Migrating existing JavaScript(ExtendScript) to UXP Script

SI

Differences

JavaScript(Objects also have ExtendScript)

UXP Script

Appicable To

1

subscript operator [ ]:Collection objects returned by InDesign like documents and paragraphs will not support subscript operator [ ] to access element at a particular index.The alternative is to use the method by name item()Objects like app.selection which is of type Array will support subscript operator.

for (j = 0; j < app.selection[0].paragraphs.length; j++){               var  item = app.selection[0].paragraphs[j];}

for (j = 0; j < app.selection[0].paragraphs.length; j++){               var  item = app.selection[0].paragraphs.item(j);}

All Versions

2

Object.constructor.name:Object.constructor.name which is a standard property in JS will return empty string ("") for InDesign scripting DOM objects. Alternative is to use the object.constructorName property.

switch(myPageItem.constructor.name){                    case "Rectangle":                    case "Oval":                        ...                        break;   }

switch(myPageItem.constructorName){                    case "Rectangle":                    case "Oval":                        ...                        break;   }

Prior To 18.4

3

Comparison operators(== and ===):Comparison operators(== and ===) on InDesign DOM objects will always return false unless the objects have same reference. Instead use method equals()

if (myPath.pathType == PathType.closedPath) { ... }

if (myPath.pathType.equals(PathType.closedPath)) { ... }

All Versions

4

instanceof:The instanceof keyword isn't supported for InDesign DOM objects. Instead using object.constructorName property.

if (app.selection[0].paragraphs[0].appliedParagraphStyle.parent instanceofParagraphStyleGroup) { ... }

if (app.selection[0].paragraphs.item(0).parent.constructorName =="ParagraphStyleGroup") { ... }

Prior To 18.4

5

Global object 'document':global object 'document' is unsupported now instead use app.activeDocument

document.findText()

app.activeDocument.findText()

All Versions

6

ActiveScript: app.activeScript

app.activeScript returns current running script as file object on which we can access other properties.

app.activeScript returns the path of the current script as a string. No other properties can be accessed on app.activeScript 

Prior To 18.4

7

Fetching the InDesign Server arguments passed to a script.

var myArg = app.scriptArgs.getValue("argumentName");

let arguments = script.args; Learn More

18.4 Onwards