SMK / Initialization

Initializing the Configuration Sources

This value controls the sources of configuration that are used to setup the map. These configuration sources are each ultimately resolved into an object that is interpreted by the SMK configuration schema.

The resolved configuration objects are merged together, and the final merged object is used to setup the map (merging rules).

The default value for the source directives is [ '?smk-' ], which tells SMK to look at the URL of the host page for any parameters that start with smk-. If this behaviour is undesirable, then the configuration source should be changed.

smk-config Attribute

Not required, default is “?smk-”

Used by the SMK <script> element. It contains a list of source directives, separated by “|” The sources are loaded left to right, with the configuration from later sources overriding configuration from earlier sources. A source directive cannot contain “|”, and there is no escaping mechanism.

Example showing all types of directives:

<script src="smk/dist/smk.js"
    smk-container-sel="#smk-map-frame"
    smk-config="smk-config.json | {"viewer":{"baseMap":"Streets"}} | ?smk- | zoom=7"
></script>

config Option

Not required, default is “[ '?smk-' ]”

Used by SMK.INIT. The value is an array of source directives. The sources are loaded left to right, with the configuration from later sources overriding configuration from earlier sources.

Example showing all types of directives:

SMK.INIT( {
    containerSel: '#smk-map-frame',
    config: [
        'smk-config.json',
        { viewer: { baseMap: 'Streets' } },
        '?smk-',
        'zoom=7'
    ]
} )

Source Directives

A source directive is one of the following:

• URL
• Object
• JSON
• Parameter
• Alias

URL Directive

A valid URL that is assumed to point a file containing a JSON-encoded SMK configuration object.

JSON Directive

SMK configuration as a literal JSON string. No newlines should be in the JSON, unless they are escaped inside quoted strings.

This is only useful in the smk-config Attribute, and the JSON blob must be encoded by encodeURIComponent.

Object Directive

SMK configuration as a Javascript object literal.

This is only useful in the config Option.

Parameter Directive

A sequence that start with ?. It may be followed by any character string, like ?smk-, or ?foo, or ?##. The characters following the ? are the Prefix. A ? with nothing following, means that the Prefix is an empty string.

When this directive is encountered, the URL of the current document is parsed, and the parameter section is extracted. The parameter section is parsed according to the usual rules (split by & into items, and split each item by = into [key, value] pairs). Then if a parameter key starts with the Prefix, the rest of the parameter key is considered to be an alias directive along with the parameter value.

A Prefix that is an empty string matches any parameter key.

Alias Directive

A string consisting of an NAME=ARGUMENTS. These are aliases for a blob of SMK configuration. The aliases always resolve to some chunk of SMK config.

The NAME is one of:

• config
• viewer
• extent
• center
• ll
• z
• query
• layer
• active-tool
• show-tool
• hide-tool
• show-layer
• hide-layer

config Alias

• config=JSON-LITERAL

  The JSON-LITERAL is parsed as JSON that is assumed to be SMK configuration.

• config=URL

  Fetch the resource at URL that is assumed to be a SMK configuration JSON blob.

viewer Alias

• viewer=leaflet

  Set the viewer type to leaflet.

• viewer=esri3d

  Set the viewer type to esri3d.

extent Alias

• extent=MIN-LONGITUDE,MIN-LATITUDE,MAX-LONGITUDE,MAX-LATITUDE

  Sets the initial extent of map.

center Alias

• center=LONGITUDE,LATITUDE,ZOOM

  Sets the initial center point of the map, and the zoom level.

ll Alias

• ll=LONGITUDE,LATITUDE

  Sets the initial center point of the map.

z Alias

• z=ZOOM

  Sets the initial zoom level of the map.

query Alias

• query=LAYER-ID

  Configures a query object that finds all features on the layer, and a matching "query" tool, and sets the tool automatically active at startup.

• query=LAYER-ID,and,CLAUSE[,CLAUSE]*

• query=LAYER-ID,or,CLAUSE[,CLAUSE]*

  LAYER-ID must refer to a layer defined in the "layers" configuration.

  CLAUSE is one or more expressions of one of these forms:

  • ATTRIBUTE = VALUE (equals)
  • ATTRIBUTE ~ VALUE (contains)
  • ATTRIBUTE ^~ VALUE (starts with)
  • ATTRIBUTE $~ VALUE (ends with)
  • ATTRIBUTE > VALUE (greater than)
  • ATTRIBUTE < VALUE (less than)
  • ATTRIBUTE >= VALUE (greater than or equal)
  • ATTRIBUTE <= VALUE (less than or equal)

  ATTRIBUTE is an attribute name valid for the layer.

  VALUE is either:

  • a JSON-encoded literal (like 123, 123.456, "abc", true, false, or null)
  • ? (get this value from user)
  • @ (let user select from unique values for this attribute)

  Mulitple clauses are joined with either and or or.

  Configures a query object for the layer, and a matching "query" tool, and sets the tool automatically active at startup.

layer Alias

• layer=esri-dynamic,URL,MPCM-ID,TITLE (currently not functional)

  Add a "esri-dynamic" layer. TITLE is optional.

• layer=wms,URL,LAYER-NAME,STYLE-NAME,TITLE

  Add a "wms" layer. STYLE-NAME, and TITLE are optional.

• layer=vector,URL,TITLE

  Add a "vector" layer. TITLE is optional.

active-tool Alias

• active-tool=TOOL,INSTANCE

  Make TOOL active when the map starts. INSTANCE is optional.

show-tool Alias

• show-tool=TOOL[,TOOL]*

  Enable these TOOL s.

• show-tool=all

  Enable all tools.

hide-tool Alias

• hide-tool=TOOL[,TOOL]*

  Disable these TOOL s.

• hide-tool=all

  Disable all tools.

show-layer Alias

• show-layer=LAYER-ID[,LAYER-ID]*

  Set the visibility flag for the layers with these LAYER-ID s to true.

• show-layer=all

  Set the visibility flag for all configured layers to true.

hide-layer Alias

• hide-layer=LAYER-ID[,LAYER-ID]*

  Set the visibility flag for the layers with these LAYER-ID s to false.

• hide-layer=all

  Set the visibility flag for all configured layers to false.