Hi Owen,
Thanks for the quick response!
We want to embed a website running a screening tool based on ArcGIS JS API. The tool loads data (geometries and tables) from ArcGIS Online and performs various distance and intersect calculations to build a screening result table. The user is able to filter the results and export to PDF and Excel. The Story Map is used to explain the functionality and output of the tool.
The data is unfortunately not publicly available, so I cannot share a version of the tool that actually works without login and access to the ArcGIS Online layers.
The PDF and Excel files are created client side using different JS libraries. Both libraries are dependent on being able to initiate a file download through code, which is what is being blocked by the iframe sandbox. This is the cleanest solution, as everything runs on the client machine. Alternatively, we need to create and store the exports server side, provide a link to the user and then remove the exported files from the server once the file is downloaded. This is a bit messy and requires a rewrite of the exporting using server side libraries, which we would rather avoid if possible.
For now we have to provide a link to the tool as you suggest. However, we want to use an interactive Story Map to guide the user, and having to open new tabs messes that user experience up.
Thanks for looking into this. I hope you will be able to provide a way to allow the downloads in the future.