Difference between revisions of "JS.eval"

From GiderosMobile
(removed language stuff and added example from sinistersoft)
(added examples)
Line 12: Line 12:
 
'''code''': (string) JavaScript code to execute<br/>
 
'''code''': (string) JavaScript code to execute<br/>
  
=== Example ===
+
=== Examples ===
 +
'''Opens an url'''
 +
<source lang="lua">
 +
JS.eval([[
 +
window.open('my.url')
 +
]])
 +
</source>
 +
 
 +
 
 +
'''In your html5 exports use this to detect if you are in light or dark mode - to change your app or game colors to suit...'''
 +
<source lang="lua">
 +
sysDark=-1
 +
 +
-- device={application:getDeviceInfo()}
 +
-- device[1]=="Web"
 +
-- only do the next line if html5 export
 +
if JS.eval("window.matchMedia('(prefers-color-scheme:dark)').matches")=="true" then sysDark=1
 +
else sysDark=0
 +
end
 +
</source>
 +
You will end up with sysDark being -1 for 'don't know', 0 for 'light' and 1 for 'dark'.
 +
 
 +
 
 
'''Sometimes you may not want the user to leave the game without giving a warning that they will lose information, here is code that will allow you to do this on html5 exports:'''
 
'''Sometimes you may not want the user to leave the game without giving a warning that they will lose information, here is code that will allow you to do this on html5 exports:'''
 
<source lang="lua">
 
<source lang="lua">

Revision as of 04:38, 8 September 2021

Available since: Gideros 2016.10
Class: JS

Description

Executes arbitrary JavaScript code on HTML5 platform.

JS.eval(code)

Parameters

code: (string) JavaScript code to execute

Examples

Opens an url

JS.eval([[
	window.open('my.url')
]])


In your html5 exports use this to detect if you are in light or dark mode - to change your app or game colors to suit...

sysDark=-1
 
-- device={application:getDeviceInfo()}
-- device[1]=="Web"
-- only do the next line if html5 export
if JS.eval("window.matchMedia('(prefers-color-scheme:dark)').matches")=="true" then sysDark=1
else sysDark=0
end

You will end up with sysDark being -1 for 'don't know', 0 for 'light' and 1 for 'dark'.


Sometimes you may not want the user to leave the game without giving a warning that they will lose information, here is code that will allow you to do this on html5 exports:

if JS then
	JS.eval([[
		window.saveWarning=false;
		window.saveWarningListener = (e) => {
			if (window.saveWarning==true) {
				e.preventDefault();
				e.returnValue='';
			}
		};
		window.addEventListener('beforeunload', saveWarningListener);
	]])
end

function saveWarning(f)
	if JS then
		if f then JS.eval("window.saveWarning=true;")
		else JS.eval("window.saveWarning=false;")
		end
	end
end