我希望从页面中获取Google图表数据,将其转换为CSV格式,然后将其传递给下载器。
在chartpage.js文件中:
function downloadCSV(args) {
var csvData, filename, link;
var action = args.action_name;
var csv = convertArrayOfObjectsToCSV({
action_name: action
});
filename = args.filename || 'export.csv';
csvData = encodeURI(csv);
link = document.createElement('a');
link.setAttribute('href', 'data:text/csv;charset=utf-8,' + csvData);
link.setAttribute('type', 'data:text/csv;charset=utf-8');
link.setAttribute('download', filename);
link.click();
}
然后在 chart.coffee 中:
init_chart = ->
chart = new google.visualization.BarChart(document.getElementById('chart_div')); //#chart_div in chart.html.haml
render_chart = (items, year)->
@data = new google.visualization.DataTable()
data.addColumn 'string', I18n.t('charts.name')
// Other logic for building chart from Rails DB Data
for key_item in items
label = []
[key, item] = key_item.split(':')
if key == 'competitor_meded_involvement'
label.push I18n.t('charts.competitor')
label.push I18n.t("kol_items.#{item}")
data.addColumn 'number', label.join(' - ')
// and so on.
google.charts.load 'current', 'packages': ['corechart']
google.visualization.events.addListener(@data, 'ready', setData) // I read this was a solution but it doesn't seem to help
google.charts.setOnLoadCallback ->
init_chart()
render_chart()
$(setData(@data)) //I tried passing this to a setter method over in chartpage.js which takes @data and tries to set it globally but that makes no difference at page load time.
在 chart.html.haml 文件中:
%h5{id: "downloadCSV"}= link_to '<i class="fa fa-file-excel-o"></i> Download CSV'.html_safe, "#"
#chart_div
所以我在主JS中尝试了以上两种方法以及以下方法:
case 'chart_kol_comparison':
google.setOnLoadCallback(function() {
str = google.visualization.dataTableToCsv(window.data); //This builds the CSV string and returns it to the download JS for output
});
但页面的JS(HAML)中的数据变量:
@data = new google.visualization.DataTable()
似乎只有在页面加载后才可用 - 而不是在上面的JS加载并尝试抓取数据时。
当我在控制台中运行以下内容时,它可以工作,但页面加载时却不能。这是在Rails应用程序中。
str = google.visualization.dataTableToCsv(data); //var data is populated after page loads (available from console) but not from the JS at page load time.
我该如何开始处理这个问题?