Support property functions for icon-image

[jhurlb]

Hey everyone,

We've been using mapbox-gl for a bit now and rely on icon-image property functionality to draw our symbols based on a property value. The property tag has worked on versions 0.22.0 to 0.31.0. Since 0.32.0 this functionality seems to be removed. I've looked around and can't find anything that says it was removed. I know the docs say that data driven styling doesn't work for this tag, but it has worked for many versions.

mapbox-gl-js version:
0.22.0 -> 0.31.0 works
0.32.0 + broken

Browser/OS version:
Chrome Version 56.0.2924.87 on Mac OS X 10.11.6

Steps to Trigger Behavior

1. use icon-image with a property

"layout" : {
    "icon-image" : {
        "property" : "m",
        "stops"    : [
            [{
                zoom  : 0,
                value : 0
            }, ""],
            [{
                zoom  : 12,
                value : 1
            }, "marker-{c}-{d}"]
        ]
    }
}

The above example results in layout.icon-image: property functions not supported since 0.32.x

Expected Behavior

Using property for icon-image functions as it has for many versions.

Actual Behavior

Using property for icon-image results in layout.icon-image: property functions not supported since 0.32.x

[sondreb]

Attempted to upgrade from 0.31 to 0.33, getting the same type of exceptions on other properties as well, such as "line-width".

[jfirebaugh]

The error is correct; line-width and icon-image have never supported property functions. If they appeared to be working in prior versions, it was by accident. You'll need to remove the use of property functions until they are supported. That work is being tracked in #3045 (line-width) and #4304 (icon-image).

[jfirebaugh]

I guess we didn't have a tracking issue for icon-image -- we can repurpose this issue for that.