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Deep link to a native app from a browser, with a fallback
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| function DeepLinker(options) { | |
| if (!options) { | |
| throw new Error('no options') | |
| } | |
| var hasFocus = true; | |
| var didHide = false; | |
| // window is blurred when dialogs are shown | |
| function onBlur() { | |
| hasFocus = false; | |
| }; | |
| // document is hidden when native app is shown or browser is backgrounded | |
| function onVisibilityChange(e) { | |
| if (e.target.visibilityState === 'hidden') { | |
| didHide = true; | |
| } | |
| }; | |
| // window is focused when dialogs are hidden, or browser comes into view | |
| function onFocus() { | |
| if (didHide) { | |
| if (options.onReturn) { | |
| options.onReturn(); | |
| } | |
| didHide = false; // reset | |
| } else { | |
| // ignore duplicate focus event when returning from native app on | |
| // iOS Safari 13.3+ | |
| if (!hasFocus && options.onFallback) { | |
| // wait for app switch transition to fully complete - only then is | |
| // 'visibilitychange' fired | |
| setTimeout(function() { | |
| // if browser was not hidden, the deep link failed | |
| if (!didHide) { | |
| options.onFallback(); | |
| } | |
| }, 1000); | |
| } | |
| } | |
| hasFocus = true; | |
| }; | |
| // add/remove event listeners | |
| // `mode` can be "add" or "remove" | |
| function bindEvents(mode) { | |
| [ | |
| [window, 'blur', onBlur], | |
| [document, 'visibilitychange', onVisibilityChange], | |
| [window, 'focus', onFocus], | |
| ].forEach(function(conf) { | |
| conf[0][mode + 'EventListener'](conf[1], conf[2]); | |
| }); | |
| } | |
| // add event listeners | |
| bindEvents('add'); | |
| // expose public API | |
| this.destroy = bindEvents.bind(null, 'remove'); | |
| this.openURL = function(url) { | |
| // it can take a while for the dialog to appear | |
| var dialogTimeout = 500; | |
| setTimeout(function() { | |
| if (hasFocus && options.onIgnored) { | |
| options.onIgnored(); | |
| } | |
| }, dialogTimeout); | |
| window.location = url; | |
| }; | |
| } | |
| /* usage */ | |
| var url = 'fb://profile/240995729348595'; | |
| var badURL = 'lksadjgajsdhfaskd://slkdfs'; | |
| var linker = new DeepLinker({ | |
| onIgnored: function() { | |
| console.log('browser failed to respond to the deep link'); | |
| }, | |
| onFallback: function() { | |
| console.log('dialog hidden or user returned to tab'); | |
| }, | |
| onReturn: function() { | |
| console.log('user returned to the page from the native app'); | |
| }, | |
| }); | |
| linker.openURL(url); |
Author
You may be interested in this comment. Universal Links are a preferred pattern for IOS and apple is deprioritising the Custom URL schemes. Every year the levers are being tightened and Apple considers the custom URlL scheme as a security risk.
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Can it be fixed?