Sidecars take long to load scrolling from one to the other

Question

I have a StoryMap that I've created that has about 20 sidecars within it pointing to the same webmap. When scrolling from one to another it takes quite some time for the next one to load. Is there a solution to this or is it just a product of there being a lot of sidecars in the StoryMap itself? I can provide the link if that helps anyone help me with this issue.

oevans_storymaps · Answer

@MichaelUnterholzner24 -- The issue you are seeing is caused by the initial loading of the map since it has 80 (!!!) layers in it.

There is some overhead associated with loading each layer in a map (even for layers that are not initially visible), and 80 is a very large number of layers for a single map. This is true not only loading the map in a StoryMap, but anywhere -- opening the map once in the ArcGIS map viewer it takes about 15-20 seconds on a fast computer/network (try that here). When you have that map added in multiple sidecar blocks in the same story, you incur all that overhead multiple times.

I don't think your map needs to have that many layers for you to tell your story. In general, it's not good practice to break up a single GIS dataset into multiple layers for different areas (e.g., Filipino-Alameda, Filipino-Contra Costa, Filipino-Los Angeles, etc.). Doing this can bloat a web map very quickly, and it works against many of the optimizations and management tools built into the ArcGIS platform's web mapping tech. There are many other methods that can be used to focus a reader's attention on particular area such as using mask layers, a boundary layer, labels, multivariate layer styles, or a combination of these techniques.

Keeping the number of layers below 10 is usually advisable for any map used in a story.

You'll notice once the map is loaded in a particular section of your story, it's very smooth as you move between immersive slides. Using the same map in sequential slides within the same sidecar block does not require the map to be reloaded, but using the same map in different sidecar blocks does.

I think there are a few things you could try to improve the situation:

* Use your current map, but redo your story so it uses a single sidecar section so the map would only need to load once. You can still have headings and story navigation links to each section as you have now.
* Keep the story organized in multiple sidecar blocks as it is now, but create a map for each section of your story so that each map has a handful of layers, so they will load in a reasonable amount of time. 
* Aggregate all the common layers (county layers, Arabic, Filipino, Cantonese, etc.) into a much smaller set of master layers, and use a boundary layer or mask layers or other techniques to visually focus the map on each area in section of the story.

I think either the 2nd or 3rd option would be better in your case because your current map has such a large number of layers. My guess is that people on slower connections and/or mobile devices may have a bad experience if you keep the current map because the map still has to load once.

Hope this is helpful! Let me know if you have any questions.

MichaelUnterholzner24 · Answer

Here's the link: https://storymaps.arcgis.com/stories/11a436a00c60499fb8e408c36d4eff82

oevans_storymaps · Answer

@MichaelUnterholzner24 -- Yes, if you could share your story with Everyone and provide a link, we can try to take a look to see if we notice anything. It may be one or more layers in your map that are not performing well.