Text.Json notes

ninmonkey · Jan 20, 2024 · d15ca5f · d15ca5f
1 parent b10505a
commit d15ca5f
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diff --git a/...Modules/Text.Json/Attributes for conditionally ignoring properties - System.Text.Json.ps1 b/...Modules/Text.Json/Attributes for conditionally ignoring properties - System.Text.Json.ps1
@@ -1,5 +1,6 @@
-using namespace System.Text.Json
-using namespace System.Collections.Generic
+using namespace System.Collections.Generic
+using namespace System.Text
+using namespace System.Text.Json
 using namespace System.Text.Json.Serialization
 $assembly = Add-type -AssemblyName System.Text.Json -PassThru -ea 'stop'
 goto $PSScriptRoot
@@ -75,10 +76,16 @@ class SimpleProcess {
     [Datetime]$When
 
     # a property that normally errors out (with default serialization)
-    [System.Text.Json.Serialization.JsonIgnoreAttribute()]
+    # or: [System.Text.Json.Serialization.JsonIgnoreAttribute()]
+    [Serialization.JsonIgnoreAttribute()]
     [Diagnostics.ProcessModuleCollection]$Modules
 
     # and a property to only ignore when null
+
+    # [Serialization.JsonIgnoreCondition(
+    #    'always'
+    # )]
+    [JsonIgnoreAttribute( Condition = [JsonIgnoreCondition]::WhenWritingNull) ]
     [object]$MaybeData
 
     SimpleProcess ( ) {
@@ -96,21 +103,28 @@ class SimpleProcess {
     }
 }
 
-[SimpleProcess]@(ps | s -first 1 )
+$pslist = [SimpleProcess[]] @( ps  | s -first 2)
+$psList[0].MaybeData = @{ Name = 'Jen' ; Species = 'cat' }
+
+h1 'should only serialize .MaybeData for one result'
+AutoJson $pslist| jq
 return
-[List[Object]]$Records = @(
+
+[SimpleProcess] @(ps | s -first 1 )
+# return
+[List[Object]] $Records = @(
     # class coerce from an object
-    [SimpleProcess](get-process pwsh | s -First 1)
+    [SimpleProcess] (get-process pwsh | s -First 1)
 
     # explicit ctor
     [SimpleProcess]::new()
 
     # automatic if parameterless c-tor:
-    [SimpleProcess]@{}
+    [SimpleProcess] @{}
 
     # a similar variation
     $One = Get-Process 'pwsh' | Select -first 1
-    [SimpleProcess]$One
+    [SimpleProcess] $One
 )
 
 $records | ft -auto
@@ -119,10 +133,7 @@ $records | ft -auto
 AutoJson $Records
 @'
 [{"Name":null,"CommandLine":"pwsh.exe -nol","When":"2024-01-19T15:13:20.8026851-06:00"},{"Name":null,"CommandLine":null,"When":"2024-01-19T15:13:21.0254829-06:00"},{"Name":null,"CommandLine":"","When":"2024-01-19T15:13:21.0266413-06:00"},{"Name":null,"CommandLine":"pwsh.exe -nol","When":"2024-01-19T15:13:21.0397003-06:00"}]
-'@
-
 
-@'
 If you didn't ignore that property, you'd get an error
 
 Error will occur if 'modules' isn't excluded

diff --git a/Pwsh/Modules/Text.Json/System.Text.Json.CheatSheet.md b/Pwsh/Modules/Text.Json/System.Text.Json.CheatSheet.md
@@ -0,0 +1,46 @@
+- [To Import Namespace](#to-import-namespace)
+- [Serialization](#serialization)
+  - [Ignoring Properties : `JsonIgnoreAttribute`](#ignoring-properties--jsonignoreattribute)
+    - [Ignore When null : `JsonIgnoreCondition`](#ignore-when-null--jsonignorecondition)
+    - [Always Ignore](#always-ignore)
+- [Deserialization](#deserialization)
+
+## To Import Namespace
+
+```ps1
+using namespace System.Collections.Generic
+using namespace System.Text
+using namespace System.Text.Json
+using namespace System.Text.Json.Serialization
+$assembly = Add-type -AssemblyName System.Text.Json -PassThru -ea 'stop'
+```
+
+## Serialization
+
+### Ignoring Properties : `JsonIgnoreAttribute`
+
+#### Ignore When null : `JsonIgnoreCondition`
+
+```ps1
+class SimpleProcess { 
+    [string] $Name
+
+    [JsonIgnoreAttribute( Condition = [JsonIgnoreCondition]::WhenWritingNull) ]
+    [object]$MaybeData
+}
+```
+
+#### Always Ignore
+
+```ps1
+class SimpleProcess { 
+    [string] $Name
+
+    # always skip
+    [Serialization.JsonIgnoreAttribute()]
+    [Diagnostics.ProcessModuleCollection] $Modules
+}
+```
+
+
+## Deserialization
diff --git a/Pwsh/Modules/Text.Json/TinyProc.ps1 b/Pwsh/Modules/Text.Json/TinyProc.ps1
@@ -12,16 +12,16 @@ At least the Linq part
 #>
 
 class TinyProc {
-    [string]$Name
-    [datetime]$When
+    [string]   $Name
+    [datetime] $When
 
     TinyProc () {
         $this.When = Get-date
     }
     TinyProc ( [object]$Other ) {
         $WantedProps = [Linq.Enumerable]::Intersect(
-            [string[]]$This.PSObject.Properties.Name,
-            [string[]]$Other.PSObject.Properties.Name )
+            [string[]] $This.PSObject.Properties.Name,
+            [string[]] $Other.PSObject.Properties.Name )
 
         $This.When = Get-Date
 
@@ -35,9 +35,9 @@ $Ps = get-process pwsh | Select -first 1
 $testCoerce = [TinyProc]$Ps
 
 $records = @(
-    [TinyProc]@{}
+    [TinyProc] @{}
     [TinyProc]::new()
-    [TinyProc]$Ps
+    [TinyProc] $Ps
 )
 $records
 
@@ -48,5 +48,5 @@ variations you could also use:
 @( get-process) -as [TinyProc[]]
     | Out-Null
 
-[TinyProc[]]@(get-process)
+[TinyProc[]] @(get-process)
     | Out-Null