web_frontend_note.md

• Web FrontEnd Note
  • reactJS
  • Ant.design
  • http request from JS
  • button click -> javascript
  • form submit -> javascript
  • get the content of a file
  • Html Number Input field, max/min length
  • Html Hidden Element
  • Html Drop List
  • Html dynamic show hide element

Web FrontEnd Note

reactJS

• create project

npm install -g create-react-app
create-react-app my-app

• run project

npm start
http://localhost:3000

Ant.design

• after you create reactJS app, cd to project folder, then run :

yarn add antd

• use antd
  • • 修改 src/App.css，在文件顶部引入 antd/dist/antd.css。

@import '~antd/dist/antd.css';

http request from JS

    // submit form data to api
    fetch( "http://10.192.83.42:9000/announcementPublish" ,  {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
      body: JSON.stringify( values)
    })
      .then(res => res.json())
      .then(
        (result) => {
            if (result.err) {
                alert( "有错误发生,发布失败!!" ); 
            } else {
                alert( "公告发布成功" );
                this.props.form.resetFields() ;
            }
        },
        // Note: it's important to handle errors here
        // instead of a catch() block so that we don't swallow
        // exceptions from actual bugs in components.
        (error) => {
            alert( error ) ;
        }
      )

button click -> javascript

const t_delete_page_html = `
<button onclick="deleteEvent()">删除当前活动</button>

<script>
function deleteEvent() {
    // submit form data to api
    fetch( window.location.origin + "/" + "deleteaccrecharge/" + {{.Game}}  ,  {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
      body: "{}" , 
    })
      .then(res => res.json())
      .then(
        (result) => {
            if (result.err) {
                alert( result.err ); 
            } else {
                // to reset page
                window.location.reload(true);
            }
        },
        // Note: it's important to handle errors here
        // instead of a catch() block so that we don't swallow
        // exceptions from actual bugs in components.
        (error) => {
            alert( error ) ;
        }
      )
}
</script>
`

form submit -> javascript

const t_add_page_html = `
<form name="form_event" onsubmit="addEvent(); return false;">
  <label>时间格式(北京时间): 2016010215</label><br>
  <label>活动开始时间</label><br>
  <input type="text" id="id_starttime" name="starttime" maxlength="10" placeholder="1970010208"><br>
  <label>统计截止时间</label><br>
  <input type="text" id="id_deadline" name="deadline" maxlength="10" placeholder="1970010214"> <br>
  <label>活动结束时间</label><br>
  <input type="text" id="id_endtime" name="endtime" maxlength="10" placeholder="1970010220"><br><br>

  <input type="submit" value="发布累冲活动">
</form> 


<script>
function isNumeric(num){
  return !isNaN(num)
}
function addEvent() {
    starttime =  document.form_event.elements["starttime"].value
    deadline =  document.form_event.elements["deadline"].value
    endtime =  document.form_event.elements["endtime"].value
    
    if ( starttime.length < 10 || deadline.length < 10 || endtime.length < 10   ) {
        alert( "请填写完整时间" ) ;
        return ;
    }
    if ( !isNumeric( starttime ) || !isNumeric( deadline ) ||  !isNumeric( endtime ) ) {
        alert( "时间不能包含非数字" ) ;
        return ;
    }

    let url =  window.location.origin + "/publishaccrecharge/" + {{.Game}} + "/"+starttime+"/"+deadline+"/"+endtime
    fetch( url ,  {
      method: 'POST',
      headers: {
        'Accept': 'application/json',
        'Content-Type': 'application/json',
      },
      body: "{}" , 
    })
      .then(res => res.json())
      .then(
        (result) => {
            if (result.err) {
                alert( result.err ); 
            } else {
                // to reset page
                window.location.reload(true);
            }
        },
        // Note: it's important to handle errors here
        // instead of a catch() block so that we don't swallow
        // exceptions from actual bugs in components.
        (error) => {
            alert( error ) ;
        }
      )
}
</script>
`

get the content of a file

<!DOCTYPE html>
<html>
<title>
get file content test
</title>
<body>

<p>Upload your file</p>

<script>
async function readText(event) {
  const file = event.target.files.item(0)
  const text = await file.text();

  console.log( text );

  // document.getElementById("output").innerText = text
}
</script>

<input type="file" onchange="readText(event)" />
<!-- <pre id="output"></pre> -->

</body>
</html>

Html Number Input field, max/min length

    <input type="number" id="id_starttime" name="starttime" minlength="10" maxlength="10" placeholder="1970010208" required oninput="javascript: if (this.value.length > this.maxLength) this.value = this.value.slice(0, this.maxLength);">

Html Hidden Element

    <form id="id_form_query">
        <!-- hideen filed -->
        <input type="hidden" name="action" value="query" />
        ...
        <button type="submit" form="id_form_query">Query</button>
    </form>

Html Drop List

    <select name="game" id="id_game" form="id_form_create">
        {{ range $index, $gamename := .GameList }}
        <option value="{{$gamename}}">{{$gamename}}</option>
        {{ end }}
    </select>

Html dynamic show hide element

    if ( bShow ) {
        elem.style.display = "block" ;
        // elem.style.display = "table-row" ; # for table row
    } else {
        elem.style.display = "none" ;
    }