B4J Library [B4X] [Web] MinimaListUtils

MinimaListUtils
Version : 1.07
A utility class to manipulate a simple List of Map to do basic CRUD.

Treat it as some kind of a NoSQL for key-value pairs.
It is suitable for small demo if you don't want to use SQL database.

It depends on KeyValueStore library.
Note: You can remove this dependency and use File.WriteBytes and File.ReadBytes.

This b4xlib replaces the class from MinimaList formerly published in B4J code snippet.

Code snippets also included for creating RESTful API subs for MinimaList Controller when developing with Web API Template 2.04+.

Properties

• First As Map (read/write)
• Last As Map (read/write)
• List (read/write)

Methods

• Add (M As Map)
• Clone As MinimaList
• CopyList As Object
• CopyObject (xo As Object) As Object
• Count (key As String, id As Long) As Int
• Exclude (id As Long) As List
• ExcludeAll (keys As List, values As List) As List
• ExcludeAny (keys As List, values As List) As List
• Find (id As Long) As Map
• FindAll (keys As List, values As List) As List
• FindAnyLike (keys As List, values As List) As List
• FindByKey (key As String, value As Object)
• FindFirst (keys As List, values As List) As Map
• IndexFromId (id As Long) As Long
• IndexFromMap (M As Map) As Long
• Limit (Number As Int) As MinimaList
• Remove (index As Long)
• Remove2 (M As Map)
• RemoveKey (key As String, index As Long)
• RemoveKey2 (key As String, M As Map)
• Reverse As MinimaList
• SortByKey (key As String, ascending As Boolean)
• SortByKey2 (key As String, ascending As Boolean, default As Object)

What's New

• Version 1.07
  • Added Limit
  • Replace dependency of KeyValueStore to RandomAccessFile
• Version 1.06
  • Added Clone
  • Update Reverse return the resulted object
  • Update SortByKey
  • Added SortByKey2
  • First and Last properties are now writable
• Version 1.05
  • Fix bug in SortByKey
  • Added CopyObject
  • Update CopyList
• Version 1.04
  • Added Reverse, FindByKey, SortByKey
  • Updated Snippet 08
• Version 1.03
  • Update Snippets, removed #plural tag
• Version 1.02
  • Added CopyList sub
• Version 1.01
  • Add KeyValueStore dependency to manifest file

GitHub: https://github.com/pyhoon/MinimaListUtils-B4X

 

[aeric]

• Version 1.01
  • Add KeyValueStore dependency to manifest file.

 

[aeric]

• Version 1.02
  • Added CopyList sub

 

[AlenaFranskin]

Thank you for the shared version.

Fun Games​

 

[aeric]

• Version 1.03
  • Update Snippets, removed #plural tag

 

[aeric]

• Version 1.04
  • Added Reverse, FindByKey, SortByKey
  • Updated Snippet 08

 

[aeric]

• Version 1.05
  • Fix bug in SortByKey
  • Added CopyObject
  • Update CopyList

 

[aeric]

Base on the example using Type Variable in this post: https://www.b4x.com/android/forum/threads/need-help-with-structures.163479/#post-1002764

Sub Example
    Dim Persons As MinimaList
    Persons.Initialize
    Dim missing As Int = -1
    Dim names() As String = Array As String("John", "Alice", "Anne", "Michael", "Gordon", "William")
    For Each name As String In names
        Dim age As Int = Rnd(18, 90)
        If age Mod 2 = 0 Then age = missing
        Dim person As Map = CreatePerson(1, name, "", "", age)
        Persons.Add(person)
    Next
    
    Log($"id${TAB}Name${TAB}Age${TAB}Group"$)
    For Each p As Map In Persons.List
        Log(p.Get("id") & TAB & p.Get("Name") & TAB & IIf(missing = p.Get("Age"), "-", p.Get("Age")) & TAB & p.Get("Group"))
    Next
    
    ' Update value
    Persons.FindByKey("Name", "Anne").Put("Age", 22)
    
    ' Sort by key
    Persons.SortByKey("Age", True)
    
    Log(TAB)
    Log($"id${TAB}Name${TAB}Age${TAB}Group"$)
    For Each p As Map In Persons.List
        Log(p.Get("id") & TAB & p.Get("Name") & TAB & IIf(missing = p.Get("Age"), "-", p.Get("Age")) & TAB & p.Get("Group"))
    Next
End Sub

Sub CreatePerson (Group As Int, Name As String, Address As String, City As String, Age As Int) As Map
    Return CreateMap("Group": Group, "Name": Name, "Address": Address, "City": City, "Age": Age)
End Sub

id   Name     Age    Group
1    John     77     1
2    Alice    -      1
3    Anne     33     1
4    Michael  -      1
5    Gordon   -      1
6    William  57     1
    
id   Name     Age    Group
2    Alice    -      1
4    Michael  -      1
5    Gordon   -      1
3    Anne     22     1
6    William  57     1
1    John     77     1

 

[aeric]

• Version 1.06
  • Added Clone
  • Update Reverse return the resulted object
  • Update SortByKey
  • Added SortByKey2
  • First and Last properties are now writable

Based on example on post #8 above

' Sort by key
Persons.SortByKey("Age", True)

' Put default value if key does not exist
Persons.SortByKey2("Age", True, -1)

Log(Persons.Reverse.List)

Log(Persons.Last)
Dim Clone1 As MinimaList = Persons.Clone
Log(Clone1.Last)

Log(Clone1.Reverse)
Log(Clone1.Last)

Log(Persons.Last) ' original MinimaList has not affected

 

[aeric]

It depends on KeyValueStore library.
Note: You can remove this dependency and use File.WriteBytes and File.ReadBytes.

I think it is possible. I haven't tested it.
I added the dependency so it is automatically available to use in MinimaList/Web Api template.

Basically there are 2 methods in the library that depends on jRandomAccessFile or equivalent in other platforms.
Edit: Methods SortByKey, SortByKey2 and Clone also depends on these 2 methods.

' Make a copy of the List
Public Sub CopyList As List
    Dim ser As B4XSerializator
    Return ser.ConvertBytesToObject(ser.ConvertObjectToBytes(mList))
End Sub

' Make a copy of an Object/Map
Public Sub CopyObject (xo As Object) As Object
    Dim ser As B4XSerializator
    Return ser.ConvertBytesToObject(ser.ConvertObjectToBytes(xo))
End Sub

Why we want to avoid using KeyValueStore library?
Because this library is dependent on SQL library.
If you want to make a smaller project then you may want to consider this question.

 

[aeric]

I think it is possible. I haven't tested it.
I added the dependency so it is automatically available to use in MinimaList/Web Api template.

Basically there are 2 methods in the library that depends on jRandomAccessFile or equivalent in other platforms.
Edit: Methods SortByKey, SortByKey2 and Clone also depends on these 2 methods.

' Make a copy of the List
Public Sub CopyList As List
    Dim ser As B4XSerializator
    Return ser.ConvertBytesToObject(ser.ConvertObjectToBytes(mList))
End Sub

' Make a copy of an Object/Map
Public Sub CopyObject (xo As Object) As Object
    Dim ser As B4XSerializator
    Return ser.ConvertBytesToObject(ser.ConvertObjectToBytes(xo))
End Sub

Why we want to avoid using KeyValueStore library?
Because this library is dependent on SQL library.
If you want to make a smaller project then you may want to consider this question.

I have tested.
Just replace KeyValueStore library with RandomAccessFile library.

A simple app compiled with the following:
KeyValueStore: 3250 KB
RandomAccessFile: 140 KB (reduced 95% of size or 3110 KB)

Dim Clone1 As MinimaList = Persons.Clone
Dim data As Map = CreateMap("persons": Clone1.List)
Dim ser As B4XSerializator
File.WriteBytes(File.DirApp, "data", ser.ConvertObjectToBytes(data))

Dim data As Map = ser.ConvertBytesToObject(File.ReadBytes(File.DirApp, "data"))
Dim persons As MinimaList
persons.Initialize
persons.List = data.Get("persons")
Log(persons.FindByKey("name", "aeric"))

 

[aeric]

Version 1.07

• Added Limit
• Replace dependency of KeyValueStore to RandomAccessFile