inst/htmlwidgets/lib/plugins/dataloader/readme.md

amCharts Data Loader

Version: 1.0.19

Description

By default all amCharts libraries accept data in JSON format. It needs to be there when the web page loads, defined in-line or loaded via custom code.

This plugin introduces are native wrapper that enables automatic loading of data from external data data sources in CSV and JSON formats.

Most of the times you will just need to provide a URL of the external data source - static file or dynamically generated - and it will do the rest.

Important notice

Due to security measures implemented in most of the browsers, the external data loader will work only when the page with the chart or map is loaded via web server.

So, any of the examples loaded locally (file:///) will not work.

The page needs to be loaded via web server (http://) in order to work properly.

Loading data from another domain than the web page is loaded is possible but is a subject for Access-Control-Allow-Origin policies defined by the web server you are loading data from.

For more about loading data across domains use the following thread: http://stackoverflow.com/questions/1653308/access-control-allow-origin-multiple-origin-domains

Usage

1) Include the minified version of file of this plugin. I.e.:

<script src="amcharts/plugins/dataloader/dataloader.min.js" type="text/javascript"></script>

(this needs to go after all the other amCharts includes)

2) Add data source properties to your chart configuration.

Regular (Serial, Pie, etc.) charts:

AmCharts.makeChart( "chartdiv", {
  ...,
  "dataLoader": {
    "url": "data.json",
    "format": "json"
  }
} );

Stock chart:

AmCharts.makeChart( "chartdiv", {
  ...,
  "dataSets": [{
    ...,
    "dataLoader": {
      "url": "data.csv",
      "format": "csv",
      "delimiter": ",",       // column separator
      "useColumnNames": true, // use first row for column names
      "skip": 1               // skip header row
    }
  }]
} );

That's it. The plugin will make sure the files are loaded and dataProvider is populated with their content before the chart is built.

Some formats, like CSV, will require additional parameters needed to parse the data, such as "separator".

If the "format" is omitted, the plugin will assume JSON.

Using in object-based chart setup

If you’re still using object-based chart setup, assign dataLoader-related config object to chart object’s dataLoader property:

var chart = new AmCharts.AmSerialChart();
...
chart["dataLoader"] = {
  "url": "data.csv",
  "format": "csv",
  "delimiter": ",",
  "useColumnNames": true,
  "skip": 1
};

Complete list of available dataLoader settings

Property | Default | Description -------- | ------- | ----------- async | true | If set to false (not recommended) everything will wait until data is fully loaded complete | | Callback function to execute when loader is done delimiter | , | [CSV only] a delimiter for columns (use \t for tab delimiters) emptyAs | undefined | [CSV only] replace empty columns with whatever is set here error | | Callback function to execute if file load fails init | | Callback function to execute when Data Loader is initialized, before any loading starts format | json | Type of data: json, csv headers | | An array of objects with two properties (key and value) to attach to HTTP request load | | Callback function to execute when file is successfully loaded (might be invoked multiple times) noStyles | false | If set to true no styles will be applied to "Data loading" curtain numberFields | | [CSV only] An array of fields in data to treat as numbers postProcess | | If set to function reference, that function will be called to "post-process" loaded data before passing it on to chart. The handler function will receive two parameters: loaded data, Data Loader options progress | | Set this to function reference to track progress of the load. The function will be passed in three parameters: global progress, individual file progress, file URL. showErrors | true | Show loading errors in a chart curtain showCurtain | true| Show curtain over the chart area when loading data reload | 0 | Reload data every X seconds reverse | false | [CSV only] add data points in revers order skip | 0 | [CSV only] skip X first rows in data (includes first row if useColumnNames is used) skipEmpty | true | [CSV only] Ignore empty lines in data timestamp | false | Add current timestamp to data URLs (to avoid caching) useColumnNames | false | [CSV only] Use first row in data as column names when parsing

Using in JavaScript Stock Chart

In JavaScript Stock Chart it works exactly the same as in other chart types, with the exception that dataLoader is set as a property to the data set definition. I.e.:

var chart = AmCharts.makeChart("chartdiv", {
  "type": "stock",
  ...
  "dataSets": [{
    "title": "MSFT",
      "fieldMappings": [{
        "fromField": "Open",
        "toField": "open"
      }, {
        "fromField": "High",
        "toField": "high"
      }, {
        "fromField": "Low",
        "toField": "low"
      }, {
        "fromField": "Close",
        "toField": "close"
      }, {
        "fromField": "Volume",
        "toField": "volume"
      }],
      "compared": false,
      "categoryField": "Date",
      "dataLoader": {
        "url": "data/MSFT.csv",
        "format": "csv",
        "showCurtain": true,
        "showErrors": true,
        "async": true,
        "reverse": true,
        "delimiter": ",",
        "useColumnNames": true
      }
    }
  }]
});

Can I also load event data the same way?

Sure. You just add a eventDataLoader object to your data set. All the same settings apply.

Adding custom headers to HTTP requests

If you want to add additional headers to your data load HTTP requests, use "headers" array. Each header is an object with two keys: "key" and "value":

"dataLoader": {
  "url": "data/serial.json",
  "format": "json",
  "headers": [{
    "key": "x-access-token",
    "value": "123456789"
  }]
}

Manually triggering a reload of all data

Once chart is initialized, you can trigger the reload of all data manually by calling chart.dataLoader.loadData() function. (replace "chart" with the actual variable that holds reference to your chart object)

Using callback functions

Data Loader can call your own function when certain event happens, like data loading is complete, error occurs, etc.

To set custom event handlers, use these config options:

Example:

AmCharts.makeChart( "chartdiv", {
  ...,
  "dataSets": [{
    ...,
    "dataLoader": {
      "url": "data.json",
      "init": function ( options, chart ) {
        console.log( 'Loading started' );
      },
      "load": function ( options, chart ) {
        console.log( 'Loaded file: ' + options.url );
      },
      "complete": function ( chart ) {
        console.log( 'Woohoo! Finished loading' );
      },
      "error": function ( options, chart ) {
        console.log( 'Ummm something went wrong loading this file: ' + options.url );
      },
      "progress": function( totalPercent, filePercent, url ) {
        console.log( 'Total percent loaded: ' + Math.round( totalPercent ) );
      }
    }
  }]
} );

Using Data Loader's standalone functions

Data Loader's load and parsing functions are available for external standalone use.

The three available functions are as follows:

Function | Parameters | Description -------- | ---------- | ----------- AmCharts.loadFile() | url, options, callback | Loads the file and passes it into callback function (unparsed) AmCharts.parseCSV() | data, options | Parses data in string CSV format and returns JavaScript Array AmCharts.parseJSON() | data | Parses data in string JSON format and returns JavaScript Array

The options passed into standalone functions are the same as discussed in Complete list of available dataLoader settings chapter.

JSON Example

AmCharts.loadFile(dataset_url, {}, function(data) {
  var chartData = AmCharts.parseJSON(data);
  console.log(chartData); // this will output an array
});

CSV Example

AmCharts.loadFile(dataset_url, {}, function(data) {
  var chartData = AmCharts.parseCSV(data, {
    "delimiter": ",",
    "useColumnNames": true
  });
  console.log(chartData); // this will output an array
});

Translating into other languages

Depending on configuration options the plugin will display a small number of text prompts, like 'Data loading...'.

Plugin will try matching chart's language property and display text prompts in a corresponding language. For that the plugin needs to have the translations.

Some of the plugin translations are in lang subdirectory. Simply include the one you need.

If there is no translation to your language readily available, just grab en.js, copy it and translate.

The structure is simple:

'The phrase in English': 'Translation'

The phrase in English must be left intact.

When you're done, you can include your language as a JavaScript file.

P.S. send us your translation so we can include it for the benefits of other users. Thanks!

Requirements

This plugin requires at least 3.13 version of JavaScript Charts, JavaScript Stock Chart or JavaScript Maps.

Demos

They're all in subdirectory /examples.

Extending this plugin

You're encouraged to modify, extend and make derivative plugins out of this plugin.

You can modify files, included in this archive or, better yet, fork this project on GitHub:

https://github.com/amcharts/dataloader

We're curious types. Please let us know (contact@amcharts.com) if you do create something new out of this plugin.

License

This plugin is licensed under Apache License 2.0.

This basically means you're free to use or modify this plugin, even make your own versions or completely different products out of it.

Please see attached file "license.txt" for the complete license or online here:

http://www.apache.org/licenses/LICENSE-2.0

Contact us

Changelog

1.0.19

1.0.18

1.0.17

1.0.16

1.0.15

1.0.14

1.0.13

1.0.12

1.0.11

1.0.10

1.0.9

1.0.8

1.0.7

1.0.6

1.0.5

1.0.4

1.0.3

1.0.2

1.0.1

1.0

0.9.2

0.9.1

0.9



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rAmCharts documentation built on Dec. 6, 2019, 5:11 p.m.