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Table / Pagination / Download

Use a table with pagination to display large (100k+ rows) tabular data and provide data download option.

from h2o_wave import main, app, Q, uiimport csv

rows = [str(i + 1) for i in range(100)]rows_per_page = 10

@app('/demo')async def serve(q: Q):    if not q.app.initialized:        # Allow downloading all data since no filters/search/sort is allowed.        # Create and upload a CSV file for downloads.        # For multi-user apps, the tmp file name should be unique for each user, not hardcoded.        with open('data_download.csv', 'w') as csvfile:            csv_writer = csv.writer(csvfile, delimiter=',')            for r in rows:                csv_writer.writerow([r])        q.app.data_download, = await q.site.upload(['data_download.csv'])        q.app.initialized = True
    if not q.client.initialized:        q.page['meta'] = ui.meta_card(box='')        q.page['form'] = ui.form_card(box='1 1 -1 -1', items=[            ui.table(                name='table',                columns=[ui.table_column(name='text', label='Text', link=False)],                rows=[ui.table_row(name=r, cells=[r]) for r in rows[0:rows_per_page]],                pagination=ui.table_pagination(total_rows=len(rows), rows_per_page=rows_per_page),                height='580px',                downloadable=True,                events=['page_change', 'download']            )        ])        q.client.initialized = True
    if q.events.table:        if q.events.table.download:            q.page['meta'].script = ui.inline_script(f'window.open("{q.app.data_download}")')        if q.events.table.page_change:            offset = q.events.table.page_change.get('offset', 0)            new_rows = rows[offset:offset + rows_per_page]            q.page['form'].items[0].table.rows = [ui.table_row(name=r, cells=[r]) for r in new_rows]
    await q.page.save()

Tags:  download  form  pagination  table