This is because as soon as your activity goes into the background, your app process can be stopped if the device is running low on memory. If you want the user to be able to put the app into the background and then come back three hours later to the exact same state, you should also persist data. Once the associated UI Controller (fragment/activity) is destroyed or the process is stopped, the ViewModel and all the contained data gets marked for garbage collection.ĭata used over multiple runs of the application should be persisted like normal in a local database, Shared Preferences, and/or in the cloud. ViewModels hold transient data used in the UI but they don’t persist data. Note that the section “How do I use ViewModels to save and restore UI state efficiently?” has an update at the top for the ViewModel Saved State module currently in alpha. UPDATED for the new ViewModel Saved State module. Yes, ViewModels used in conjunction with a few other classes can replace Loaders. Are ViewModels a replacement for Loaders? TL DR.UPDATED : How do I use ViewModels to save and restore UI state efficiently? T̶L̶ ̶D̶R̶ ̶Y̶o̶u̶ ̶u̶s̶e̶ ̶a̶ ̶c̶o̶m̶b̶i̶n̶a̶t̶i̶o̶n̶ ̶o̶f̶ ̶V̶i̶e̶w̶M̶o̶d̶e̶l̶s̶,̶ ̶o̶n̶S̶a̶v̶e̶I̶n̶s̶t̶a̶n̶c̶e̶S̶t̶a̶t̶e̶(̶)̶ ̶a̶n̶d̶ ̶l̶o̶c̶a̶l̶ ̶p̶e̶r̶s̶i̶s̶t̶e̶n̶c̶e̶.̶ TL DR You use ViewModels and the ViewModel Saved State module alongside local persistence.Are ViewModels a replacement for onSaveInstanceState ? TL DR No, but they are related so keep reading.Do ViewModels persist my data? TL DR No.ViewModels allow data to survive configuration changes such as screen rotations.Īt this point, you might have a few questions about the breadth of what ViewModels do. ViewModels are designed to hold and manage UI-related data in a life-cycle conscious way. In the last blog post I explored a simple use case with the new ViewModel class for saving basketball score data during a configuration change. ViewModels: Persistence, onSaveInstanceState(), Restoring UI State and Loaders Introduction How To Easily Enable GZIP Compression For Your Website.You can find several great BBedit GREP cheatsheets online with advanced search and replace examples. Need to search text files for mentions of specific words or phrases? This example searches US President Abraham Lincoln’s famous Gettysburg Address for the words nation, liberty and equality.Įgrep 'nation|liberty|equality' Advanced BBEdit GREP This GREP command will remove all whitespace from the beginning of lines. Removing WhitespaceĪnother annoying issue for most programmers is white space. The useful things that you can do with GREP are endless. You could run a single GREP that replaces all different font sizes all at once with one size, 7.0pt. Let’s say for example you have an HTML file with multiple font sizes and you want to make them all the same. The wildcard character combination (.*) will replace anything in its spot. GREP is the perfect tool to clean up Word’s mess. ![]() ![]() Word will create 580+ lines of code before it gets to your first paragraph tag. The “Save as Web Page” feature in Microsoft Word creates a lot of junk code. GREP stands for “Global regular expression print”. GREP allows you to quickly run complex find and replace commands that remove or leave characters. Thompson also designed the Unix operating system, the UTF-8 character encoding for the world wide web, as well as several operating systems and programming languages. It was created by legendary programmer Ken Thompson in 1974. This article will help you get started with BBEdit GREP advanced find and replace functions and point you in the right direction in case you have more advanced questions. But one of the least understood features of BBEdit is its GREP advanced find and replace function. Since its debut on April 1992, BBEdit has been a staple of power Macintosh users everywhere. BTW I’ve opened 200MB+ text files with BBEdit without a problem. Bare Bones Software, the company behind BBEdit (and it’s now defunct, sibling TextWrangler) wanted to create a simple but very powerful barebones text editing app. Anyone who does any coding or text editing in Mac OS X is probably familiar with BBEdit.
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