通过Node-red Dashboard获取数据

Question

我使用node-red通过MQTT获取数据。我在图片中有回应......

不，我想在功能的帮助下分别获取数据w.r.t Phase1，Phase2，Phase3，Phase4和Timestamp。我不知道如何这样做。 P.S我是node.red的新手。三江源

Answer 1

如果你只想从每个msg中获取数值，你可以使用from collections import UserDict # see also UserList, UserString class Treatment(UserDict): pass class Disease(UserDict): def __init__(self, **kwargs): super().__init__(**kwargs) self.treatments = [] class Patient(UserDict): def __init__(self, **kwargs): super().__init__(**kwargs) self.diseases = [] patients = dict() p1 = patients['0001'] = Patient(name='Eric', surname='Idle') d1 = Disease(name='Eating too much') t1 = Treatment(title='Radical Therapy', description='Mint pill after lunch.') d1.treatments.append(t1) d2 = Disease(name='Cannot Control the Legs Syndrome') t2 = Treatment(title='Conservative Approach', description='Have a seat.') d2.treatments.append(t2) p1.diseases.extend([d1,d2]) for pid in patients: print() print('PID:{} {} {}'.format(pid, patients[pid]['name'],\ patients[pid]['surname'])) print(50*'-') for disease in patients[pid].diseases: print() print('Disease: {}'.format(disease['name'])) for treatment in disease.treatments: print('Treatment: {}'.format(treatment['title'])) print('\t\t{}'.format(treatment['description'])) 节点来分割字符串，如下所示：

function

现在，您将拥有一个可以直接在仪表板元素中显示的主题和有效负载。

还有至少2个节点可以做同样的事情，而无需编写任何javascript代码。您可能希望安装并尝试var parts = msg.payload.split(":"); var value = parts.length > 1 ? parts[1].trim() : parts[0].trim(); // append the string before the ":" to the topic... msg.topic += "/" + parts.length > 1 ? parts[0] : "Total"; // coerce the value after the ":" to be numeric... msg.payload = +value; return msg; 节点 - 它适用于提取字符串。也可以使用node-red-contrib-string节点，但需要一个Jsonata表达式，这个表达式功能强大，但也比javascript代码复杂一点......