I am writing a simple XML file parser using LINQ to XML.
I want to have a TreeNode object (i.e a simple Tree structure) for each element in the XML. I want each element to be strongly typed.
It looks ugly and redundant compared to the simple looping approach I was using before (using System.XML). Is there a way to strip out the redundancies here?
XElement ops = XElement.Load(#"c:\temp\exp.xml");
Tree<Element> domain = new Tree<Element>();
domain.Root = new TreeNode<Element>();
var cells =
from cell in ops.Elements("cell")
select new
{
TreeNodeObj = new TreeNode<Element>
(new Cell((string)cell.Attribute("name"), (string)cell.Attribute("name"), null)),
XElem = cell
};
foreach (var cell in cells)
{
domain.Root.AddChild(cell.TreeNodeObj);
var agents =
from agent in cell.XElem.Elements("agent")
select new
{
TreeNodeObj = new TreeNode<Element>
(new Agent((string)agent.Attribute("name"), (string)agent.Attribute("name"), null)),
XElem = agent
};
foreach (var agent in agents)
{
cell.TreeNodeObj.AddChild(agent.TreeNodeObj);
var nas =
from na in agent.XElem.Elements("node-agent")
select new
{
TreeNodeObj = new TreeNode<Element>
(new NodeAgent((string)na.Attribute("name"), (string)na.Attribute("name"), null)),
XElem = agent
};
foreach (var na in nas)
{
agent.TreeNodeObj.AddChild(na.TreeNodeObj);
}
}
}
It is hard to answer this fully without sample data and actual types, but I would refactor it like below.
From the original example, I'm assuming we don't want to mess with the constructors of the entities (Agent etc), and that we want to retain the separate "TreeNode<T>" model, putting our entities inside the tree (rather than changing the entities to model things as associated collections). I've also assumed that we can take more liberties with TreeNode<T> than we can with the entities, so I've introduced a constructor that accepts IEnumerable<...>, since this allows use with LINQ sub-queries:
XElement ops = XElement.Load(#"c:\temp\exp.xml");
Tree<Element> domain = new Tree<Element>(
from cell in ops.Elements("cell")
select new TreeNode<Element>(
new Cell(
(string)cell.Attribute("name"),
(string)cell.Attribute("name"), null
),
from agent in cell.Elements("agent")
select new TreeNode<Element>(
new Agent(
(string)agent.Attribute("name"),
(string)agent.Attribute("name"), null
),
from na in agent.Elements("node-agent")
select new TreeNode<Element>(
new NodeAgent(
(string)na.Attribute("name"),
(string)na.Attribute("name"), null
)
)
)
)
);
With framework code below:
using System.Collections.Generic;
using System.Linq;
using System.Xml.Linq;
class Tree<T>
{
public TreeNode<T> Root { get; set; }
public Tree() { }
public Tree(IEnumerable<TreeNode<T>> children)
{
Root = new TreeNode<T>(children);
}
}
class TreeNode<T>
{
private List<TreeNode<T>> children;
public IList<TreeNode<T>> Children
{
get
{
if (children == null) children = new List<TreeNode<T>>();
return children;
}
}
private readonly T value;
public TreeNode() { }
public TreeNode(T value) { this.value = value; }
public TreeNode(T value, IEnumerable<TreeNode<T>> children)
: this(children)
{
this.value = value;
}
public TreeNode(IEnumerable<TreeNode<T>> children)
{
children = new List<TreeNode<T>>(children);
}
}
class Element { }
class Cell : Element {
public Cell(string x, string y, string z) { }
}
class Agent : Element {
public Agent(string x, string y, string z) { }
}
class NodeAgent : Element {
public NodeAgent(string x, string y, string z) { }
}
static class Program
{
static void Main()
{
XElement ops = XElement.Load(#"c:\temp\exp.xml");
Tree<Element> domain = new Tree<Element>(
from cell in ops.Elements("cell")
select new TreeNode<Element>(
new Cell(
(string)cell.Attribute("name"),
(string)cell.Attribute("name"), null
),
from agent in cell.Elements("agent")
select new TreeNode<Element>(
new Agent(
(string)agent.Attribute("name"),
(string)agent.Attribute("name"), null
),
from na in agent.Elements("node-agent")
select new TreeNode<Element>(
new NodeAgent(
(string)na.Attribute("name"),
(string)na.Attribute("name"), null
)
)
)
)
);
}
}
Without your classes and source xml, it's quite hard to provide you with the exact code you're after, but here's how I like to structure my XML parsing:
XDocument d = XDocument.Parse(#"<a id=""7""><b><c name=""foo""/><c name=""bar""/></b><b/><b2/></a>");
var ae = d.Root;
var a = new A
{
Id = (int)ae.Attribute("id"),
Children = new List<B>(ae.Elements("b").Select(be => new B
{
Children = new List<C>(be.Elements("c").Select(ce => new C
{
Name = (string)ce.Attribute("name")
}))
}))
};
Given the xml:
<a>
<b>
<c name="foo"/>
<c name="bar"/>
</b>
<b/>
<b2/>
</a>
and the classes:
class A
{
public int Id { get; set; }
public List<B> Children { get; set; }
}
class B
{
public List<C> Children { get; set; }
}
class C
{
public string Name { get; set; }
}
Related
I have an array of strings separated by "!". I am trying to break that string up and create a tree hierarchy recursively in my custom class called PivotGroup. For example, what I am aiming at is to break up string array
string[] paths = new string[] {
"ROOT!ZZZ!AAA!EEE!15712",
"ROOT!ZZZ!AAA!EEE!15722",
"ROOT!ZZZ!AAA!EEE!13891"}
Into the PivotGroup class such as PivotGroup contains ChildGroups[] that embed the array strings.
So for example:
PivotGroup pgGroup = new PivotGroup();
pgGroup.ChildGroups[0] = PivotGroup[]; // Key:Book Level 3 Value: "AAA"
Now within Book Level 3 ChildGroups I need to set Book Level 4 which value is "EEE" and within the ChildGroups of "EEE" I would need to create another childGroup array which size in the case would be 3 called Book Level 5 and set another PivotGroup for each of following 15712, 15722, 13891
Here is my PivotGroup Class and embedded class Objects:
public class PivotGroup
{
public PivotGroup() { }
public PivotGroup(PivotGroupKey groupKey, PivotRow data, PivotGroup[] childGroups, bool leaf, int groupLevel)
{
GroupKey = groupKey;
Data = data;
ChildGroups = childGroups;
Leaf = leaf;
GroupLevel = groupLevel;
}
public PivotGroupKey GroupKey { get; private set; }
public PivotRow Data { get; private set; }
public PivotGroup[] ChildGroups { get; set; }
public bool Leaf { get; private set; }
public int GroupLevel { get; private set; }
public override string ToString()
{
return GroupKey + ", GroupLevel: " + GroupLevel + ", Children: " +
ChildGroups.Length + (Leaf ? " (Leaf)" : "");
}
}
public class PivotGroupKey
{
public PivotGroupKey()
{
}
public PivotGroupKey(string keyGroup, string keyValue)
{
if(keyGroup != null)
KeyGroup = string.Intern(keyGroup);
if (keyValue != null)
KeyValue = string.Intern(keyValue);
}
public string KeyGroup { get; private set; }
public string KeyValue { get; private set; }
public override string ToString()
{
return KeyGroup + ": " + KeyValue;
}
}
public class PivotRow
{
public PivotRow()
{
}
public PivotRow(string key, params object[] data) : this(key, true, data) { }
public PivotRow(string key, bool entitled, params object[] data)
{
Data = data;
Key = null;
Entitled = entitled;
}
public object[] Data { get; private set; }
public bool Entitled { get; private set; }
public string Key { get { return null; } set { } }
}
Main program I tried:
public class BookLevels
{
public string Root { get; set; }
public string BookLevel2 { get; set; }
public string BookLevel3 { get; set; }
public string BookLevel4 { get; set; }
public string BookLevel5 { get; set; }
}
class Program
{
static void BuildTree(string[] paths)
{
var BookPaths = paths.Select(x => x.Split('!'))
.Select(x => new BookLevels
{
Root = x[0],
BookLevel2 = x[1],
BookLevel3 = x[2],
BookLevel4 = x[3],
BookLevel5 = x[4]
}).GroupBy(z => new { z.BookLevel3, z.BookLevel4 }).ToArray();
var BookLevel3Cnt = BookPaths.Select(q => q.Key.BookLevel3).Count();
PivotGroup root = new PivotGroup(
new PivotGroupKey("Total", ""),
new PivotRow(null, new string[8]),
new PivotGroup[BookLevel3Cnt], false, 0);
foreach (var booklevel3 in BookPaths)
{
AddChildren(root, booklevel3);
}
}
private static void AddChildren(PivotGroup root, IGrouping<object, BookLevels> booklevel, int index = 0)
{
root.ChildGroups[index] = new PivotGroup(
new PivotGroupKey("Book Level " + (index + 3).ToString(), booklevel.Key.ToString()),
new PivotRow(null, new string[8]),
AddChildren(root, booklevel[index], index + 1), false, 0);
}
static void Main(string[] args)
{
string[] paths = new string[] {
"ROOT!ZZZ!AAA!EEE!15712",
"ROOT!ZZZ!AAA!EEE!15722",
"ROOT!ZZZ!AAA!EEE!13891",
"ROOT!ZZZ!AAA!DDD!15712",
"ROOT!ZZZ!AAA!DDD!15722",
"ROOT!ZZZ!AAA!DDD!13891",
"ROOT!ZZZ!BBB!DDD!15812",
"ROOT!ZZZ!BBB!DDD!15822",
"ROOT!ZZZ!BBB!DDD!13891",
};
BuildTree(paths);
Console.WriteLine();
Console.ReadLine();
}
I think my issue might be the way I am creating the Linq statement that breaks up the string, since I'm not sure how to progress thru it recursively.
I'm not sure what goes into which property. Also, for sake of simplicity and to be able to concentrate on the recursive algorithm, I redefine the group class like this (it does not mean that you have to change your class, instead, adapt my algorithm):
public class PivotGroup
{
public string Key { get; set; }
public List<PivotGroup> ChildGroups { get; } = new List<PivotGroup>();
public override string ToString() => Key; // Makes debugging easier.
}
The idea is that the values of the path go into the key. I made ChildGroups a list to be able to add children successively. My BuildTree returns the root
static PivotGroup BuildTree(string[] paths)
{
var root = new PivotGroup { Key = "ROOT" };
foreach (string path in paths) {
AddChildren(root, path.Split('!').Skip(1).ToList());
}
return root;
}
The recursive part goes into AddChildren. I convert the path into a List<string> to be able to remove the added part. AddChildren assumes that the first item in path is the first child to be added.
static void AddChildren(PivotGroup group, List<string> path)
{
string key = path[0];
int index = group.ChildGroups.FindIndex(g => g.Key == key);
PivotGroup child;
if (index >= 0) { // A child with this key exists.
child = group.ChildGroups[index]; // Select this existing child.
} else { // This key is missing. Add a new child.
child = new PivotGroup { Key = key };
group.ChildGroups.Add(child);
}
if (path.Count > 1) {
path.RemoveAt(0); // Remove the added child key and add the rest recursively.
AddChildren(child, path);
}
}
We add children by walking down the tree and adding new children if necessary.
This prints the tree recursively:
private static void PrintTree(PivotGroup group, int level)
{
Console.WriteLine(new String(' ', 2 * level) + group.Key);
foreach (PivotGroup child in group.ChildGroups) {
PrintTree(child, level + 1);
}
}
string[] paths = new string[] {
"ROOT!ZZZ!AAA!EEE!15712",
...
};
PivotGroup root = BuildTree(paths);
PrintTree(root, 0);
Console.ReadKey();
We could also use a loop instead of doing a recursion, since we add one branch at a time:
static PivotGroup BuildTree(string[] paths)
{
var root = new PivotGroup { Key = "ROOT" };
foreach (string path in paths) {
PivotGroup group = root;
string[] pathElements = path.Split('!');
for (int i = 1; i < pathElements.Length; i++) { // Element [0] is ROOT, we skip it.
string key = pathElements[i];
int index = group.ChildGroups.FindIndex(g => g.Key == key);
PivotGroup child;
if (index >= 0) { // A child with this key exists.
child = group.ChildGroups[index]; // Select this existing child.
} else { // This key is missing. Add a new child.
child = new PivotGroup { Key = key };
group.ChildGroups.Add(child);
}
group = child;
}
}
return root;
}
List<T>.FindIndex is inefficient for large lists. If you have large data sets and the order does not matter, switch to Dictionary<string, PivotGroup>. If you need the data to be sorted, use SortedDictionary<string, PivotGroup>.
Here is some simple recursive code :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string[] paths = new string[] {
"ROOT!ZZZ!AAA!EEE!15712",
"ROOT!ZZZ!AAA!EEE!15722",
"ROOT!ZZZ!AAA!EEE!13891"};
List<List<string>> inputData = paths.Select(x => x.Split(new char[] {'!'}).ToList()).ToList();
Node root = new Node();
Node.ParseTree(root, inputData);
}
}
public class Node
{
public string name { get; set; }
public List<Node> children { get; set; }
public static void ParseTree(Node parent, List<List<string>> inputData)
{
parent.name = inputData.First().FirstOrDefault();
var groups = inputData.Select(x => x.Skip(1)).GroupBy(x => x.Take(1).FirstOrDefault());
foreach (var group in groups)
{
if (group.Key != null)
{
if (parent.children == null) parent.children = new List<Node>();
Node newNode = new Node();
parent.children.Add(newNode);
ParseTree(newNode, group.Select(x => x.Select(y => y).ToList()).ToList());
}
}
}
}
}
I'm using Linq/Lambda to write output to an XML file, just in the standard way:
new XElement("Employees",
from emp in empList
select new XElement("Employee",
new XAttribute("ID", emp.ID),
new XElement("FName", emp.FName),
new XElement("LName", emp.LName),
new XElement("DOB", emp.DOB),
new XElement("Sex", emp.Sex)
));
The issue I'm running into in effect is that my emp class contains fields that don't implement the IEnumerable interface, but which themselves also contain fields (imagine, for example, the emp included a "WorkHistory" field, which itself contained a set of fields related to complaints, commendations, etc). These latter fields are optional (and non-repeating) in the XML schema.
Is there any way of checking whether they have been set (i.e., whether they are null or not) given the Linq/Lambda framework? If they are not set, then the equivalent XML node needs to be absent.
Hope that made sense. I'm new to Linq/Lambda stuff, so sorry if it sounds confused.
I wrote a simple driver. In future, follow this guide when posting.
You can do this several ways. Out of curiosity, I tried out linq:
using System;
using System.Linq;
using System.Xml.Linq;
using System.Collections.Generic;
namespace Rextester
{
public class Program
{
public static void Main(string[] args)
{
var empList = new List<Employee>();
for (int i=0; i<10; i++) {
empList.Add(GenerateTestEmployee(i));
}
var xmlConverter = new XmlConverter();
var employeesNode = new XElement(
"Employees",
empList.Select(emp => xmlConverter.Convert(emp))
);
Console.WriteLine(employeesNode.ToString());
}
private static Employee GenerateTestEmployee(int seed) {
return new Employee() {
ID = Guid.NewGuid(),
FName = seed.ToString(),
LName = "Example",
DOB = DateTime.UtcNow.AddYears(-20).AddYears(-seed),
Sex = seed % 2 == 0 ? "Male" : "Female",
WorkHistory = GenerateTestWorkHistory(seed)
};
}
private static WorkHistory GenerateTestWorkHistory(int seed) {
if (seed % 7 == 0) {
return null;
}
return new WorkHistory() {
Complaints = Enumerable.Repeat("Complaint!", seed % 2).ToList(),
Commendations = Enumerable.Repeat("Commendation!", seed % 3).ToList()
};
}
}
public class Employee {
public Guid ID { get; set; }
public string FName { get; set; }
public string LName { get; set; }
public DateTime DOB { get; set; }
public string Sex { get; set; }
public WorkHistory WorkHistory { get; set; }
}
public class WorkHistory {
public List<string> Complaints { get; set; }
public List<string> Commendations { get; set; }
}
public class XmlConverter {
public XElement Convert(Employee emp) {
var attributes = new List<XAttribute> {
new XAttribute("ID", emp.ID)
};
var elements = new List<XElement> {
new XElement("FName", emp.FName),
new XElement("LName", emp.LName),
new XElement("DOB", emp.DOB),
new XElement("Sex", emp.Sex)
};
var workHistory = Convert(emp.WorkHistory);
if (workHistory != null) {
elements.Add(workHistory);
}
return new XElement("Employee", attributes, elements);
}
private XElement Convert(WorkHistory hist) {
if (hist == null) {
return null;
}
var elements = new List<XElement>();
if (hist.Complaints != null && hist.Complaints.Any()) {
var complaints = new XElement(
"Complaints",
hist.Complaints.Select(comp => new XElement("Complaint", comp))
);
elements.Add(complaints);
}
if (hist.Commendations != null && hist.Commendations.Any()) {
var commendations = new XElement(
"Commendations",
hist.Commendations.Select(comm => new XElement("Commendation",comm))
);
elements.Add(commendations);
}
return elements.Any() ? new XElement("WorkHistory", elements)
: null;
}
}
}
Good luck!
PS: I find this online IDE helpful for testing snippets.
Using method syntax, as opposed to query syntax, you can build Employee element gradually, adding optional child elements only when it should :
new XElement("Employees",
empList.Select(emp => {
var xe = new XElement("Employee",
new XAttribute("ID", emp.ID),
....
));
// do further checks and add optional child elements accordingly
if (emp.WorkHistory != null) xe.Add(new XElement(...));
// return the final result
return xe;
})
)
Objective: process an object and if the object implements an expected type, I want to change a specific property value (this part is working fine), and I also would like to apply the same logic to all property lists (that I explicit point) that are of the same expected type.
I have the following code:
public abstract class BaseObject
{
public int Id { get; set; }
}
public class Father : BaseObject
{
public DateTime CreatedOn { get; set; }
public string Name { get; set; }
public IEnumerable<ChildA> Children1 { get; set; }
public IEnumerable<ChildB> Children2 { get; set; }
public IEnumerable<ChildA> Children3 { get; set; }
public IEnumerable<ChildB> Children4 { get; set; }
}
public class ChildA : BaseObject
{
public int Val1 { get; set; }
}
public class ChildB : BaseObject
{
public string Name { get; set; }
public int Total { get; set; }
}
I want to process an object by applying some changes on a specific property on the target object and on all property children that I explicit say:
public void Start()
{
var listA = new List<ChildA> { new ChildA { Id = 1, Val1 = 1 }, new ChildA { Id = 2, Val1 = 2 } };
var listB = new List<ChildB> { new ChildB { Id = 1, Name = "1", Total = 1 } };
var obj = new Father { Id = 1, CreatedOn = DateTime.Now, Name = "F1", ChildrenA = listA, ChildrenB = listB };
// I explicit tell to process only 2 of the 4 lists....
ProcessObj(obj, x => new object[] { x.Children1, x.Children2 });
}
I was able to write this function:
public void ProcessObj<T>(T obj, Expression<Func<T, object[]>> includes = null)
{
var objBaseObject = obj as BaseObject;
if (objBaseObject == null) return;
// Here I change the ID - add 100 just as an example....
objBaseObject.Id = objBaseObject.Id + 100;
if (includes == null) return;
var array = includes.Body as NewArrayExpression;
if (array == null) return;
var exps = ((IEnumerable<object>)array.Expressions).ToArray();
for (var i = 0; i < exps.Count(); i++)
{
var name = ((MemberExpression)exps[i]).Member.Name;
var childProperty = obj.GetType().GetProperties(
BindingFlags.Public | BindingFlags.Instance
).FirstOrDefault(prop => prop.Name == name);
if (childProperty == null) continue;
// NOT correct because I think I am getting a copy of the object
// and not pointing to the object in memory (by reference)
var childList = childProperty.GetValue(obj);
// TODO: loop on the list and apply the same logic as the father....
// change the ID field....
}
}
In this prototype I started writing reflection, but I really would like to avoid it if possible....
How can I do this???
Maybe I'm missing something, but it seems like you're complicating the problem by using expression trees. Can you just not use a regular Action and Func delegates to do this? Why do they need to be expression trees? Here's an example just using delegates:
public void ProcessObj<T>(T obj, Func<T, IEnumerable<object>> includes) {
var objBaseObject = obj as BaseObject;
if (objBaseObject == null) return;
// Create a reusable action to use on both the parent and the children
Action<BaseObject> action = x => x.Id += 100;
// Run the action against the root object
action(objBaseObject);
// Get the includes by just invoking the delegate. No need for trees.
var includes = includes(obj);
// Loop over each item in each collection. If the types then invoke the same action that we used on the root.
foreach(IEnumerable<object> include in includes)
{
foreach(object item in include)
{
var childBaseObject = item as BaseObject;
if(childBaseObject != null)
{
action(childBaseObject);
}
}
}
}
Useable just like before:
ProcessObj(obj, x => new object[] { x.Children1, x.Children2 });
No expression trees and no reflection, just regular delegate lambdas.
Hope that helps
I have the domain classes separated from the ones I use in the views, so when retrieving data I have to map the domain classes to the view ones.
Until now this have been straight forward, but now I have a case in which I need to map parent-child classes from the domain to parent-child classes on the view.
Using foreach structures works fine, but I have quite a few linq methods that do the mapping between domain and view classes, that need to be refactored to accomodated to the new requirements and would be faster if I knew how to do it with linq. Thanks in advance.
As an example of what I'm trying to accomplish see code below:
In the repository I have the classes:
public class Parent
{
public int ParentId { get; set; }
public string ParentName { get; set; }
};
public class ChildA : Parent
{
public string ChildPropertyA { get; set; }
};
public class ChildB : Parent
{
public string ChildPropertyB { get; set; }
};
Then in the UI I have the classes:
public class ParentVM
{
public int ParentIdVM { get; set; }
public string ParentNameVM { get; set; }
};
public class ChildAVM : ParentVM
{
public string ChildPropertyAVM { get; set; }
};
public class ChildBVM : ParentVM
{
public string ChildPropertyBVM { get; set; }
};
Now I will have a service class in which the methods will look like the one below:
public GetParentVMs()
{
var parents = initializeRepositoryClass();
var parentsVM = MapRepositoryToViewClasses(parents);
ShowResult(parentsVM);
}
Where:
public List<Parent> initializeRepositoryClass()
{
var parents = new List<Parent>(){
new ChildA(){ParentId=1, ParentName="Parent 1", ChildPropertyA="A"},
new Parent(){ParentId=2, ParentName="Parent 2"},
new ChildB(){ParentId=3, ParentName="Parent 3", ChildPropertyB="B"},
};
return parents;
}
private List<ParentVM> MapRepositoryToViewClasses(List<Parent> parents)
{
var parentsVM = new List<ParentVM>();
foreach (var item in parents)
{
if (item is ChildA)
{
var itemVM = item as ChildA;
parentsVM.Add(
new ChildAVM() { ParentIdVM = itemVM.ParentId, ParentNameVM = itemVM.ParentName, ChildPropertyAVM = itemVM.ChildPropertyA }
);
}
else if (item is ChildB)
{
var itemVM = item as ChildB;
parentsVM.Add(
new ChildBVM() { ParentIdVM = itemVM.ParentId, ParentNameVM = itemVM.ParentName, ChildPropertyBVM = itemVM.ChildPropertyB }
);
}
else
{
var itemVM = item as Parent;
parentsVM.Add(
new ParentVM() { ParentIdVM = itemVM.ParentId, ParentNameVM = itemVM.ParentName }
);
}
}
return parentsVM;
}
private void ShowResult(List<ParentVM> parentsVM)
{
foreach (var item in parentsVM)
{
if (item is ChildAVM)
{
var ca = (ChildAVM)item;
Console.WriteLine("Child A " + ca.ChildPropertyAVM);
}
else if (item is ChildBVM)
{
var cb = (ChildBVM)item;
Console.WriteLine("Child B " + cb.ChildPropertyBVM);
}
else
{
Console.WriteLine("Parent ");
}
}
}
The code above will work, but I like to change the method MapRepositoryToViewClasses to another that uses linq, and looks a like the one below:
private List<ParentVM> MapRepositoryToViewClassesLinq(List<Parent> parents)
{
var parentsVM =
from p in parents
case
p is ChildA then select new ChildAVM() {ChildPropertyAVM = p.ChildPropertyA, ...};
else
p is ChildB then select new ChildBVM() {ChildPropertyBVM = p.ChildPropertyB, ...};
else
select new ParentVM() {ParentIdVM = p.ParentId};
return parentsVM.ToList();
}
Any ideas? Thanks.
You need some changes in your code to make it better
1) You have to introduce a factory to create VM's instances.
class VMFactory
{
public ParentVM Create(Parent obj)
{
var childA = obj as ChildA;
if (childA != null)
{
return new ChildAVM() { ParentIdVM = childA.ParentId, ParentNameVM = childA.ParentName, ChildPropertyAVM = childA .ChildPropertyA };
}
var childB = obj as ChildB;
if(childB != null)
{
return new ChildBVM() { ParentIdVM = childB.ParentId, ParentNameVM = childB.ParentName, ChildPropertyBVM = childB.ChildPropertyB };
}
return new ParentVM() { ParentIdVM = obj.ParentId, ParentNameVM = obj.ParentName };
}
}
2) Now you can simplify your code at MapRepositoryToViewClasses method
private List<ParentVM> MapRepositoryToViewClasses(List<Parent> parents)
{
// Factory instance can be provided by the outer scope
var factory = new VMFactory();
var parentsVM = new List<ParentVM>();
foreach (var item in parents)
{
parentsVM.Add(factory.Create(item));
}
return parentsVM;
}
3) Final step, let's use Linq to map
private List<ParentVM> MapRepositoryToViewClasses(List<Parent> parents)
{
// Factory instance can be provided by the outer scope
var factory = new VMFactory();
return parents.Select(factory.Create).ToList();
}
It's done
Yet another attempt to solve it
1) Create the extensions to solve common tasks.
static class Ext
{
public static ParentVM Map<TIn>(this TIn obj, Func<TIn, ParentVM> func)
where TIn : Parent
{
var source = obj as TIn;
return source != null
? func(obj)
: null;
}
}
2) Use the extension method to get VMs
private List<ParentVM> MapRepositoryToViewClassesLinq(List<Parent> parents)
{
var tmp = from p in parents
select
p.Map<ChildA>(c => new ChildAVM() { ParentIdVM = c.ParentId, ParentNameVM = c.ParentName, ChildPropertyAVM = c.ChildPropertyA }) ??
p.Map<ChildB>(c => new ChildBVM() { ParentIdVM = c.ParentId, ParentNameVM = c.ParentName, ChildPropertyBVM = c.ChildPropertyB }) ??
new ParentVM() { ParentIdVM = obj.ParentId, ParentNameVM = obj.ParentName };
return tmp.ToList();
}
If you setup mapping extensions for each type, then the mapping process becomes trivial.
SQL Fiddle: https://dotnetfiddle.net/a4eQ6S
How to map (GetParentsVM())
var parents = initializeRepositoryClass();
var parentsVM = parents.Map();
Mapping Extensions
public static class ParentMappings
{
public static ChildAVM Map(this ChildA model)
{
return new ChildAVM()
{
ParentIdVM = model.ParentId,
ParentNameVM = model.ParentName,
ChildPropertyAVM = model.ChildPropertyA,
};
}
public static ChildBVM Map(this ChildB model)
{
return new ChildBVM()
{
ParentIdVM = model.ParentId,
ParentNameVM = model.ParentName,
ChildPropertyBVM = model.ChildPropertyB,
};
}
public static ParentVM Map(this Parent model)
{
if (model is ChildA)
return ((ChildA)model).Map();
else if (model is ChildB)
return ((ChildB)model).Map();
else
return new ParentVM()
{
ParentIdVM = model.ParentId,
ParentNameVM = model.ParentName,
};
}
public static List<ParentVM> Map(this List<Parent> parents)
{
return parents.Select(p => p.Map()).ToList();
}
}
First, I did check this post but it is in Python, first, and second it appears to be actually making the directories, which I cannot do in this scenario.
Second, these are not directories that exist, nor can I create them.
I have an input in C# like this:
List<string> filePaths = new List<string>();
filePaths.Add(#"ProgramDir\InstallDir\Module1\mod1pack1.exe");
filePaths.Add(#"ProgramDir\InstallDir\Module1\mod1pack2.exe");
filePaths.Add(#"ProgramDir\InstallDir\Module2\mod2pack1.exe");
filePaths.Add(#"ProgramDir\InstallDir\Module1\SubModule1\report1.rpt");
filePaths.Add(#"SystemDir\DependencyDir\dependency1.dll");
filePaths.Add(#"SystemDir\DependencyDir\dependency2.dll");
What I have been trying to do is create an object that represents this structure, such that it could be visualized like this:
-ProgramDir
Installdir
Module1
mod1pack1.exe
mod1pack2.exe
-SubModule1
report1.rpt
Module2
mod2pack1.exe
-SystemDir
-DependencyDir
dependency1.dll
dependency2.dll
What I have tried is various versions of the following, and I could really use some help to figure out where I've got it wrong.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
SetFilePathList();
DTree forest = new DTree();
List<DTreeBranch> branches = new List<DTreeBranch>();
foreach (string path in filePaths)
{
forest.GrowTree(path.Split('\\'), branches);
}
forest.SubBranches.AddRange(branches);
}
private static List<string> filePaths { get; set; }
private static void SetFilePathList()
{
filePaths = new List<string>();
filePaths.Add(#"ProgramDir\InstallDir\Module1\mod1pack1.exe");
filePaths.Add(#"ProgramDir\InstallDir\Module1\mod1pack2.exe");
filePaths.Add(#"ProgramDir\InstallDir\Module2\mod2pack1.exe");
filePaths.Add(#"ProgramDir\InstallDir\Module1\SubModule1\report1.rpt");
filePaths.Add(#"SystemDir\DependencyDir\dependency1.dll");
filePaths.Add(#"SystemDir\DependencyDir\dependency2.dll");
}
}
public class DTree
{
public List<DTreeBranch> SubBranches { get; set; }
public string BranchName { get; set; }
public DTree() { SubBranches = new List<DTreeBranch>(); }
public DTreeBranch AddChildren(string[] childElements, DTreeBranch branch)
{
DTreeBranch childBranch;
foreach (string element in childElements)
{
childBranch = new DTreeBranch();
childBranch.BranchName = element;
branch.SubBranches.Add(childBranch);
var query = from q in childElements
where q != childBranch.BranchName
select q;
AddChildren(query.ToArray<string>(), childBranch);
}
return branch;
}
public void GrowTree(string[] pathElements, List<DTreeBranch> Branches)
{
DTreeBranch result = Branches.Find(delegate(DTreeBranch b)
{
return b.BranchName == pathElements[0];
});
if (result == null)
{
DTreeBranch newRootBranch = new DTreeBranch();
newRootBranch.BranchName = pathElements[0];
Branches.Add(newRootBranch);
GrowTree(pathElements, Branches);
}
else
{
var query = from q in pathElements
where q != result.BranchName
select q;
DTreeBranch childBranch = AddChildren(query.ToArray<string>(), result);
Branches.Add(childBranch);
}
}
}
public class DTreeBranch
{
public List<DTreeBranch> SubBranches { get; set; }
public string BranchName { get; set; }
public DTreeBranch()
{
SubBranches = new List<DTreeBranch>();
}
}
}
The main thing is that the output is only two layers deep. I guess what I'm saying is that the new elements are added to the depth, not the breadth, and I'm at a loss as to how to effectively work through this. I also think that I have way more code than I need.
Thanks in advance.
I'm not sure exactly what our goals are, but a simple recursive parse will do it quite easily. Wrote this up, and hope it helps. You can make it significantly more fancy if you want, with DTrees and sub branches, or separate collections for Files and Directories, etc. I don't really understand what all that code in there is for. If it has something to do with WIX, I'm sorry ;) And you could always use something like this to parse it out into the tree, and then convert that sanely to a different format.
this assumes no duplicate leaf nodes (file names).
if that isn't the case, just add a sanity check like for directories.
The main "Node" class -
public class Node
{
public string Name { get; set; }
public bool IsDirectory { get; set; }
public List<Node> Children = new List<Node>();
internal void AddChildren(string f)
{
var dirs = Path.GetDirectoryName(f);
if (string.IsNullOrEmpty(dirs))
{
// we are adding a file
var file = Path.GetFileName(f);
Children.Add(new Node {Name = file, IsDirectory = false});
}
else
{
// we are adding a directory
var firstDir = dirs.Split(Path.DirectorySeparatorChar)[0];
var childNode = Children.FirstOrDefault(d => d.Name == firstDir);
if (childNode == null)
{
childNode = new Node {Name = firstDir, IsDirectory = true};
Children.Add(childNode);
}
var subPath = f.Substring(firstDir.Length + 1);
childNode.AddChildren(subPath);
}
}
}
Calling it is simple, like this:
var filePaths = new List<string> {
#"ProgramDir\InstallDir\Module1\mod1pack1.exe",
#"ProgramDir\InstallDir\Module1\mod1pack2.exe",
#"ProgramDir\InstallDir\Module2\mod2pack1.exe",
#"ProgramDir\InstallDir\Module1\SubModule1\report1.rpt",
#"SystemDir\DependencyDir\dependency1.dll",
#"SystemDir\DependencyDir\dependency2.dll",
};
var node = new Node { Name = "Root", IsDirectory = true };
foreach (var f in filePaths )
{
node.AddChildren(f);
}
Printing it out (with indent per level, gives me this)
public static void PrintNode(Node node, int indent)
{
if (indent > 0) // don't print out root directory (level 1).
{
var ending = node.IsDirectory ? Path.DirectorySeparatorChar.ToString() : "*";
Console.WriteLine("{0}{1}{2}", new string('\t', indent - 1), node.Name, ending);
}
node.Children.ForEach(n => PrintNode(n, indent + 1));
}
ProgramDir\
InstallDir\
Module1\
mod1pack1.exe*
mod1pack2.exe*
SubModule1\
report1.rpt*
Module2\
mod2pack1.exe*
SystemDir\
DependencyDir\
dependency1.dll*
dependency2.dll*
I got about the same as Andrew:
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
namespace ConsoleApplication1
{
class Program
{
public static void Main(String[] args)
{
var filePaths = new List<string> {#"ProgramDir\InstallDir\Module1\mod1pack1.exe", #"ProgramDir\InstallDir\Module1\mod1pack2.exe", #"ProgramDir\InstallDir\Module2\mod2pack1.exe", #"ProgramDir\InstallDir\Module1\SubModule1\report1.rpt", #"SystemDir\DependencyDir\dependency1.dll", #"SystemDir\DependencyDir\dependency2.dll"};
var nodes = Parse(filePaths.ToArray());
foreach (var node in nodes)
Console.Out.WriteLine(node.ToString());
Console.ReadLine();
}
public static IEnumerable<Node> Parse(params String[] paths)
{
var roots = new NodeSet();
foreach (var path in paths)
{
var pathSplit = path.Split('\\');
Node current = null;
foreach (var pathElement in pathSplit)
{
var currentRoots = (current == null) ? roots : current.Children;
if (currentRoots.Contains(pathElement))
current = currentRoots[pathElement];
else
currentRoots.Add(current = new Node(pathElement));
}
}
return roots;
}
public class Node
{
public String Name { get; private set; }
public NodeSet Children { get; private set; }
public Node(String name)
{
if (String.IsNullOrWhiteSpace(name)) throw new ArgumentNullException("name");
Name = name;
Children = new NodeSet();
}
public override string ToString() { return ToString(1); }
private String ToString(Int32 indent)
{
var indentStr = Environment.NewLine + new string('\t', indent);
return Name + (Children.Count == 0 ? "" : indentStr + String.Join(indentStr, Children.Select(c => c.ToString(indent + 1)).ToArray()));
}
}
public class NodeSet : KeyedCollection<String, Node> {
protected override string GetKeyForItem(Node item) { return item.Name; }
}
}
}