As the amount of records increases, the time required for the browser to render - * them increases. Paging is used to reduce the amount of data exchanged with the client. - * Note: if there are more records/rows than can be viewed in the available screen area, vertical - * scrollbars will be added.
- *Paging is typically handled on the server side (see exception below). The client sends - * parameters to the server side, which the server needs to interpret and then respond with the - * approprate data.
- *Ext.PagingToolbar is a specialized toolbar that is bound to a {@link Ext.data.Store} - * and provides automatic paging control. This Component {@link Ext.data.Store#load load}s blocks - * of data into the {@link #store} by passing {@link Ext.data.Store#paramNames paramNames} used for - * paging criteria.
- *PagingToolbar is typically used as one of the Grid's toolbars:
- *
-Ext.QuickTips.init(); // to display button quicktips
-
-var myStore = new Ext.data.Store({
- reader: new Ext.data.JsonReader({
- {@link Ext.data.JsonReader#totalProperty totalProperty}: 'results',
- ...
- }),
- ...
-});
-
-var myPageSize = 25; // server script should only send back 25 items at a time
-
-var grid = new Ext.grid.GridPanel({
- ...
- store: myStore,
- bbar: new Ext.PagingToolbar({
- {@link #store}: myStore, // grid and PagingToolbar using same store
- {@link #displayInfo}: true,
- {@link #pageSize}: myPageSize,
- {@link #prependButtons}: true,
- items: [
- 'text 1'
- ]
- })
-});
- * To use paging, pass the paging requirements to the server when the store is first loaded.
- *
-store.load({
- params: {
- // specify params for the first page load if using paging
- start: 0,
- limit: myPageSize,
- // other params
- foo: 'bar'
- }
-});
- * If using {@link Ext.data.Store#autoLoad store's autoLoad} configuration:
- *
-var myStore = new Ext.data.Store({
- {@link Ext.data.Store#autoLoad autoLoad}: {params:{start: 0, limit: 25}},
- ...
-});
- * The packet sent back from the server would have this form:
- *
-{
- "success": true,
- "results": 2000,
- "rows": [ // *Note: this must be an Array
- { "id": 1, "name": "Bill", "occupation": "Gardener" },
- { "id": 2, "name": "Ben", "occupation": "Horticulturalist" },
- ...
- { "id": 25, "name": "Sue", "occupation": "Botanist" }
- ]
-}
- * Paging with Local Data
- *Paging can also be accomplished with local data using extensions:
- *Deprecated. paramNames should be set in the data store
- * (see {@link Ext.data.Store#paramNames}).
Object mapping of parameter names used for load calls, initially set to:
- *{start: 'start', limit: 'limit'}
- * @type Object
- * @property paramNames
- * @deprecated
- */
-
- /**
- * The number of records to display per page. See also {@link #cursor}.
- * @type Number
- * @property pageSize
- */
-
- /**
- * Indicator for the record position. This property might be used to get the active page
- * number for example:
- * // t is reference to the paging toolbar instance
- * var activePage = Math.ceil((t.cursor + t.pageSize) / t.pageSize);
- * total : Number activePage : Number pages : Number start : Number limit : Number (note: the names of the start and limit properties are determined - * by the store's {@link Ext.data.Store#paramNames paramNames} property.)
- *Parameters may be added as required in the event handler.
- */ - 'beforechange' - ); - this.on('afterlayout', this.onFirstLayout, this, {single: true}); - this.cursor = 0; - this.bindStore(this.store, true); - }, - - // private - onFirstLayout : function(){ - if(this.dsLoaded){ - this.onLoad.apply(this, this.dsLoaded); - } - }, - - // private - updateInfo : function(){ - if(this.displayItem){ - var count = this.store.getCount(); - var msg = count == 0 ? - this.emptyMsg : - String.format( - this.displayMsg, - this.cursor+1, this.cursor+count, this.store.getTotalCount() - ); - this.displayItem.setText(msg); - } - }, - - // private - onLoad : function(store, r, o){ - if(!this.rendered){ - this.dsLoaded = [store, r, o]; - return; - } - var p = this.getParams(); - this.cursor = (o.params && o.params[p.start]) ? o.params[p.start] : 0; - var d = this.getPageData(), ap = d.activePage, ps = d.pages; - - this.afterTextItem.setText(String.format(this.afterPageText, d.pages)); - this.inputItem.setValue(ap); - this.first.setDisabled(ap == 1); - this.prev.setDisabled(ap == 1); - this.next.setDisabled(ap == ps); - this.last.setDisabled(ap == ps); - this.refresh.enable(); - this.updateInfo(); - this.fireEvent('change', this, d); - }, - - // private - getPageData : function(){ - var total = this.store.getTotalCount(); - return { - total : total, - activePage : Math.ceil((this.cursor+this.pageSize)/this.pageSize), - pages : total < this.pageSize ? 1 : Math.ceil(total/this.pageSize) - }; - }, - - /** - * Change the active page - * @param {Integer} page The page to display - */ - changePage : function(page){ - this.doLoad(((page-1) * this.pageSize).constrain(0, this.store.getTotalCount())); - }, - - // private - onLoadError : function(){ - if(!this.rendered){ - return; - } - this.refresh.enable(); - }, - - // private - readPage : function(d){ - var v = this.inputItem.getValue(), pageNum; - if (!v || isNaN(pageNum = parseInt(v, 10))) { - this.inputItem.setValue(d.activePage); - return false; - } - return pageNum; - }, - - onPagingFocus : function(){ - this.inputItem.select(); - }, - - //private - onPagingBlur : function(e){ - this.inputItem.setValue(this.getPageData().activePage); - }, - - // private - onPagingKeyDown : function(field, e){ - var k = e.getKey(), d = this.getPageData(), pageNum; - if (k == e.RETURN) { - e.stopEvent(); - pageNum = this.readPage(d); - if(pageNum !== false){ - pageNum = Math.min(Math.max(1, pageNum), d.pages) - 1; - this.doLoad(pageNum * this.pageSize); - } - }else if (k == e.HOME || k == e.END){ - e.stopEvent(); - pageNum = k == e.HOME ? 1 : d.pages; - field.setValue(pageNum); - }else if (k == e.UP || k == e.PAGEUP || k == e.DOWN || k == e.PAGEDOWN){ - e.stopEvent(); - if((pageNum = this.readPage(d))){ - var increment = e.shiftKey ? 10 : 1; - if(k == e.DOWN || k == e.PAGEDOWN){ - increment *= -1; - } - pageNum += increment; - if(pageNum >= 1 & pageNum <= d.pages){ - field.setValue(pageNum); - } - } - } - }, - - // private - getParams : function(){ - //retain backwards compat, allow params on the toolbar itself, if they exist. - return this.paramNames || this.store.paramNames; - }, - - // private - beforeLoad : function(){ - if(this.rendered && this.refresh){ - this.refresh.disable(); - } - }, - - // private - doLoad : function(start){ - var o = {}, pn = this.getParams(); - o[pn.start] = start; - o[pn.limit] = this.pageSize; - if(this.fireEvent('beforechange', this, o) !== false){ - this.store.load({params:o}); - } - }, - - /** - * Move to the first page, has the same effect as clicking the 'first' button. - */ - moveFirst : function(){ - this.doLoad(0); - }, - - /** - * Move to the previous page, has the same effect as clicking the 'previous' button. - */ - movePrevious : function(){ - this.doLoad(Math.max(0, this.cursor-this.pageSize)); - }, - - /** - * Move to the next page, has the same effect as clicking the 'next' button. - */ - moveNext : function(){ - this.doLoad(this.cursor+this.pageSize); - }, - - /** - * Move to the last page, has the same effect as clicking the 'last' button. - */ - moveLast : function(){ - var total = this.store.getTotalCount(), - extra = total % this.pageSize; - - this.doLoad(extra ? (total - extra) : total - this.pageSize); - }, - - /** - * Refresh the current page, has the same effect as clicking the 'refresh' button. - */ - doRefresh : function(){ - this.doLoad(this.cursor); - }, - - /** - * Binds the paging toolbar to the specified {@link Ext.data.Store} - * @param {Store} store The store to bind to this toolbar - * @param {Boolean} initial (Optional) true to not remove listeners - */ - bindStore : function(store, initial){ - var doLoad; - if(!initial && this.store){ - if(store !== this.store && this.store.autoDestroy){ - this.store.destroy(); - }else{ - this.store.un('beforeload', this.beforeLoad, this); - this.store.un('load', this.onLoad, this); - this.store.un('exception', this.onLoadError, this); - } - if(!store){ - this.store = null; - } - } - if(store){ - store = Ext.StoreMgr.lookup(store); - store.on({ - scope: this, - beforeload: this.beforeLoad, - load: this.onLoad, - exception: this.onLoadError - }); - doLoad = true; - } - this.store = store; - if(doLoad){ - this.onLoad(store, null, {}); - } - }, - - /** - * Unbinds the paging toolbar from the specified {@link Ext.data.Store} (deprecated) - * @param {Ext.data.Store} store The data store to unbind - */ - unbind : function(store){ - this.bindStore(null); - }, - - /** - * Binds the paging toolbar to the specified {@link Ext.data.Store} (deprecated) - * @param {Ext.data.Store} store The data store to bind - */ - bind : function(store){ - this.bindStore(store); - }, - - // private - onDestroy : function(){ - this.bindStore(null); - Ext.PagingToolbar.superclass.onDestroy.call(this); - } -}); - -})(); -Ext.reg('paging', Ext.PagingToolbar); \ No newline at end of file