CODEWITHSUNDEEP
javascriptjsonchartsgoogle-visualizationlinechart
SnapzTry
SnapzTry

Reputation: 31

What to write in JSON file to create multiple line chart HTML

I'm new to javascript so please forgive me. I am trying to make a line chart (with 4 lines) which get updated every hour. The information will be found in a JSON file however I am unsure how to write it. Previously I have tried to use data.addColumn() and data.addRows() but I couldn't find a way to connec that with a JSON file. Say if you were to make an example, please show the number of sales of four different items

    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>

        google.charts.load('current', {
        packages: ['corechart']
        }).then(function () {

        var options = {
            hAxis: {
            title: 'Time'
            },
            vAxis: {
            title: 'Sales'
            },
            title: 'Today',
            height: 600
        };

        var chart = new google.visualization.LineChart(document.getElementById('dagens'));

        var jsonData = $.ajax({
            url: 'getData.php',
            dataType: 'json',
        })

            drawChart(jsonData);

        }).done(drawChart);


        function drawChart(jsonData) {
            var data = new google.visualization.DataTable(jsonData);
            chart.draw(data, options);
        }

    </script>

In the getData.php file this is written:

$string = file_get_contents("sampleData.json");
echo $string;

I wish to use google's chart system if possible. Many thanks in advance.

Edit: JSON file:

{
  cols: [{label: 'Time', type: 'number'},
         {label: 'Sales 1', type: 'number'},
         {label: 'Sales 2', type: 'number'},
     {label: 'Sales 3', type: 'number'},
     {label: 'Sales 4', type: 'number'}
  ],
  rows: [
     {c:[{v: 0}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 1}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 2}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 3}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 4}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 5}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 6}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 7}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 8}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 9}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 10}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 11}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 12}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 13}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 14}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 15}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 16}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 17}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 18}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 19}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 20}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 21}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 22}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]},
     {c:[{v: 23}, {v: 1000}, {v: 1000}, {v: 1000}, {v: 1000}]}
  ]
}

Upvotes: 3

Views: 490

Answers (1)

WhiteHat
WhiteHat

Reputation: 61222

in order to create a google data table, directly from json, as follows... 

var data = new google.visualization.DataTable(jsonData);

the json data must be in a very specific format, found here.

as for the format of the data for a specific chart,
each has a specific format, the data format for line chart can be found here.

the first column in the data table represents the x-axis,
it can be of any type (date, number, string, etc...).

the following columns should all be numbers,
which represent each series in the chart, or line to be drawn.

so an example of the json needed to draw a line chart,
with a date on the x-axis,
and four lines is as follows... 

var jsonData = {
  "cols": [
    {"label": "Date", "type": "date"},
    {"label": "Sales A", "type": "number"},
    {"label": "Sales B", "type": "number"},
    {"label": "Sales C", "type": "number"},
    {"label": "Sales D", "type": "number"}
  ],
  "rows": [
    {"c":[{"v": "Date(2019, 10, 1)"}, {"v": 1000}, {"v": 2000}, {"v": 3000}, {"v": 4000}]},
    {"c":[{"v": "Date(2019, 11, 1)"}, {"v": 1000}, {"v": 2000}, {"v": 3000}, {"v": 4000}]},
    {"c":[{"v": "Date(2020, 0, 1)"}, {"v": 1000}, {"v": 2000}, {"v": 3000}, {"v": 4000}]},
    {"c":[{"v": "Date(2020, 1, 1)"}, {"v": 1000}, {"v": 2000}, {"v": 3000}, {"v": 4000}]}
  ]
};

when using ajax to get the json data,
do not use --> async: false -- this option has been deprecated.

instead use the done promise method, which will have the data as an argument. 

$.ajax({
  url: "getData.php",
  dataType: "json",
}).done(function (jsonData) {  // <-- json data argument
});

see following working snippet,
here, I use the fail promise method to hard-code the data,
since your php page cannot be reached from this site.
on your server, it should work without the fail method... 

google.charts.load('current', {
  packages: ['corechart']
}).then(function () {

  var options = {
    hAxis: {
      title: 'Time'
    },
    vAxis: {
      title: 'Sales'
    },
    title: 'Today',
    height: 600
  };

  var chart = new google.visualization.LineChart(document.getElementById('today'));

  $.ajax({
    url: 'getData.php',
    dataType: 'json',
  }).fail(function () {

    var jsonData = {
      "cols": [
        {"label": "Date", "type": "date"},
        {"label": "Sales A", "type": "number"},
        {"label": "Sales B", "type": "number"},
        {"label": "Sales C", "type": "number"},
        {"label": "Sales D", "type": "number"}
      ],
      "rows": [
        {"c":[{"v": "Date(2019, 10, 1)"}, {"v": 1000}, {"v": 2000}, {"v": 3000}, {"v": 4000}]},
        {"c":[{"v": "Date(2019, 11, 1)"}, {"v": 1000}, {"v": 2000}, {"v": 3000}, {"v": 4000}]},
        {"c":[{"v": "Date(2020, 0, 1)"}, {"v": 1000}, {"v": 2000}, {"v": 3000}, {"v": 4000}]},
        {"c":[{"v": "Date(2020, 1, 1)"}, {"v": 1000}, {"v": 2000}, {"v": 3000}, {"v": 4000}]}
      ]
    };

    drawChart(jsonData);

  }).done(drawChart);


  function drawChart(jsonData) {
    var data = new google.visualization.DataTable(jsonData);
    chart.draw(data, options);
  }

});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://www.gstatic.com/charts/loader.js"></script>
<div id="today"></div>

EDIT

there is a problem with the ajax call.
change from... 

    var jsonData = $.ajax({
        url: 'getData.php',
        dataType: 'json',
    })

        drawChart(jsonData);

    }).done(drawChart);

change to... 

    $.ajax({
        url: 'getData.php',
        dataType: 'json',
    }).done(drawChart);

also, it appears you're missing the closing bracket to the load statement promise.
try this code... 

google.charts.load('current', {
  packages: ['corechart']
}).then(function () {

  var options = {
    hAxis: {
      title: 'Time'
    },
    vAxis: {
      title: 'Sales'
    },
    title: 'Today',
    height: 600
  };

  var chart = new google.visualization.LineChart(document.getElementById('dagens'));

  $.ajax({
    url: 'getData.php',
    dataType: 'json',
  }).done(drawChart);


  function drawChart(jsonData) {
    var data = new google.visualization.DataTable(jsonData);
    chart.draw(data, options);
  }

});

Upvotes: 3

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