可可脚本：接受并返回NSData [英] Cocoa Scripting: Accept and return NSData

问题描述

为了支持可编写脚本的Mac应用程序中的二进制数据交换，我希望尽可能使用AS-ObjC桥接器以NSData的形式接收和传递数据。

In order to support binary data exchange in my scriptable Mac app, I like to make it possible to receive and deliver data as NSData, using the AS-ObjC bridge, if that's possible.

例如，我想在AppleScript中使此代码成为可能：

For instance, I like to make this code possible in AppleScript:

use framework "Foundation"

set theData to current application's NSData's dataWithContentsOfFile:"/some/binary/file"

tell application "MyApp"
    set raw value to theData
end tell

sdef包含以下值类型和属性：

The sdef contains a value-type and property for this:

<suite name="My Suite" code="Demo">
    <value-type name="ObjCNSData" code="NSDa">
        <cocoa class="NSData"/>
    </value-type>
    <class name="application" code="capp">
        <property name="raw data" code="rawD" type="ObjCNSData">
            <cocoa key="rawData"/>
        </property>

然后我将转换处理程序实现为 NSData ，类似于Sketch示例将NSColor转换为值类型 RGB颜色的方式：

I then implement the conversion handler as an extension to NSData, similarly to how the Sketch example converts NSColor to the value-type "RGB Color":

@implementation NSData(DemoScripting)
+ (NSData *)scriptingObjCNSDataWithDescriptor:(NSAppleEventDescriptor *)desc {
    id res = [desc coerceToDescriptorType:'NSDa'];
    // -> res is NULL, which is not getting me any further
}

desc的描述为：

The desc's description is:

<NSAppleEventDescriptor: 'obj '{
  'form':'ID  ',
  'want':'ocid',
  'seld':'optr'($E0A8430080600000$),
  'from':null()
}>

类似地，调用 [NSScriptObjectSpecifier _scriptingSpecifierWithDescriptor：descriptor] 也返回NULL。

Similarly, invoking [NSScriptObjectSpecifier _scriptingSpecifierWithDescriptor:descriptor] returns NULL as well.

那么，如何获取应用程序代码中的实际NSData对象？

So, how do I get to the actual NSData object inside my app code?

以及如何将NSData对象返回到AppleScript？

And how do I return a NSData object to the AppleScript?

推荐答案

Shane Stanley 确实知道一种方法，它甚至不需要我的应用程序中的额外代码-相反，可以使用以下两个转换函数在AppleScript中完成所有操作：

Shane Stanley did indeed know a way, and it does not even require extra code in my app - instead, it can all be done in AppleScript, with these two conversion functions:

use framework "Foundation"

set nsData1 to current application's NSData's dataWithContentsOfFile:"/etc/hosts"
set asData to my ASDataFromNSData(nsData1)
set nsData2 to my NSDataFromASData(asData)

on ASDataFromNSData(theData)
    set theCode to current application's NSHFSTypeCodeFromFileType("'rdat'")
    return (current application's NSAppleEventDescriptor's descriptorWithDescriptorType:theCode |data|:theData) as data
end ASDataFromNSData

on NSDataFromASData(asData)
    return (current application's NSArray's arrayWithObject:asData)'s firstObject()'s |data|()
end NSDataFromASData

看来 rdat 是用于此目的的特殊AppleScript类型，该框架会自动处理NSData的转换。但是，我找不到在AE.framework标头中声明的类型。

It appears that rdat is a special AppleScript type for this purpose, with the framework automatically handling the conversion with NSData. I can't find that type declared in the AE.framework's headers, though.

然后我仍然必须处理此 rdat 会在我的应用代码中明确输入。但是我不需要sdef中的值类型，并且可以将属性更改为：

I then still have to handle this rdat type explicitly in my app's code, though. But I won't need the value-type in the sdef, and can change the property to:

<property name="raw data" code="rawD" type="any">
    <cocoa key="rawData"/>
</property>

将数据作为 rdat 返回是相似的。我的 -rawData 方法：

Returning data as rdat is similar. My -rawData method:

return [NSAppleEventDescriptor descriptorWithDescriptorType:'rdat' data:myNSData];

这仅在我将属性类型声明为 any时有效。如果我使用 type = rdat ，脚本调试器会将该类型显示为专用的原始数据类型，但是当我尝试在其中设置或获取属性时，会出现-10000错误脚本。

This only works if I declare the property type as "any", though. If I use type="rdat", Script Debugger shows the type as a dedicated raw data type, but then I get -10000 errors when trying to set or get the property in a script.

这篇关于可可脚本：接受并返回NSData的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！