The Missing Manual
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Ext JS From Zero

Learn the config-driven enterprise JavaScript framework that thousands of internal apps still run on — and that almost nobody documents well: the class system, components and the containment tree, layouts, the data package (Model/Store/proxy/reader), the Grid and forms, MVVM with ViewControllers and ViewModels and binding, and Sencha Cmd. The magic, made explainable — especially if you got thrown into a legacy Ext JS codebase with no map.

  1. What Ext JS Even Is Ext JS describes a UI as a tree of config objects and the framework builds it. Meet components, containment, xtype, the Classic vs Modern toolkits, and why it feels nothing like React.
  2. The Class System Ext JS has its own class system, built before ES2015. Learn Ext.define, extend and callParent, the config-block getters/setters, xtype vs Ext.create, requires, and mixins.
  3. Components & the Containment Tree Every visible thing in Ext JS is a component, components nest inside containers via items, and you find them by reference and component query — never by global id.
  4. Layouts: How Things Get Positioned In Ext JS the parent container's layout sizes and positions its children — not CSS. Meet fit, hbox/vbox, border, and card, and learn why 'nothing shows up' is a layout bug.
  5. The Data Package How server data reaches the screen in Ext JS: Model defines a record's shape, Store holds the collection, a proxy fetches and saves it, and a reader parses the response.
  6. The Grid & Forms The Grid is a store rendered as rows; the form is fields over one record. Build a users grid with columns and renderers, add editing plugins and paging, then wire a form to edit the selected row.
  7. MVVM: ViewControllers, ViewModels & Binding Modern Ext JS splits a view into a ViewController (its behavior), a ViewModel (its data), and bind (the wire between them) — plus formulas and the legacy MVC controllers you'll still meet in old code.
  8. Sencha Cmd, Theming & Surviving a Legacy Codebase The build tool that confuses everyone (Sencha Cmd + app.json), SASS theming in a sentence, a practical survival kit for legacy Ext JS, an honest look at where the framework sits, and where to go next.