Thomas Peetz
57 lines
2.3 KiB
JavaScript
57 lines
2.3 KiB
JavaScript
/*
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* Copyright 2000-2026 Vaadin Ltd.
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may not
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* use this file except in compliance with the License. You may obtain a copy of
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* the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations under
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* the License.
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*/
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/**
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* Triggers a file download from the given URL using the standard
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* <a href download> click pattern.
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*
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* The anchor is synthesised, clicked synchronously inside the caller's
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* gesture context, and removed. The browser then either navigates to the
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* URL (server responds with Content-Disposition: attachment) or saves the
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* resource directly when the download attribute applies.
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*
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* The {@code download} attribute is honoured only for same-origin URLs;
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* cross-origin responses must set Content-Disposition themselves for the
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* filename to take effect.
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*/
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function startDownload(url, filename) {
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const a = document.createElement('a');
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a.href = url;
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// Always set `download` so the browser saves the response rather than
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// navigating to it. Empty value lets the browser pick the filename from
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// Content-Disposition or the URL pathname; a non-empty value is the
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// suggested filename (honoured only same-origin). Cross-origin responses
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// without Content-Disposition: attachment still navigate — that's a
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// server-side concern this client helper can't override.
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a.download = filename ?? '';
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// Opt out of Vaadin's client-side router so the click reaches the
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// browser's native download handling instead of being intercepted as an
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// in-app navigation. Matches Anchor.setHref(DownloadHandler).
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a.setAttribute('router-ignore', '');
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// Hidden but in the document — some browsers ignore clicks on detached
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// anchors.
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a.style.display = 'none';
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document.body.appendChild(a);
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a.click();
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a.remove();
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}
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const $wnd = window;
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$wnd.Vaadin ??= {};
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$wnd.Vaadin.Flow ??= {};
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$wnd.Vaadin.Flow.download = {
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start: startDownload
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};
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export {};
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//# sourceMappingURL=Download.js.map
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