Webview:eval(expr) method
Execute JavaScript code in the current top level document rendered in the WebView.
Parameters
expr
A string representing a valid Javascript expression to be evaluated.
Return value
This function returns a Task instance.Once finished, the Task will return the result of the Javascript execution as a
string, encoded using JSON.
Example
local ui = require "ui"
require "webview"
-- create a simple Webview
local win = ui.Window("Webview:eval() sample", 640, 480)
local Webview = ui.Webview(win, "https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/PI", 0, 50, 640, 500)
local button = ui.Button(win, "Evaluate Javascript Math.PI")
button:center()
button.y = 10
function button:onClick()
Webview:eval("Math.PI").after = function(value)
ui.info(value, "Math.PI value from Javascript")
end
end
-- update user interface
ui.run(win):wait()