1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
|
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks;
using System.Data.Entity;
namespace Tango.BL.Builders
{
public abstract class EntityBuilderBase<T, TBuilder> : IEntityBuilder<T> where T : ObservableEntity<T> where TBuilder : EntityBuilderBase<T, TBuilder>
{
private List<KeyValuePair<int, Action>> _steps;
private bool _entity_set;
private bool abort_build;
private List<KeyValuePair<int, Func<IQueryable<T>, IQueryable<T>>>> _querySteps;
protected T Entity { get; set; }
protected String EntityGuid { get; set; }
protected ObservablesContext Context { get; set; }
public EntityBuilderBase(ObservablesContext context)
{
_steps = new List<KeyValuePair<int, Action>>();
_querySteps = new List<KeyValuePair<int, Func<IQueryable<T>, IQueryable<T>>>>();
Context = context;
}
public virtual TBuilder Set(Expression<Func<T, bool>> condition)
{
ThrowIfEntitySet();
AddStep(0, () =>
{
abort_build = false;
IQueryable<T> query = Context.Set<T>().Where(condition);
query = OnSetQuery(query);
foreach (var queryStep in _querySteps.ToList().DistinctBy(x => x.Key).OrderBy(x => x.Key))
{
query = queryStep.Value(query);
}
Entity = query.FirstOrDefault();
abort_build = Entity == null;
});
_entity_set = true;
return this as TBuilder;
}
public virtual TBuilder SetFirst()
{
ThrowIfEntitySet();
AddStep(0, () =>
{
abort_build = false;
IQueryable<T> query = Context.Set<T>();
query = OnSetQuery(query);
foreach (var queryStep in _querySteps.ToList().DistinctBy(x => x.Key).OrderBy(x => x.Key))
{
query = queryStep.Value(query);
}
Entity = query.FirstOrDefault();
abort_build = Entity == null;
});
_entity_set = true;
return this as TBuilder;
}
public virtual TBuilder Set(T entity)
{
Entity = entity;
EntityGuid = entity?.Guid;
return Set(entity.Guid);
}
public TBuilder Set(string guid)
{
EntityGuid = guid;
return Set(x => x.Guid == guid);
}
private void ThrowIfEntitySet()
{
if (_entity_set) throw new InvalidOperationException("Could not set entity. Entity was already set.");
}
protected virtual IQueryable<T> OnSetQuery(IQueryable<T> query)
{
return query;
}
protected TBuilder AddStep(int index, Action action)
{
_steps.Add(new KeyValuePair<int, Action>(index, action));
return this as TBuilder;
}
protected TBuilder AddQueryStep(int index, Func<IQueryable<T>, IQueryable<T>> func)
{
_querySteps.Add(new KeyValuePair<int, Func<IQueryable<T>, IQueryable<T>>>(index, func));
return this as TBuilder;
}
protected void CommitSteps()
{
foreach (var step in _steps.ToList().DistinctBy(x => x.Key).OrderBy(x => x.Key))
{
if (!abort_build)
{
step.Value();
_steps.Remove(step);
}
}
}
public virtual T Build()
{
if (!_entity_set)
{
throw new InvalidOperationException("Could not build entity. Entity was not set.");
}
CommitSteps();
return Entity;
}
public Task<T> BuildAsync()
{
return Task.Factory.StartNew<T>(() =>
{
return Build();
});
}
}
}
|
