js.eval: Difference between revisions
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|version=1.10.0 | |version=1.10.0 | ||
|description= | |description= | ||
Evaluates a string as a javascript expression. Supports ECMA 2021 standard. For security, access to native types and external resources are limited. Similarly, all arrays passed in to the javascript environment are shallow copied, so changes to the array do not directly change MapTool's state. | Evaluates a string as a javascript expression within the embedded GraalVM interpreter (this is NOT the same JavaScript environment as that provided by the HTML5 functions). Supports ECMA 2021 standard. For security, access to native types and external resources are limited. Similarly, all arrays passed in to the javascript environment are shallow copied, so changes to the array do not directly change MapTool's state. | ||
Starting in 1.10.0, the context in which the javascript fragment executes is discarded when < | Starting in 1.10.0, the context in which the javascript fragment executes is discarded when <syntaxhighlight>js.eval</syntaxhighlight> returns. For setting up persistent structures, see {{func|js.evalNS}} or {{func|js.evalURI}} | ||
|usage= | |usage= | ||
< | <syntaxhighlight lang="mtmacro" line> | ||
js.eval(expression, arg1, arg2...) | js.eval(expression, arg1, arg2...) | ||
</ | </syntaxhighlight> | ||
'''Parameters''' | '''Parameters''' | ||
| Line 24: | Line 24: | ||
|example= | |example= | ||
Using {{code|js.eval}} on an {{code|expression}}. | Using {{code|js.eval}} on an {{code|expression}}. | ||
< | <syntaxhighlight lang="mtmacro" line> | ||
[r: js.eval("let a = [1,2,3]; return a[1] + args[0]", 5)] | [r: js.eval("let a = [1,2,3]; return a[1] + args[0]", 5)] | ||
</ | </syntaxhighlight> | ||
'''Output:''' | '''Output:''' | ||
< | <syntaxhighlight lang="mtmacro"> | ||
7 | 7 | ||
</ | </syntaxhighlight> | ||
|also= | |also= | ||
[[js:MapTool|JS: MapTool]]<br/> | [[js:MapTool|JS: MapTool]]<br/> | ||
[[js:MTScript|JS: MTScript]] | [[js:MTScript|JS: MTScript]]<br/> | ||
{{func|js.evalNS}}<br/> | |||
{{func|js.evalURI}} | |||
}} | }} | ||
[[Category:Javascript Function]] | [[Category:Javascript Function]] | ||
Latest revision as of 23:59, 19 September 2024
This article describes a feature or macro function that is experimental and may be subject to change.
js.eval() Function
Note: This function can only be used in a Trusted Macro
• Introduced in version 1.10.0
Evaluates a string as a javascript expression within the embedded GraalVM interpreter (this is NOT the same JavaScript environment as that provided by the HTML5 functions). Supports ECMA 2021 standard. For security, access to native types and external resources are limited. Similarly, all arrays passed in to the javascript environment are shallow copied, so changes to the array do not directly change MapTool's state.
Starting in 1.10.0, the context in which the javascript fragment executes is discarded when returns. For setting up persistent structures, see js.evalNS() or js.evalURI()
js.evalUsage
js.eval(expression, arg1, arg2...)Parameters
expression- A valid javascript fragment. It is wrapped inside an anonymous function.arg1, arg2...- Any. Will be converted to the equivalent javascript type as needed. Arguments are accessible via theargsvariable.return- Any primitive type; Complex types are converted to (JSON) strings.
Example
Using
js.eval on an expression.
[r: js.eval("let a = [1,2,3]; return a[1] + args[0]", 5)]Output:
7