Symbol Dictionary Rendering Legend Support

[sgordon]

I would *love* it if the Dictionary Renderer symbology method supported Legends. I have a few Symbol Dictionaries that I use and I find that their usefulness is really diminished by the fact that they don't support legends. A new user requires an orientation or to be sent a copy of a hand-made legend. 

The legend couldn't show all possible symbol combinations, but if the user could define which symbols to add to the legend this would make the Symbol Dictionaries that much more useful. The Dictionary Configuration JSON might contain a list of Symbol Keys which would used by the legend to render symbols, similar to the output of the standard Dictionary Script. 

Anything that lets the Legend in ArcGIS Pro render symbols used in a Dictionary style package.

[CraigWilliams]

Defining the list of items to show is how we've been thinking about this. You mention it as part of the configuration, but we've been considering it as part of the layer. Maybe the configuration could specify the default for new layers, but there are cases - especially with military symbology - where the use cases vary so widely that it's hard to come up with one sensible default list.

[JonathanDandois]

+1 for this!  I know this idea is posted under ArcGIS Pro, but I think it would be great for published services as well.  I'm not in military, but find a lot of value in Dictionary Symbology (DS) for complex asset surveys on our campus - I wonder if there are others like me?

For example, I've used DS to build a PDF map and a web map for a door survey on our campus where each exterior door might have one of half a dozen different symbology keys based on the door's survey status (different colored door SVG icons), its installed opening hardware (one or more icon symbols with consistent XY offset around the door), which floor it provides egress to (text from an attribute field).

Or, I'm currently working on a light pole survey for crews to use in Field Maps where I need to show a different icon for the style of light, what additional hardware it has, and the survey status of different elements, all tied to attribute fields. 

Maybe there is a way to have a new key:value in the `meta` table that is `dictionary_legend` that can use JSON to spoof the Legend object for a feature service? Something like an array of objects that also references the symbology keys.  

Certainly this can't cover all possible combinations, but maybe its something?

[
  {
    "keys": "lightPost", 
    "title": "Light Post"
  },
  {
    "keys": "lightPost;banner", 
    "title": "Light Post with banner"
  }  {
    "keys": "lightPost;disabled", 
    "title": "Light Post - disabled"
  }
]

[LinwoodCreekmore]

I agree; having a legend for a layer that uses dictionaries for symbologies would be great. Not sure if this is possible, but if ESRI's backend knows what to render in the actual Map, is it possible to use the extent and maybe a "show in Legend" feature of some sort to configure it? Even if you used the military dictionary, showing the top 5 legend icons (by occurrence) would be ideal. If someone wanted more, they could configure. 

However it is done, anything is better than no legend.