Writing the Record to plist file, then read it back

Scripting Forums AppleScript | Mac OS X
#1

Hello,

I can write the record {aString:“Hello,word!”, anInteger:1, aReal:3.14} to the plist file this way:


{aString:"Hello,word!", anInteger:1, aReal:3.14} -- my test record

do shell script "defaults write my.domain myRecord -dict 'aString' 'Hello,word!' 'anInteger' '1' 'aReal' '3.14'"

My request for help is: how can I get my record back to my Apple-script, effectively?

Here is my attempt, which returns structured text instead of the record:

do shell script "defaults read my.domain myRecord"

the result is following:

“{
aReal = "3.14";
aString = "Hello,word!";
anInteger = 1;
}”

Note that the order of entries is different when reading and writing!!!

Also, following gives to me the type (dictionary in this case) of myRecord in the plist file:


do shell script "defaults read-type my.domain myRecord"
--> "Type is dictionary"
#2

I got it! (with help from user @CK in the previous topic) :slight_smile:


use AppleScript version "2.4" -- Yosemite (10.10) or later
use framework "Foundation"
use scripting additions

set resultString to (do shell script "defaults read my.domain myRecord")

my (NSString's stringWithString:resultString)'s propertyList() as record

Now, I have other problem: I can indicate the Type of every Value when writing to plist file, but the snippet above returns all Values as string!!!


use AppleScript version "2.4" -- Yosemite (10.10) or later
use framework "Foundation"
use scripting additions

-- write
do shell script "defaults write my.domain myRecord -dict 'aString' -string 'Hello,word!' 'anInteger' -integer '1' 'aReal' -float '3.14'"
delay 1

-- read back
set resultString to (do shell script "defaults read my.domain myRecord")

my (NSString's stringWithString:resultString)'s propertyList() as record
--> {aReal:"3.14", aString:"Hello,word!", anInteger:"1"}

Is this my flaw or a flaw in AppeScriptObjC bridging? In any case, how to fix it, if possible?

#3

The values are string because you write all values as string (which is the default).

To write specific types you have to add flags like -int and -float

do shell script "defaults write my.domain myRecord -dict 'aString' 'Hello,word!' 'anInteger' -int '1' 'aReal' -float -'3.14'"

An alternative to read the data is

set plist to do shell script "defaults read my.domain myRecord"
set plistData to my ((NSString's stringWithString:plist)'s dataUsingEncoding:4)
set theRecord to (current application's NSPropertyListSerialization's propertyListWithData:plistData options:0 format:(my NSPropertyListOpenStepFormat) |error|:(missing value)) as record

Edit:

I noticed that in both cases the values are still string when reading back the data even without coercing to record. I regard this as a bridging issue

Second edit:

This reads the data correctly

set plistPath to POSIX path of (path to library folder from user domain) & "Preferences/my.domain.plist"
set plistData to my (NSData's dataWithContentsOfFile:plistPath)
set plist to (my (NSPropertyListSerialization's propertyListWithData:plistData options:0 format:(my NSPropertyListXMLFormat_v1_0) |error|:(missing value)))
set theRecord to (plist's objectForKey:"myRecord") as record
#4

No, I am writing correctly, and my entry matches yours (as I checked in BBEdit), you are just using the shortened form of option names.

Excellent! Thanks for the help, it works.

Now it remains to understand only one thing: how to force defaults command not to add garbage from RAM to the tail of a real number when converted to a float. :slight_smile:

use AppleScript version "2.4" -- Yosemite (10.10) or later
use framework "Foundation"
use scripting additions

-- write
do shell script "defaults write my.domain myRecord -dict 'aString' -string 'Hello,word!' 'anInteger' -integer '1' 'aReal' -float '3.14'"
delay 1

-- read back
set plistPath to POSIX path of (path to library folder from user domain) & "Preferences/my.domain.plist"
set plistData to my (NSData's dataWithContentsOfFile:plistPath)
set plist to (my (NSPropertyListSerialization's propertyListWithData:plistData options:0 format:(my NSPropertyListXMLFormat_v1_0) |error|:(missing value)))
set theRecord to (plist's objectForKey:"myRecord") as record

--> {aString:"Hello,word!", aReal:3.140000104904, anInteger:1}
#5

This is the normal imprecision of floating point numbers.

Please read Is floating point math broken? on Stackoverflow

#6

It’s annoying.

Because this means: you have to write a real in text form, then after reading the value, convert it back to a real, and for the correct reverse conversion on remote computers, you will have to define a local setting for the decimal separator.