前端数据分析工具开发

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上传文件

上传文件的后端服务

使用 Python Flask 实现。

import os
from flask import Flask, request, redirect, url_for, send_from_directory
from werkzeug import secure_filename
from flask_cors import CORS

UPLOAD_FOLDER = '/path/to/the/uploads'
ALLOWED_EXTENSIONS = set(['txt', 'pdf', 'png', 'jpg', 'jpeg', 'gif'])

app = Flask(__name__)
CORS(app)
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER

def allowed_file(filename):
    return '.' in filename and \
           filename.rsplit('.', 1)[1] in ALLOWED_EXTENSIONS

@app.route('/', methods=['GET', 'POST'])
def upload_file():
    if request.method == 'POST':
        file = request.files['file']
        if file and allowed_file(file.filename):
            filename = secure_filename(file.filename)
            file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
            return redirect(url_for('uploaded_file',
                                    filename=filename))
    return '''
    <!doctype html>
    <title>Upload new File</title>
    <h1>Upload new File</h1>
    <form action="" method=post enctype=multipart/form-data>
      <p><input type=file name=file>
         <input type=submit value=Upload>
    </form>
    '''@app.route('/uploads/<filename>')
def uploaded_file(filename):
    return send_from_directory(app.config['UPLOAD_FOLDER'],
                               filename)

解决跨域访问，需安装 flask-cors

上传组件

使用 Element UI 实现

// action 指定上传文件后台服务, on-success 指定上传成功后执行的方法
<el-upload
    class="upload-demo"
          action="http://xxxx:xxxx/upload"
    :on-success="handleSuccess"
    :show-file-list="true"
    >
    <el-button size="small" type="primary"> 点击上传 </el-button>
    <div slot="tip" class="el-upload__tip"> 只能上传 txt 文件，分隔符为 \t</div>
</el-upload>

// 在 Vue 中指定数据 fileName、计算属性 fileContent、以及上传成功后的方法 handleSuccess
new Vue({
  el: '#app',
  data: {fileName: null},
    computed: {fileContent: function() {if(this.fileName != null) {return this.fileName.response;}
      }
  },
  methods: {handleSuccess: function(response, file, fileList) {
      this.fileName = file;
      return this.$confirm(` 上传 ${ file.name}成功！`);
    }
    }
});

TSV 解析

使用 d3-dsv 库。

<script src="https://d3js.org/d3-dsv.v1.min.js"></script>
d3.tsvParse("foo\tbar\n1\t2"); // [{foo: "1", bar: "2"}, columns: ["foo", "bar"]]

表格

使用 v -for 实现动态列名

<el-table :data="inputData" style="width: 100%" height="250">
      <el-table-column 
        v-for="col in columns"
        :prop="col" :label="col" >
      </el-table-column>
</el-table>

JS 数组操作

资料
创建、排序、删除、追加、reverse、slice、join 转字符串、concat 拼接数组、forEach 循环

JS 字符串操作

split 拆分、parseInt 等类型转换

事件

表格点击行事件

<el-table
      :data="getPageData()"
      style="width: 100%" @row-click="updateRow">
</el-table>

Leaflet 组件

Vue.component("leaflet", {props: ['table_data', 'selected_row'],
  data() {
    return {
      map: null,
      layer: null,
      point: null
    };
  },
  template: '<div></div>',
  mounted: function() {this.init();
    this.update();
    this.highlight();},
  watch: {table_data: function () {this.update();
    },
    selected_row: function() {this.highlight();
    }
  },
  methods: {init: function() {this.map = L.map(this.$el.id).setView([29.802946,106.396835], zoom = 10);
            L.tileLayer('https://rt{s}.map.gtimg.com/realtimerender?z={z}&x={x}&y={y}&type=vector&style=0',
                {
                    maxZoom: 18,
                    subdomains: "0123",
                    tms: true,
                    attribution: '&copy; <a href="http://map.qq.com/"> 腾讯地图 </a>',
                }
            ).addTo(this.map);
    },
        update: function() {if(this.layer != null) this.layer.removeFrom(this.map);
          if(this.point != null)  this.point.removeFrom(this.map);
          // 绘制数据
            var markerArray = Array();
            this.table_data.forEach((pnt) => {var date = new Date(pnt['collecttime']*1000);
                markerArray.push(L.circle([pnt["bmuserlat"], pnt["bmuserlng"]]).bindTooltip(date+""));
                // L.circle([pnt["bmuserlat"], pnt["bmuserlng"]], {radius:15}).addTo(this.map);
            });
            this.layer = L.featureGroup(markerArray).addTo(this.map);
            this.map.fitBounds(this.layer.getBounds());
        },
        highlight: function() {if(this.point != null)  this.point.removeFrom(this.map);
          // 绘制选中点
          if(this.selected_row != null) {this.point = L.circleMarker([this.selected_row['bmuserlat'], this.selected_row['bmuserlng']], {color: "red"}).addTo(this.map).bindPopup(this.selected_row['collecttime'] + ""); 
          }
        }
  }
});

ECharts 组件

Vue.component('echarts-heatmap', {props: ['table_data'],
  data: function() {
    return {map: null}
  },
  computed: {plot_data: function() {
      //GCJ-02 to BD-09
      function bd_encrypt(gcjLat, gcjLon)
      {
          x_pi = 3.14159265358979324 * 3000.0 / 180.0;
          var x = gcjLon, y = gcjLat;
          var z = Math.sqrt(x * x + y * y) + 0.00002 * Math.sin(y * x_pi);
          var theta = Math.atan2(y, x) + 0.000003 * Math.cos(x * x_pi);
          var bdLon = z * Math.cos(theta) + 0.0065;
          var bdLat = z * Math.sin(theta) + 0.006;
          return {'lat': bdLat, 'lon': bdLon};
      }
      
      var heatArray = Array();
      this.table_data.forEach(function(item) {var x = Math.round(item['bmuserlng'] * 1000) / 1000;
        var y = Math.round(item['bmuserlat'] * 1000) / 1000;
        var res = bd_encrypt(y, x);
        var x = res.lon;
        var y = res.lat;
        var idx = item["color_idx"]
        heatArray.push([x, y, idx]);
      });
      
      var heatMap = [];
      heatArray.reduce(function(res, value){if(!res[value]) {res[value] = value;
          heatMap.push(value);
        }
        return res;
      }, {});
      
      var result = [];
      heatMap.reduce(function(res, value) {k = [value[0], value[1]]
        if(!res[k]) {res[k] = [value[0], value[1], 0];
          result.push(res[k]);
        }
        res[k][2] += 1;
        return res;
      }, {});
      
      var max = 0;
      result.reduce(function(res, value){if(res < value[2]) {res = value[2];
          max = res;
        }
        return res;
      }, 0);
      //result = result.filter(word => word[2] == max);
      console.log(result);
      return(result);
    },
    option: function() {
      var points = this.plot_data;
      center = points.reduce(function(res, value){return [res[0] + value[0], res[1] + value[1]];
      }, [0,0]);
      let center_x = center[0] / points.length;
      let center_y = center[1] / points.length;
      return {
        animation: false,
        bmap: {center: [center_x, center_y],
            zoom: 14,
            roam: true
        },
        visualMap: {
            show: false,
            top: 'top',
            min: 0,
            max: 5,
            seriesIndex: 0,
            calculable: true,
            inRange: {color: ['blue', 'blue', 'green', 'yellow', 'red']
            }
        },
        series: [{
            type: 'heatmap',
            coordinateSystem: 'bmap',
            data: points,
            pointSize: 5,
            blurSize: 6
        }]}
      
    }
    
  }, 
  template: '<div></div>', 
  mounted: function() {this.initMap();
    this.updateMap();},
  watch: {table_data: function() {this.updateMap();
    }
  },
  methods: {initMap: function() {this.map = echarts.init(this.$el);
    } ,
    updateMap: function() {var app = {};
      app.title = '热力图与百度地图扩展';
      this.map.setOption(option = this.option);
      var bmap = this.map.getModel().getComponent('bmap').getBMap();
      bmap.addControl(new BMap.MapTypeControl());
      this.map.setOption(option, true);
    }
  }
  
});

正文完
发表至： javascript
2019-06-20
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