Geek asks and answers

Using lambda inside a method and matching with a list

I have the following code that is used to create data for a jquery graph. However, it is quite repetitive and in order to preserve DRY, I would like to reorganize by introducing a method.

sb.Append("{name: 'Pull Ups', data: [");
foreach(var item in data)
{
    sb.Append(prefix); prefix = ",";
    sb.Append(item.PullUps);
}
sb.Append("]}");

sb.Append("{name: 'Push Ups', data: [");
prefix = string.Empty;
foreach (var item in data)
{
    sb.Append(prefix);  prefix = ",";
    sb.Append(item.PushUps);
}
sb.Append("]}");

I need a method similar to

void Data(ref StringBuilder sb, string title, IList<DataDto> data,  ...)

And I would like my code to be something like: -

Data(ref sb, "Pull Ups", data, d=>d.PullUps);
Data(ref sb, "Push Ups", data, d=>d.PushUps);
Data(ref sb, "Squats", data, d=>d.Squats);

However, I am struggling to figure out how to do this. I know that I need to use something similar line by line

private static void Data<T, TProp>(ref StringBuilder sb, 
   IList<T> data, Func<T, TProp> selector)

and inside (pusedocode)

foreach(var item in data) {
  if (selector == ???)
   sb.Append(??);
}

My DataDto is pretty simple: -

public class DataDto
{
    public virtual decimal PullUps { get;  set; }
    public virtual decimal PushUps { get;  set; }
    public virtual decimal Squats { get;  set; }
 ...
}
+3
source share
2 answers

I think you want something like this:

void YourMethod<TItem, TProp>(StringBuilder sb, string name, IList<TItem> data,
                              Func<TItem, TProp> selector)
{
    var prefix = "";
    sb.Append("{name: '"+name+"', data: [");
    foreach(var item in data)
    {
        sb.Append(prefix);
        prefix = ",";
        sb.Append(selector(item).ToString());
    }
    sb.Append("]}");
}

You would call it this way:

YourMethod(sb, "Pull Ups", data, d=>d.PullUps);
YourMethod(sb, "Push Ups", data, d=>d.PushUps);
YourMethod(sb, "Squats", data, d=>d.Squats);
+3
source

How about simplifying the code?

sb.Append("{name: 'Pull Ups', data: [");
sb.Append(String.Join(",", myExercises.Select(e=>e.PullUps));}
sb.Append("]}");

sb.Append("{name: 'Push Ups', data: [");
sb.Append(String.Join(",", myExercises.Select(e=>e.PushUps));}
sb.Append("]}");

, , ? ?

+2

More articles:


All Articles