Please refer to the Web map specification topic for an updated version of the web map specification.
The web map data is a string of JSON defining how an ArcGIS web map should look and behave.
The web map data lists the basemap, operational layers, and bookmarks to be used in the web map. It also contains information about pop-up windows and layer styling overrides to be used in the web map. A version property allows you to supply the version of the web map JSON format being used.
The following is the basic structure of the web map data. Each object listed in <> has its own page in this help system.
{
"operationalLayers": [
{
<operationalLayer>
},
{
<operationalLayer>
}],
"baseMap": {
"baseMapLayers": [{
<baseMapLayer>
},
{
<baseMapLayer>
}],
"title": "Topographic"
},
"bookmarks": [
{
<bookmark>
},
{
<bookmark>
}
],
"version": "1.7"
}Basemaps give the web map a general geographic context, whereas operational layers contain proprietary or thematic information. The web map data holds two arrays of layers: one for operational layers and one for basemaps. Within the arrays, layers are drawn based on their index position. The first layer in the array is the first layer drawn, the next layer in the array is drawn on top of it, and so on.
Basemap layers can be drawn above or beneath the set of operational layers, but they cannot appear between operational layers.