Thinking on demand development

This demand is compared with the last online upgrade demand , It belongs to a relatively large demand , Contains UI、 signal communication 、 Configuration modification and other parts , It basically involves all aspects of the project .
Because it is the demand received after returning from vacation , So I spent a lot of time getting familiar with the code in the early stage 、 Familiar with needs .
At the same time, there are still many gains in this demand .
From the three aspects of a demand, let's talk about the harvest .

Early familiarity ：

Be familiar with a need , Personally, I think we should clarify several issues ：
1、 What is the purpose of the requirement ？
Demand is to solve problems , The first thing is to find out what the purpose of requirements is .
The demand of this new Chengfeng access is to realize the dynamic generation of forms , Avoid upgrading traditional forms after fixing 、 Update the more troublesome situation .
Maintain the form by Json data + Form generation engine .
Adopt Abstract configuration items , The overall architecture is very flexible , The cost of subsequent maintenance iterations is significantly reduced , There is no need to change the code at the front and back ends of the Chengfeng side , Update the code on the device side to complete the configuration .

2、 What needs to be done ？
How should requirements be realized ？ What is the goal achieved ？
After figuring out the problem , You can really master 、 Understand the details of this requirement and how to do it , What protocol is used to complete , How about the overall communication link .
The implementation of this requirement adopts Json Make a communication protocol , And the server webSockt, stay webSocket After binding , Complete a series of subsequent communication work and complete various goals of the dynamic form .

What I didn't do well in the early familiarization stage of this demand is that I didn't understand these two problems , As a result, I always feel unable to grasp the main line in the subsequent development process , As a result, it has not been very efficient to complete the development .

Medium term development ：

In the process of mid-term development , What you are familiar with in the early stage is well reflected in this link .
Because I didn't do well in the familiarization stage of early needs , As a result, I haven't grasped the whole well in the process of this development , I feel like I can do whatever I want , It's not accurate 、 Clear goals to go , As a result, I often don't know where the next part is after I finish one part every time .
In the development phase , You should not rush to develop , But to understand 、 Find out what you want to do , What part do you want to develop now , What changes will be made after this part is finished , What is the next part ？ That is to have a clear sense of the whole , Understand the context of development , This confusion must not happen in the future .
Spend more time on preliminary design ！

Late joint commissioning ：

During the joint commissioning , My biggest problem is that I don't communicate strictly according to the provided documents .
Because there are many changes to the communication protocol this time , Entities sent by themselves often appear Bean No response , Or it cannot be parsed .
In this case , The first thing to do is to confirm the entity Bean Whether to communicate according to the communication protocol .
In the process of joint commissioning, we should make clear each functional module , And the possible boundary conditions of the function .

Harvest summary ：

1、 Before requirements development, we must understand the requirements .
2、Json Parsing ：
(1) Constant for fields , The field will be given a default value , If the field is an object variable , If the field has no assignment, it defaults to empty , This feature can be used to make polymorphic fields Json analysis .
(2) Double Follow Integer Cannot be forced
(3) For recursive Json analysis , have access to JSONObject To parse all {} situation , Use JSONArray analysis [] The situation of .
3、 For complex Json Generate , Ask