using the JavaScript FileManager inside a Dialog compared to the Blazor wrapper.


However, please ensure the following when rendering the FileManager inside a Dialog in JS mode:


  • The FileManager should be initialized or refreshed after the Dialog is opened so that it can correctly calculate its dimensions.
  • Calling the refresh() method on the FileManager after the Dialog becomes visible ensures proper layout and interaction.


document.getElementById('openBtn').onclick = function() {

    dialogObj.show();

   

    filemanagerInstance.refresh();

};

 

Please review the shared details and let us know if you need any further assistance.


Regards,

Praveen Sellappan



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