Edit JSON data in PowerShell 2.0

Question

I got a script which should write inside the json preferences data to change the auto opening from different extensions.

The first part I got from here but this script uses ConvertFrom-Json and ConvertTo-Json which is only supported in Powershell >= 3.0.

Then I found a function that imitates this Cmdlet here. Now my problem is that it is not working at all and I don't know why, because I don't get any Errors or something.

$neededFileExt = "2er"
$path = $env:LOCALAPPDATA + "\Google\Chrome\User Data\Default\Preferences"
$prefContent = Get-Content $path -Encoding utf8

I think the next two functions are the reason why it doesn't work properly.

function ConvertTo-Json([object] $prefcontent) {
    add-type -assembly system.web.extensions
    $prefs = new-object system.web.script.serialization.javascriptSerializer
    return $prefs.Serialize($prefcontent)
}

function ConvertFrom-Json([object] $prefcontent) { 
    add-type -assembly system.web.extensions
    $prefs = new-object system.web.script.serialization.javascriptSerializer
    return , $prefs.DeserializeObject($prefcontent)
}

$prefs = ConvertFrom-Json $prefContent
if (($prefs | gm).name -contains "download") {
    if (($prefs.download | gm).name -contains "extensions_to_open") {
        if ($prefs.download.extensions_to_open) { #if it has value, grab the contents
            [string[]]$existingFileExt = 
            $prefs.download.extensions_to_open.tostring().split(":")
        }
        else {
            [string[]]$existingFileExt = $null
        }
    }
    else {
        #if extensions_to_open doesn't exist, create it
        $prefs.download | Add-Member -MemberType NoteProperty -Name extensions_to_open -Value ""
        [string[]]$existingFileExt = $null
    }
    foreach ($ext in $neededFileExt) {
        if ($existingFileExt -notcontains $ext) { #only add the necessary extension if it isn't already there
            [string[]]$existingFileExt += $ext
        }
    }
    $prefs.download.extensions_to_open = $existingFileExt -join ":" 
    ConvertTo-Json $prefs -Compress -depth 100 | Out-File $path -Encoding utf8 
}

Would appreciate any suggestions or help.

my question is not a duplicate of this post because i used the function from this post but my code is not relatable

Welcome to StackOverflow! It is good that you added your code. However as it was formatted, it was broken because you added line breaks in comment lines. I fixed it and reformatted it. Hope it is now more readable. — Clijsters, Sep 06 '18 at 13:17
Please be more specific about "not working at all". What does not work? Have you tried executing parts of your script to narrow down the problem? I tried most of your code and it seemed to work fine, but I have PS 5. Find out which part of your code is not giving the expected result. — marsze, Sep 06 '18 at 13:24
To beginn with everything, worked while being in powershell 3.0 but then i needed to exchange the convertfrom-json and convertto-json into a function so im pretty sure that the other code lines are working properly. And with not working i mean that there are no file types added to the json file without giving any response back. — kaesedipp, Sep 06 '18 at 13:30
@marsze, it shouldn't be an issue that you don't have PowerShell 2 installed. You can simulate the issue by opening a PowerShell Version 2 prompt with command `PowerShell -Version 2` — iRon, Sep 06 '18 at 14:43

iRon · Answer 1 · 2018-09-06T15:24:49.180

0

PowerShell version 2 doesn't allow to expand properties directly from an object list like you do:

($prefs | gm).name -contains "download"

For PowerShell version 2 you should use the Select-Object -ExpandProperty cmdlet/parameter:

($prefs | gm | Select -ExpandProperty Name) -contains "download"

edited Sep 06 '18 at 15:24

answered Sep 06 '18 at 15:14

iRon

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ty alot right know im not at the office i write tomorrow if it works – kaesedipp Sep 06 '18 at 17:46
after reediting both lines with the code that you said would not be supported by Ps2.0 , it did not give back a error as before but it still didnt write into the json file it self. – kaesedipp Sep 07 '18 at 09:12
It should be a matter of troubleshooting and narrowing down the issue. I suggest to use the same system for testing PSv5 and PSv2 (by using the command `PowerShell -Version 2` (to exclude that the `Preferences` file simply doesn't have `Name` property containing `download`). Then ask yourself things like: does `$prefs` contain any data? Does it pass the first `if` statement (by e.g. adding a `Write-Host 'ok'`)? Does `Write-Host $prefs.download` return anything? etc. – iRon Sep 07 '18 at 09:52

Edit JSON data in PowerShell 2.0

1 Answers1