Javascript 使用查询字符串的最终搜索
这是一个很长的问题,请耐心听我说 我们有一个运行在Express、Mongo、React和Redux上的应用程序。我已经编写了中间件和路由处理程序,它们通过获取查询字符串来处理传入的请求 以下是后端的代码:Javascript 使用查询字符串的最终搜索,javascript,node.js,reactjs,express,query-string,Javascript,Node.js,Reactjs,Express,Query String,这是一个很长的问题,请耐心听我说 我们有一个运行在Express、Mongo、React和Redux上的应用程序。我已经编写了中间件和路由处理程序,它们通过获取查询字符串来处理传入的请求 以下是后端的代码: 后端:节点,Express Peopleservices.js const people = require("../models/Person"); // creating the filter function const findBy = filter => { // lo
const people = require("../models/Person");
// creating the filter function
const findBy = filter => {
// loop on filter props
const query = {};
for (prop in filter) {
// if the prop contains gt or lt we should change it to mongo style query
if (prop.includes("_")) {
let finalQuery = {};
let parts = prop.split("_");
query[parts[0]] = parts[1];
finalQuery[`$${parts[1]}`] = filter[prop];
query[parts[0]] = finalQuery;
} else {
// if the prop does not containg gt or lt, just return the same query
query[prop] = filter[prop];
}
}
// finally, return the query
return people.find(query);
};
module.exports = {
findBy
};
module.exports = app => {
// calling services
const service = require("../services/peopleService");
// Route to handle everyone
app.get(["/everyone"], async (req, res) => {
try {
const filter = req.query || {};
const all = await service.findBy(filter);
res.status(200).send(all);
} catch (ex) {
next(ex);
}
});
};
这就是我们获取查询字符串并转换为mongo可理解查询的地方
PeopleRouters.js
const people = require("../models/Person");
// creating the filter function
const findBy = filter => {
// loop on filter props
const query = {};
for (prop in filter) {
// if the prop contains gt or lt we should change it to mongo style query
if (prop.includes("_")) {
let finalQuery = {};
let parts = prop.split("_");
query[parts[0]] = parts[1];
finalQuery[`$${parts[1]}`] = filter[prop];
query[parts[0]] = finalQuery;
} else {
// if the prop does not containg gt or lt, just return the same query
query[prop] = filter[prop];
}
}
// finally, return the query
return people.find(query);
};
module.exports = {
findBy
};
module.exports = app => {
// calling services
const service = require("../services/peopleService");
// Route to handle everyone
app.get(["/everyone"], async (req, res) => {
try {
const filter = req.query || {};
const all = await service.findBy(filter);
res.status(200).send(all);
} catch (ex) {
next(ex);
}
});
};
然后我们用正确的查询调用路由器
2。前端:反应,重复
我们将通过用户交互生成查询字符串,有三个输入字段,即姓名,性别,和年龄。根据给定的组合,我们创建要发送到服务器的最终查询字符串。这是这样做的:
从用户捕获数据的表单:
App.js
render() {
// the form, ideally could have it's own component
return (
<div className="ui container">
<div className="row" />
<div className="row">
<div className="ui two column centered grid">
<div className="column">
<div className="ui form">
<form className="ui form" onSubmit={this.handleSubmit}>
<div className="field">
<label>Name:</label>
<input
type="text"
name="name"
value={this.state.name}
onChange={this.handleChange}
/>
</div>
<div className="field">
<select
name="age"
value={this.state.age}
onChange={this.handleChange}
>
<option value="">Select Age Range</option>
<option value="_gte=20">Above 20</option>
<option value="_lt=20">Below 20</option>
</select>
</div>
<div className="field">
<select
className="ui fluid dropdown"
name="gender"
value={this.state.gender}
onChange={this.handleChange}
>
<option value="">Select Gender</option>
<option value="female">Female</option>
<option value="male">Male</option>
</select>
</div>
<div className="ui buttons">
<button type="submit" className="ui positive button active">
Search
</button>
</div>
</form>
</div>
</div>
</div>
</div>
<div className="ui link cards">{this.renderContent()}</div>
</div>
);
}
一旦我们将所有用户数据存储在状态中,我们将其传递给我们的动作创建者:
import axios from "axios";
import { FETCH_PEOPLE } from "./types";
export const fetchPeople = (...args) => async dispatch => {
// launching the default state
if (!args[0] && !args[1] && !args[2]) {
const response = await axios.get(`/everyone`);
dispatch({ type: FETCH_PEOPLE, payload: response });
}
// if the name is empty, we will run the query for the gender and age
else if (!args[0] && args[1] && args[2]) {
console.log("we here?");
const response = await axios.get(
`/everyone?age${args[1]}&gender=${args[2]}`
);
dispatch({ type: FETCH_PEOPLE, payload: response });
} else {
// populating with user's input
const response = await axios.get(
`/everyone?name=${args[0]}&age${args[1]}&gender=${args[2]}`
);
dispatch({ type: FETCH_PEOPLE, payload: response });
}
};
Action creator使用Axios发出请求,并显示结果。但是正如你所看到的,我只能做一点点的if和else,以得到一些组合。因此,我正在寻找一种更好的方法
我试过什么?
render() {
// the form, ideally could have it's own component
return (
<div className="ui container">
<div className="row" />
<div className="row">
<div className="ui two column centered grid">
<div className="column">
<div className="ui form">
<form className="ui form" onSubmit={this.handleSubmit}>
<div className="field">
<label>Name:</label>
<input
type="text"
name="name"
value={this.state.name}
onChange={this.handleChange}
/>
</div>
<div className="field">
<select
name="age"
value={this.state.age}
onChange={this.handleChange}
>
<option value="">Select Age Range</option>
<option value="_gte=20">Above 20</option>
<option value="_lt=20">Below 20</option>
</select>
</div>
<div className="field">
<select
className="ui fluid dropdown"
name="gender"
value={this.state.gender}
onChange={this.handleChange}
>
<option value="">Select Gender</option>
<option value="female">Female</option>
<option value="male">Male</option>
</select>
</div>
<div className="ui buttons">
<button type="submit" className="ui positive button active">
Search
</button>
</div>
</form>
</div>
</div>
</div>
</div>
<div className="ui link cards">{this.renderContent()}</div>
</div>
);
}
- 我尝试过重构过滤器,并在服务器端使用query.params
- 我已强制用户输入所有字段(简单案例)
- 我制作了一个向导表单,收集了所有数据并发送了结果
- 我已经编写了一段代码,用于解析接收到的状态,并根据长度创建了查询字符串
我亲爱的工程师朋友,聪明的人,在这件事上给我启发吧!我真的不喜欢那些if和else!这些都是罪 您可以这样简化它:-
//Pass object with keys and values from form values as arguments
this.props.fetchPeople({
name: this.state.name,
age: this.state.age,
gender: this.state.gender
});
// or more flexible approach will be to spread user input values
this.props.fetchPeople({...this.state});
// Make a genQueryString function
const genQueryString = (args={}) => {
let queryString = "";
Object.keys(args).forEach((key) => {
if(args[key]) {
if(key === "age") {
queryString+= `${key}${args[key]}&`;
} else {
queryString+= `${key}=${args[key]}&`
}
}
});
return queryString;
}
export const fetchPeople = (args) => async dispatch => {
const response = await axios.get(
`/everyone?${genQueryString(args)}`
);
dispatch({ type: FETCH_PEOPLE, payload: response });
}
};
或者,您也可以使用npm库(如qs)从参数生成查询字符串,这将提供更多方法:-
这里有很多。我认为如果你能把注意力集中在这个问题上,删除一些没有增加问题的代码,这会有所帮助。如果我理解正确:您正在询问如何处理传递给
fetchPeople
的任意数量的位置参数。理论上,它可以得到['name','','gender']
或['','age','gender']
或这三个值的任意组合。您需要将它映射到用于HTTP请求的命名键/值对?没错,有很多!我只是想让它尽可能全面。。你说得很对。这里的问题是尝试根据用户输入生成查询字符串,例如,如果用户将“name”留空,并填写“age”和“gender”,我们的查询字符串如下->所有人?name=&age\u gt=20&gender=male!其他情况也是如此!你看,使用这个查询字符串,我们无法从服务器获得任何合理的结果,这就是这里的问题…伙计!我不想降低答案的等级,但如果将对象连接到字符串,则会发出如下请求->“您尝试过解决方案吗?它不会像你说的那样。您需要接收fetch people中的第一个参数,它将是一个对象。不要在fetch people中传播参数。是的,我们得到typeError,因为我们无法将未定义或null转换为objectObject.keys(args).forEach(key=>{您是否像上面提到的那样使用对象调用fetch people?似乎您没有传递对象。