# 以 HTMX 和 ASP.NET 核心 {-}*Part * 4:}建立工作流程系统

<!--category-- ASP.NET, Hangfire, Workflow, Background Jobs -->
<datetime class="hidden">2025-01-15T18:00</datetime>

## 一. 导言导言 导言 导言 导言

内 [部分#3](/blog/workflowsystem-part3-visual-editor)@,_#我们建造了一个美丽的视觉编辑@.}但是我们的工作流程只有在我们手动触发它们的时候才能运行 在最后的一篇文章“,\% we'}使用Hangfire 来“MS K5”使工作流程真正自主

- **计划执行** - 运行工作流程在日程上
- **AIP 投票** - 监控外部API和触发更改
- **国家管理** 跨处决的轨道触发状态
- **仪表板** - 监视所有背景工作

[TOC]

## 为何要上火?

着火是最适合我们需要的,因为它能满足我们的需要。

- 我们现有PostgreSQL数据库的仓库工作
- 提供已建的“-”仪表板
- 支持经常性工作
- 具有自动重试逻辑
- 水平水平缩平

## 触发国模式

第一次,#让我们来理解我们的触发国实体 @(}我们已经在Part Z2):_BARBAR_

```csharp
[Table("workflow_trigger_states")]
public class WorkflowTriggerStateEntity
{
    public int Id { get; set; }
    public int WorkflowDefinitionId { get; set; }

    // Type: "Schedule", "ApiPoll", "Webhook"
    public string TriggerType { get; set; } = string.Empty;

    // Configuration as JSON
    public string ConfigJson { get; set; } = "{}";

    // Current state as JSON (stores last poll time, content hash, etc.)
    public string StateJson { get; set; } = "{}";

    public bool IsEnabled { get; set; } = true;
    public DateTime? LastCheckedAt { get; set; }
    public DateTime? LastFiredAt { get; set; }
    public int FireCount { get; set; } = 0;
    public string? LastError { get; set; }
}
```

此实体跟踪所有关于工作流程触发@: @%

- 当它最后一次运行时
- 其配置是什么
- 在“(”中,用于指定触发器“MS K2”的状态如何?
- 发生的任何错误

## 工作流量

### 配置模型

```csharp
public class ScheduleTriggerConfig
{
    public string IntervalType { get; set; } = "minutes"; // minutes, hours, days
    public int IntervalValue { get; set; } = 60;
    public Dictionary<string, object>? InputData { get; set; }
}
```

### 调度工作

```csharp
public class WorkflowSchedulerJob
{
    private readonly MostlylucidDbContext _context;
    private readonly WorkflowExecutionService _executionService;
    private readonly ILogger<WorkflowSchedulerJob> _logger;

    [AutomaticRetry(Attempts = 3)]
    public async Task ExecuteScheduledWorkflowsAsync()
    {
        _logger.LogInformation("Checking for scheduled workflows");

        // Get all enabled schedule triggers
        var triggers = await _context.WorkflowTriggerStates
            .Include(t => t.WorkflowDefinition)
            .Where(t => t.IsEnabled && t.TriggerType == "Schedule")
            .ToListAsync();

        foreach (var trigger in triggers)
        {
            try
            {
                var config = JsonSerializer.Deserialize<ScheduleTriggerConfig>(
                    trigger.ConfigJson);

                if (config == null) continue;

                // Check if it's time to run
                if (!ShouldRunScheduledWorkflow(trigger, config))
                    continue;

                _logger.LogInformation(
                    "Executing scheduled workflow {WorkflowId}",
                    trigger.WorkflowDefinition.WorkflowId);

                // Execute the workflow
                await _executionService.ExecuteWorkflowAsync(
                    trigger.WorkflowDefinition.WorkflowId,
                    config.InputData,
                    "Scheduler");

                // Update trigger state
                trigger.LastCheckedAt = DateTime.UtcNow;
                trigger.LastFiredAt = DateTime.UtcNow;
                trigger.FireCount++;

                var state = JsonSerializer.Deserialize<Dictionary<string, object>>(
                                trigger.StateJson) ?? new();
                state["lastRun"] = DateTime.UtcNow.ToString("O");
                trigger.StateJson = JsonSerializer.Serialize(state);

                await _context.SaveChangesAsync();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex,
                    "Error executing scheduled workflow {TriggerId}",
                    trigger.Id);
                trigger.LastError = ex.Message;
                await _context.SaveChangesAsync();
            }
        }
    }

    private bool ShouldRunScheduledWorkflow(
        WorkflowTriggerStateEntity trigger,
        ScheduleTriggerConfig config)
    {
        // First run?
        if (!trigger.LastFiredAt.HasValue)
            return true;

        var timeSinceLastRun = DateTime.UtcNow - trigger.LastFiredAt.Value;

        return config.IntervalType.ToLower() switch
        {
            "minutes" => timeSinceLastRun.TotalMinutes >= config.IntervalValue,
            "hours" => timeSinceLastRun.TotalHours >= config.IntervalValue,
            "days" => timeSinceLastRun.TotalDays >= config.IntervalValue,
            _ => false
        };
    }
}
```

**它如何运作 :**

1. 每分每秒 都打着点火电话 `ExecuteScheduledWorkflowsAsync()`
2. 我们查询已启用的时间表触发器
3. 检查是否已经足够时间
4. 如果是“% ,” , 请执行工作流程
5. 以上次运行时间更新触发状态

## APP投票

我们监控外部的API, 当内容改变时触发工作流程@!#

### 配置模型

```csharp
public class ApiPollTriggerConfig
{
    public string Url { get; set; } = string.Empty;
    public int IntervalSeconds { get; set; } = 300; // 5 minutes
    public bool AlwaysTrigger { get; set; } = false;
    public Dictionary<string, string>? Headers { get; set; }
}
```

### 投票工作

```csharp
[AutomaticRetry(Attempts = 3)]
public async Task PollApiTriggersAsync()
{
    _logger.LogInformation("Polling API triggers");

    var triggers = await _context.WorkflowTriggerStates
        .Include(t => t.WorkflowDefinition)
        .Where(t => t.IsEnabled && t.TriggerType == "ApiPoll")
        .ToListAsync();

    foreach (var trigger in triggers)
    {
        try
        {
            var config = JsonSerializer.Deserialize<ApiPollTriggerConfig>(
                trigger.ConfigJson);

            if (config == null) continue;

            // Check if it's time to poll
            if (trigger.LastCheckedAt.HasValue)
            {
                var timeSinceLastCheck = DateTime.UtcNow - trigger.LastCheckedAt.Value;
                if (timeSinceLastCheck.TotalSeconds < config.IntervalSeconds)
                    continue;
            }

            _logger.LogInformation("Polling API for workflow {WorkflowId}",
                trigger.WorkflowDefinition.WorkflowId);

            // Poll the API
            using var httpClient = new HttpClient();
            var response = await httpClient.GetAsync(config.Url);
            var content = await response.Content.ReadAsStringAsync();

            // Get previous state
            var state = JsonSerializer.Deserialize<Dictionary<string, object>>(
                            trigger.StateJson) ?? new();

            var previousHash = state.GetValueOrDefault("contentHash")?.ToString();
            var currentHash = ComputeHash(content);

            // Has content changed?
            if (previousHash != currentHash || config.AlwaysTrigger)
            {
                _logger.LogInformation(
                    "API content changed, triggering workflow {WorkflowId}",
                    trigger.WorkflowDefinition.WorkflowId);

                // Pass response as input to workflow
                var inputData = new Dictionary<string, object>
                {
                    ["apiResponse"] = content,
                    ["statusCode"] = (int)response.StatusCode,
                    ["previousHash"] = previousHash ?? string.Empty,
                    ["currentHash"] = currentHash
                };

                // Execute the workflow
                await _executionService.ExecuteWorkflowAsync(
                    trigger.WorkflowDefinition.WorkflowId,
                    inputData,
                    $"ApiPoll:{config.Url}");

                trigger.LastFiredAt = DateTime.UtcNow;
                trigger.FireCount++;

                // Update state
                state["contentHash"] = currentHash;
                state["lastContent"] = content.Length > 1000
                    ? content.Substring(0, 1000)
                    : content;
                state["lastPoll"] = DateTime.UtcNow.ToString("O");
            }

            trigger.LastCheckedAt = DateTime.UtcNow;
            trigger.StateJson = JsonSerializer.Serialize(state);
            trigger.LastError = null;

            await _context.SaveChangesAsync();
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error polling API trigger {TriggerId}",
                trigger.Id);
            trigger.LastError = ex.Message;
            trigger.LastCheckedAt = DateTime.UtcNow;
            await _context.SaveChangesAsync();
        }
    }
}

private string ComputeHash(string content)
{
    using var sha256 = System.Security.Cryptography.SHA256.Create();
    var bytes = System.Text.Encoding.UTF8.GetBytes(content);
    var hash = sha256.ComputeHash(bytes);
    return Convert.ToBase64String(hash);
}
```

**它如何运作 :**

1. 每分钟检查所有API投票的触发器
2. 每个触发器,检查自上次投票以来是否已经过了足够时间
3. 投放配置的 URL
4. 计算回复内容的散列
5. 与以前储存在州内的散列相比
6. 如果更改了 @ (@ {% or `AlwaysTrigger` 执行工作流程
7. 将API回复作为输入数据传送到工作流程
8. 以新的散列更新状态

### 使用实例示例

**监视 GitHub 发布@: @%**

```json
{
  "triggerType": "ApiPoll",
  "config": {
    "url": "https://api.github.com/repos/dotnet/aspnetcore/releases/latest",
    "intervalSeconds": 3600,
    "alwaysTrigger": false
  }
}
```

当新版本发布后, 内容会更改 hash changes @,和工作流程与发行数据执行@!

## 挂牌点火工作

在你的 `Program.cs` 或启动配置@: @% 1

```csharp
// Add Hangfire services
builder.Services.AddHangfire(config =>
{
    config.UsePostgreSqlStorage(
        builder.Configuration.GetConnectionString("DefaultConnection"));
});

builder.Services.AddHangfireServer();

// Register our job
builder.Services.AddScoped<WorkflowSchedulerJob>();
```

程序启动后 @,#注册重复性工作@:}

```csharp
app.UseHangfireDashboard("/hangfire");

// Register recurring jobs
RecurringJob.AddOrUpdate<WorkflowSchedulerJob>(
    "scheduled-workflows",
    job => job.ExecuteScheduledWorkflowsAsync(),
    Cron.Minutely);

RecurringJob.AddOrUpdate<WorkflowSchedulerJob>(
    "api-poll-triggers",
    job => job.PollApiTriggersAsync(),
    Cron.Minutely);
```

## 死火套板

校对:Portnoy `/hangfire`:

- **工作职位**: 参见所有队列中的{,} process *\ MS K2 和已完成的工作
- **经常性工作**: 管理工作流程调度器
- **重试**: 视图和重试失败的工作
- **服务器服务器**@:_Monitor 挂机服务器

### 保护仪表板的安全

```csharp
app.UseHangfireDashboard("/hangfire", new DashboardOptions
{
    Authorization = new[]
    {
        new HangfireAuthorizationFilter()
    }
});

public class HangfireAuthorizationFilter : IDashboardAuthorizationFilter
{
    public bool Authorize(DashboardContext context)
    {
        var httpContext = context.GetHttpContext();

        // Only allow authenticated users
        return httpContext.User.Identity?.IsAuthenticated == true;
    }
}
```

## 通过 UI 管理触发器

添加用于创建和管理触发器的UI@: @%

```csharp
[HttpPost("workflow/{id}/triggers")]
public async Task<IActionResult> CreateTrigger(
    string id,
    [FromBody] TriggerCreateRequest request)
{
    var workflow = await _context.WorkflowDefinitions
        .FirstOrDefaultAsync(w => w.WorkflowId == id);

    if (workflow == null)
        return NotFound();

    var trigger = new WorkflowTriggerStateEntity
    {
        WorkflowDefinitionId = workflow.Id,
        TriggerType = request.Type,
        ConfigJson = JsonSerializer.Serialize(request.Config),
        StateJson = "{}",
        IsEnabled = true
    };

    await _context.WorkflowTriggerStates.AddAsync(trigger);
    await _context.SaveChangesAsync();

    return Json(new { success = true, triggerId = trigger.Id });
}

public class TriggerCreateRequest
{
    public string Type { get; set; } = string.Empty; // Schedule, ApiPoll
    public object Config { get; set; } = new();
}
```

### UI 构成部分

```html
<div class="card bg-base-100 shadow-xl">
    <div class="card-body">
        <h2 class="card-title">⏰ Add Trigger</h2>

        <div class="form-control">
            <label class="label">Trigger Type</label>
            <select class="select select-bordered" x-model="triggerType">
                <option value="Schedule">Schedule</option>
                <option value="ApiPoll">API Poll</option>
            </select>
        </div>

        <!-- Schedule Config -->
        <template x-if="triggerType === 'Schedule'">
            <div class="space-y-4">
                <div class="form-control">
                    <label class="label">Interval</label>
                    <div class="flex gap-2">
                        <input type="number"
                               x-model="scheduleConfig.intervalValue"
                               class="input input-bordered flex-1" />
                        <select x-model="scheduleConfig.intervalType"
                                class="select select-bordered">
                            <option value="minutes">Minutes</option>
                            <option value="hours">Hours</option>
                            <option value="days">Days</option>
                        </select>
                    </div>
                </div>
            </div>
        </template>

        <!-- API Poll Config -->
        <template x-if="triggerType === 'ApiPoll'">
            <div class="space-y-4">
                <div class="form-control">
                    <label class="label">API URL</label>
                    <input type="url"
                           x-model="apiConfig.url"
                           class="input input-bordered"
                           placeholder="https://api.example.com/data" />
                </div>

                <div class="form-control">
                    <label class="label">Poll Interval (seconds)</label>
                    <input type="number"
                           x-model="apiConfig.intervalSeconds"
                           class="input input-bordered"
                           value="300" />
                </div>
            </div>
        </template>

        <button @click="createTrigger()" class="btn btn-primary mt-4">
            Create Trigger
        </button>
    </div>
</div>
```

## 世界工作流量实例

建立完整的自动工作流程,

1. 将GitHubAPI投放新释放
2. 检查版本是否比 We'+ @ ve 所见更新
3. 日志消息
4. @(_@Could 发送电子邮件@,}寄至 Slack,}等等 @MS K3}

### 创建工作流程

```json
{
  "name": "GitHub Release Monitor",
  "startNodeId": "parse-data",
  "nodes": [
    {
      "id": "parse-data",
      "type": "Transform",
      "name": "Extract Version",
      "inputs": {
        "operation": "json_parse",
        "data": "{{apiResponse}}"
      }
    },
    {
      "id": "log-release",
      "type": "Log",
      "name": "Log New Release",
      "inputs": {
        "message": "New release: {{tag_name}} - {{name}}",
        "level": "info"
      }
    }
  ],
  "connections": [
    {
      "sourceNodeId": "parse-data",
      "targetNodeId": "log-release"
    }
  ]
}
```

### 步骤 @2: 创建 API Poll 触发器

```json
{
  "type": "ApiPoll",
  "config": {
    "url": "https://api.github.com/repos/dotnet/aspnetcore/releases/latest",
    "intervalSeconds": 3600
  }
}
```

{\fn黑体\fs22\bord1\shad0\3aHBE\4aH00\fscx67\fscy66\2cHFFFFFF\3cH808080}

1. 将GitHub API扑灭
2. 将内容( hash) 与前一次民调比较
3. 如果更改了@ , 执行工作流程
4. 工作流程解析 JSON 并记录发布信息

## 监测和观察

### 伐木

所有工作流程的处决都记录下来了 :

```csharp
_logger.LogInformation(
    "Workflow {WorkflowId} execution {ExecutionId} completed in {Duration}ms with status {Status}",
    execution.WorkflowId,
    execution.Id,
    execution.DurationMs,
    execution.Status);
```

### 计量数

我们可以加上普罗米修斯的衡量标准 :

```csharp
private static readonly Counter WorkflowExecutions = Metrics
    .CreateCounter("workflow_executions_total",
        "Total workflow executions",
        new CounterConfiguration
        {
            LabelNames = new[] { "workflow_id", "status" }
        });

// In execution service
WorkflowExecutions
    .WithLabels(workflow.Id, execution.Status.ToString())
    .Inc();
```

### 警报报警

为:设置警报

- 失败的工作流程 @ ( @ status @ MPK1 @ 失败@ MS K2#
- 工作流动时间太长
- AIP 投票失败
- 触发在预期时间框架内发射的触发器@' @t

## 业绩考量

### 数据库负载

由于许多工作流程的民意调查经常@, 数据库载荷可能相当大 @:

**解决方案@:批量查询**

```csharp
// Instead of querying per trigger
var triggers = await _context.WorkflowTriggerStates
    .Include(t => t.WorkflowDefinition)
    .Where(t => t.IsEnabled && t.TriggerType == "ApiPoll")
    .AsNoTracking() // Read-only
    .ToListAsync();
```

### APIP率限制

当对外投票时 APIs:

**解答@: @ 指数回落**

```csharp
catch (HttpRequestException ex) when (ex.StatusCode == HttpStatusCode.TooManyRequests)
{
    // Back off
    var retryAfter = response.Headers.RetryAfter?.Delta ?? TimeSpan.FromMinutes(5);
    state["backoffUntil"] = DateTime.UtcNow.Add(retryAfter).ToString("O");
}
```

## 高级特征

### 有条件触发器

只有满足某些条件才能触发 :

```csharp
public class ConditionalTriggerConfig : ApiPollTriggerConfig
{
    public string? Condition { get; set; } // e.g., "{{stars}} > 1000"
}
```

### 触发

连锁触发器 @-一个工作流程@'完成触发另一个#:

```csharp
// After workflow completes
if (execution.Status == WorkflowExecutionStatus.Completed)
{
    var dependentTriggers = await _context.WorkflowTriggerStates
        .Where(t => t.TriggerType == "WorkflowComplete" &&
                    t.ConfigJson.Contains(execution.WorkflowId))
        .ToListAsync();

    foreach (var trigger in dependentTriggers)
    {
        await _executionService.ExecuteWorkflowAsync(
            trigger.WorkflowDefinition.WorkflowId,
            execution.OutputData,
            $"Triggered by {execution.WorkflowId}");
    }
}
```

## 夜间工作测试

单位测试您的工作@: @%

```csharp
[Fact]
public async Task ExecuteScheduledWorkflows_ShouldExecuteWhenIntervalPassed()
{
    // Arrange
    var mockContext = CreateMockContext();
    var mockExecutionService = new Mock<IWorkflowExecutionService>();
    var job = new WorkflowSchedulerJob(mockContext.Object,
        mockExecutionService.Object, Mock.Of<ILogger>());

    // Act
    await job.ExecuteScheduledWorkflowsAsync();

    // Assert
    mockExecutionService.Verify(s => s.ExecuteWorkflowAsync(
        It.IsAny<string>(),
        It.IsAny<Dictionary<string, object>>(),
        "Scheduler",
        It.IsAny<CancellationToken>()), Times.Once);
}
```

## 结论结论

我们的工作流程现在可以 :了

✅ **按时间表运行** @ - @ hourly @ , @ day=,}或自定义间隔
✅ **票价价格指数** - 监测外部服务的变化
✅ **音轨状态** 记住我们所见过的
✅ **自动\ - retry** - 处理中转失败
✅ **监测监视器** 用于所有工作的-布板
✅ **比例分摊比额表** 上火控制负载平衡

## 完整系列

我们从头到尾建立了企业工作流程系统 -

- **部分#1**介绍和建筑
- **部分#2**:核心工作流程引擎
- **部分#3**: 视觉工作流程编辑器
- **部分#4**校对:Soup

你现在有:了

- 强大的工作流程引擎
- 美丽的视觉编辑
- 自动执行
- AIPI监测
- 完全可观测

## 什么是' 下一步 @?

可能的增强@: @%

- **Webhoooks 网络图**通过 HTTP 端点触发工作流程
- **电子邮件节点**: 从工作流程发送电子邮件
- **数据库节点**:查询数据库
- **AI 节点**: 与LLMS结合
- **工作流量**: 合成工作流程
- **工作流程市场**共享工作流程模板

## 源代码

所有代码都可在仓库中获取@: @%

- 挂机任务 @: `Mostlylucid.SchedulerService/Jobs/`
- 工作流量模型 `Mostlylucid.Workflow.Shared/`
- 工作流程引擎+: `Mostlylucid.Workflow.Engine/`

感谢您关注此系列 <!}快乐工作流程建设_!> _🎉