gpanel: A panel to hold other JavaScript things

In jverzani/gWidgetsWWW2.rapache: Toolkit implementation of the gWidgets API for use with web pages

Description

This produces a widget holding a "div" tag that other JavaScript libraries can use to place their content. There are a few reference class methods that make this possible. The div_id method returns the DOM id of the div object that is produced. The add_handler_onload method can be used to call a handler after the external libraries are loaded. This is an asynchronous call, so one need not worry that the libraries are done downloading. This call might require JavaScript commands to be processed that are not produced by a gWidgetsWWW2 handler. The add_js_queue method allows one to push such commands back to the browser. The method load_external is used to load external scripts by specifying the appropriate url(s).

Usage

  gpanel(container, handler = NULL, action = NULL, ...,
    width = NULL, height = NULL, ext.args = NULL,
    div_id = NULL)

Arguments

container	parent container
handler	optional handler bound via addHandlerChanged
action	optional value to paramaterize handler
...	passed along to add call of the container. Can be used to adjust layout parameters. May also have other uses.
width	a pre-specified width (in pixels) for the widget
height	a pre-specified height (in pixels) for the widget
ext.args	A list of extra arguments to pass to the ExtJS constructor

Value

a GPanel reference class object

Examples

w <- gwindow("windows and dialogs")
g <- ggroup(cont=w, horizontal=FALSE)

pan <- gpanel(cont=g, width=200, height=200)
## will load d3 javascript library
d3_url <- "http://mbostock.github.com/d3/d3.js?2.7.1"
## template to simply insert HTML
## div_id comes from pan$div_id()
tpl <- "
function(data, status, xhr) {
  d3.select('#{{div_id}}').html('Look ma HTML');
}
"
## more complicated example to draw a line
tpl2 <- "
function(data, status, xhr) {
var chart = d3.select('#{{div_id}}').append('svg')
    .attr('class', 'chart')
    .attr('width', 200)
    .attr('height', 200);

chart.append('line')
    .attr('x1', 25)
    .attr('x2', 200 - 25)
    .attr('y1', 100)
    .attr('y2', 100)
    .style('stroke', '#000');
}
"

cmd <- whisker.render(tpl2, list(div_id=pan$div_id()))
gpanel_load_external(pan, d3_url, cmd)

jverzani/gWidgetsWWW2.rapache documentation built on May 20, 2019, 5:19 a.m.