setAPIKey: Copy and Customize HTML and JavaScript Code for GE Plugin...

In duncantl/RKML: Simple tools for creating KML displays from R

Description

These functions provide access to the HTML and JavaScript code that provide templates for creating a Web page with a Google Earth (GE) plugin instance embedded within it. The templates are provided as part of the RKML package and need to be customized in different ways to present the plugin and text and controls the author desires. While most of the content is context-specific, the templates provide the basic framework which can be easily customized and facilitate the initial work which can be hard to remember.

setAPIKey inserts the authors own Google Earth API key into the HTML document so that the basic GE code can be loaded. It uses the HTML document we provide in the package by default, but an alternative can be provided by the author. It will replace any existing key, so can be used to customize a page found on the Web, for example.

copyPluginJSCode retrieves the template JavaScript code for the plugin and either writes it to a file or returns it as text. This function can also modify the code to load a KML document into the GE plugin instance.

Usage

setAPIKey(key = getOption("GoogleEarthAPIKey",  Sys.getenv("GOOGLE_EARTH_API_KEY")), 
           doc = system.file("pluginTemplate", "gePluginTemplate.html", package = "RKML"))

copyPluginJSCode(to = "geInitialization.js",  kml = character(),
                 multipleGEs = FALSE,
                 source = system.file("pluginTemplate",
                                      if(multipleGEs)
                                        "geMultiInitialization.js"
                                      else
                                        "geInitialization.js",
                                      package = "RKML"))

Arguments

key	a string giving the Google Earth API key for the particular host on which the document will be made available. Each key is specific to a particular domain. You can obtain a key for free at http://code.google.com/apis/maps/signup.html. The caller can specify this explicitly. However, it is often more convenient to retrieve it from R's global options, using the option name GOOGLE_EARTH_API_KEY. We would set this in our R startup script, i.e. the .Rprofile file.
doc	a string giving the name of the HTML file to use as the template HTML for the Web page. If this does not alreay have a script element in the head of the document to load the GE code, setAPIKey adds it. Otherwise, the function inserts the key.
to	the name of the file to write the code to. This can be NA in which case the code is returned as a character vector and the caller can process it subsequently and perhaps insert it directly into an HTML document.
kml	a character vector giving the names of one or more KML files or URLs that are to be loaded into the Google Earth plugin instance(s). These are added to the initialization callback that is invoked by JavaScript when the GE instance has been created. Currently, we load them all into the same GE if multipleGEs is FALSE. If it is TRUE, the kml vector should have names that correspond to the id values of the HTML elements into which the KML documents are to be loaded.
source	a string giving the name of the file containing the JavaScript code.
multipleGEs	a logical value that is only used if kml contains more than one file name or URL. If this is FALSE, each of the KML documents is loaded into the same GE instance.

Value

setAPIKey returns a parsed XML docment. You can process this further and then write it to a file using saveXML.

copyPluginJSCode either writes the JavaScript code to a file (specified by to) or returns the code as a character vector.

Author(s)

Duncan Temple Lang

Examples

  doc = setAPIKey("ABCDEF")
  saveXML(doc, tempfile())

  txt = copyPluginJSCode(NA, "http://www.omegahat.org/RKML/JSM2011/tas1970.kml")

  txt = copyPluginJSCode(tempfile(),  "http://www.omegahat.org/RKML/JSM2011/tas1970.kml")  

  base = "http://www.omegahat.org/RKML/JSM2011/imageAnimation"
  docs = c(ge.timeslice = "timeslice_current.kml",
           ge.RCM = "gcmrcm_current.kml")
  txt = copyPluginJSCode(NA, structure(sprintf("%s/%s", base, docs),
      	           	         	names = names(docs)))

duncantl/RKML documentation built on May 15, 2019, 5:31 p.m.