[Dataset page] Add filename/extension to download attribute

[tkohr]

PR adds filename/extension to download attribute for json and geojson files. Other file formats should have a name and don't need download attribute. Note that download attribute only takes effect on same-origin.

[f-necas]

Is the title retrieved from the data-api ? It could be used to set name of the file instead of data.

What append to let fileName = '' when it clicks on a csv format ?

[tkohr]

Is the title retrieved from the data-api ? It could be used to set name of the file instead of data.

Good point ! Completely forgot about that, added it now.

What append to let fileName = '' when it clicks on a csv format ?

Do you mean "why"? The download attribute does not seem to affect formats that cannot be opened by the browser. Filenames including extension behave already as expected in this case if I saw right, so I just keep it empty in this case.

[f-necas]

Hm, for me, if the format is, by example csv, it won't go through :

if (this.format === 'geojson') {
      completeFileName = `${fileName}.geojson`
    } else if (this.format === 'json') {
      completeFileName = `${fileName}.json`
    }

Then completeFileName will be empty.

[tkohr]

Yes, indeed, the logic will only be applied for json/geojson. If I remember correctly, the issue that the file is not being downloaded only occurs with these formats. Other fomats such as csv or xls do not seem to take the download attribute and its value into account. They are currently already getting downloaded with their title as filename.