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  • Help with Nicedit - removeFormat function

    - by Franck
    Hello, I'm trying to get around Nicedit, and especially the "removeFormat" function. The problem is I cannot find the "removeFormat" method source code in the code below. The JS syntax looks strange to me. Can someone help me ? /* NicEdit - Micro Inline WYSIWYG * Copyright 2007-2008 Brian Kirchoff * * NicEdit is distributed under the terms of the MIT license * For more information visit http://nicedit.com/ * Do not remove this copyright message */ var bkExtend = function(){ var A = arguments; if (A.length == 1) { A = [this, A[0]] } for (var B in A[1]) { A[0][B] = A[1][B] } return A[0] }; function bkClass(){ } bkClass.prototype.construct = function(){ }; bkClass.extend = function(C){ var A = function(){ if (arguments[0] !== bkClass) { return this.construct.apply(this, arguments) } }; var B = new this(bkClass); bkExtend(B, C); A.prototype = B; A.extend = this.extend; return A }; var bkElement = bkClass.extend({ construct: function(B, A){ if (typeof(B) == "string") { B = (A || document).createElement(B) } B = $BK(B); return B }, appendTo: function(A){ A.appendChild(this); return this }, appendBefore: function(A){ A.parentNode.insertBefore(this, A); return this }, addEvent: function(B, A){ bkLib.addEvent(this, B, A); return this }, setContent: function(A){ this.innerHTML = A; return this }, pos: function(){ var C = curtop = 0; var B = obj = this; if (obj.offsetParent) { do { C += obj.offsetLeft; curtop += obj.offsetTop } while (obj = obj.offsetParent) } var A = (!window.opera) ? parseInt(this.getStyle("border-width") || this.style.border) || 0 : 0; return [C + A, curtop + A + this.offsetHeight] }, noSelect: function(){ bkLib.noSelect(this); return this }, parentTag: function(A){ var B = this; do { if (B && B.nodeName && B.nodeName.toUpperCase() == A) { return B } B = B.parentNode } while (B); return false }, hasClass: function(A){ return this.className.match(new RegExp("(\s|^)nicEdit-" + A + "(\s|$)")) }, addClass: function(A){ if (!this.hasClass(A)) { this.className += " nicEdit-" + A } return this }, removeClass: function(A){ if (this.hasClass(A)) { this.className = this.className.replace(new RegExp("(\s|^)nicEdit-" + A + "(\s|$)"), " ") } return this }, setStyle: function(A){ var B = this.style; for (var C in A) { switch (C) { case "float": B.cssFloat = B.styleFloat = A[C]; break; case "opacity": B.opacity = A[C]; B.filter = "alpha(opacity=" + Math.round(A[C] * 100) + ")"; break; case "className": this.className = A[C]; break; default: B[C] = A[C] } } return this }, getStyle: function(A, C){ var B = (!C) ? document.defaultView : C; if (this.nodeType == 1) { return (B && B.getComputedStyle) ? B.getComputedStyle(this, null).getPropertyValue(A) : this.currentStyle[bkLib.camelize(A)] } }, remove: function(){ this.parentNode.removeChild(this); return this }, setAttributes: function(A){ for (var B in A) { this[B] = A[B] } return this } }); var bkLib = { isMSIE: (navigator.appVersion.indexOf("MSIE") != -1), addEvent: function(C, B, A){ (C.addEventListener) ? C.addEventListener(B, A, false) : C.attachEvent("on" + B, A) }, toArray: function(C){ var B = C.length, A = new Array(B); while (B--) { A[B] = C[B] } return A }, noSelect: function(B){ if (B.setAttribute && B.nodeName.toLowerCase() != "input" && B.nodeName.toLowerCase() != "textarea") { B.setAttribute("unselectable", "on") } for (var A = 0; A < B.childNodes.length; A++) { bkLib.noSelect(B.childNodes[A]) } }, camelize: function(A){ return A.replace(/-(.)/g, function(B, C){ return C.toUpperCase() }) }, inArray: function(A, B){ return (bkLib.search(A, B) != null) }, search: function(A, C){ for (var B = 0; B < A.length; B++) { if (A[B] == C) { return B } } return null }, cancelEvent: function(A){ A = A || window.event; if (A.preventDefault && A.stopPropagation) { A.preventDefault(); A.stopPropagation() } return false }, domLoad: [], domLoaded: function(){ if (arguments.callee.done) { return } arguments.callee.done = true; for (i = 0; i < bkLib.domLoad.length; i++) { bkLib.domLoadi } }, onDomLoaded: function(A){ this.domLoad.push(A); if (document.addEventListener) { document.addEventListener("DOMContentLoaded", bkLib.domLoaded, null) } else { if (bkLib.isMSIE) { document.write(".nicEdit-main p { margin: 0; }<\/script"); $BK("__ie_onload").onreadystatechange = function(){ if (this.readyState == "complete") { bkLib.domLoaded() } } } } window.onload = bkLib.domLoaded } }; function $BK(A){ if (typeof(A) == "string") { A = document.getElementById(A) } return (A && !A.appendTo) ? bkExtend(A, bkElement.prototype) : A } var bkEvent = { addEvent: function(A, B){ if (B) { this.eventList = this.eventList || {}; this.eventList[A] = this.eventList[A] || []; this.eventList[A].push(B) } return this }, fireEvent: function(){ var A = bkLib.toArray(arguments), C = A.shift(); if (this.eventList && this.eventList[C]) { for (var B = 0; B < this.eventList[C].length; B++) { this.eventList[C][B].apply(this, A) } } } }; function __(A){ return A } Function.prototype.closure = function(){ var A = this, B = bkLib.toArray(arguments), C = B.shift(); return function(){ if (typeof(bkLib) != "undefined") { return A.apply(C, B.concat(bkLib.toArray(arguments))) } } }; Function.prototype.closureListener = function(){ var A = this, C = bkLib.toArray(arguments), B = C.shift(); return function(E){ E = E || window.event; if (E.target) { var D = E.target } else { var D = E.srcElement } return A.apply(B, [E, D].concat(C)) } }; var nicEditorConfig = bkClass.extend({ buttons: { 'bold': { name: _('Mettre en gras'), command: 'Bold', tags: ['B', 'STRONG'], css: { 'font-weight': 'bold' }, key: 'b' }, 'italic': { name: _('Mettre en italique'), command: 'Italic', tags: ['EM', 'I'], css: { 'font-style': 'italic' }, key: 'i' }, 'underline': { name: _('Souligner'), command: 'Underline', tags: ['U'], css: { 'text-decoration': 'underline' }, key: 'u' }, 'left': { name: _('Aligné à gauche'), command: 'justifyleft', noActive: true }, 'center': { name: _('Centré'), command: 'justifycenter', noActive: true }, 'right': { name: _('Aligné à droite'), command: 'justifyright', noActive: true }, 'justify': { name: _('Justifié'), command: 'justifyfull', noActive: true }, 'ol': { name: _('Liste non ordonnée'), command: 'insertorderedlist', tags: ['OL'] }, 'ul': { name: _('Liste non ordonnée'), command: 'insertunorderedlist', tags: ['UL'] }, 'subscript': { name: _('Placer en indice'), command: 'subscript', tags: ['SUB'] }, 'superscript': { name: _('Placer en exposant'), command: 'superscript', tags: ['SUP'] }, 'strikethrough': { name: _('Barrer le texte'), command: 'strikeThrough', css: { 'text-decoration': 'line-through' } }, 'removeformat': { name: _('Supprimer la mise en forme'), command: 'removeformat', noActive: true }, 'indent': { name: _('Indenter'), command: 'indent', noActive: true }, 'outdent': { name: _('Remove Indent'), command: 'outdent', noActive: true }, 'hr': { name: _('Ligne horizontale'), command: 'insertHorizontalRule', noActive: true } }, iconsPath: 'http://js.nicedit.com/nicEditIcons-latest.gif', buttonList: ['save', 'bold', 'italic', 'underline', 'left', 'center', 'right', 'justify', 'ol', 'ul', 'fontSize', 'fontFamily', 'fontFormat', 'indent', 'outdent', 'image', 'upload', 'link', 'unlink', 'forecolor', 'bgcolor'], iconList: { "xhtml": 1, "bgcolor": 2, "forecolor": 3, "bold": 4, "center": 5, "hr": 6, "indent": 7, "italic": 8, "justify": 9, "left": 10, "ol": 11, "outdent": 12, "removeformat": 13, "right": 14, "save": 25, "strikethrough": 16, "subscript": 17, "superscript": 18, "ul": 19, "underline": 20, "image": 21, "link": 22, "unlink": 23, "close": 24, "arrow": 26, "upload": 27, "question":2 } }); ; var nicEditors = { nicPlugins: [], editors: [], registerPlugin: function(B, A){ this.nicPlugins.push({ p: B, o: A }) }, allTextAreas: function(C){ var A = document.getElementsByTagName("textarea"); for (var B = 0; B < A.length; B++) { nicEditors.editors.push(new nicEditor(C).panelInstance(A[B])) } return nicEditors.editors }, findEditor: function(C){ var B = nicEditors.editors; for (var A = 0; A < B.length; A++) { if (B[A].instanceById(C)) { return B[A].instanceById(C) } } } }; var nicEditor = bkClass.extend({ construct: function(C){ this.options = new nicEditorConfig(); bkExtend(this.options, C); this.nicInstances = new Array(); this.loadedPlugins = new Array(); var A = nicEditors.nicPlugins; for (var B = 0; B < A.length; B++) { this.loadedPlugins.push(new A[B].p(this, A[B].o)) } nicEditors.editors.push(this); bkLib.addEvent(document.body, "mousedown", this.selectCheck.closureListener(this)) }, panelInstance: function(B, C){ B = this.checkReplace($BK(B)); var A = new bkElement("DIV").setStyle({ width: (parseInt(B.getStyle("width")) || B.clientWidth) + "px" }).appendBefore(B); this.setPanel(A); return this.addInstance(B, C) }, checkReplace: function(B){ var A = nicEditors.findEditor(B); if (A) { A.removeInstance(B); A.removePanel() } return B }, addInstance: function(B, C){ B = this.checkReplace($BK(B)); if (B.contentEditable || !!window.opera) { var A = new nicEditorInstance(B, C, this) } else { var A = new nicEditorIFrameInstance(B, C, this) } this.nicInstances.push(A); return this }, removeInstance: function(C){ C = $BK(C); var B = this.nicInstances; for (var A = 0; A < B.length; A++) { if (B[A].e == C) { B[A].remove(); this.nicInstances.splice(A, 1) } } }, removePanel: function(A){ if (this.nicPanel) { this.nicPanel.remove(); this.nicPanel = null } }, instanceById: function(C){ C = $BK(C); var B = this.nicInstances; for (var A = 0; A < B.length; A++) { if (B[A].e == C) { return B[A] } } }, setPanel: function(A){ this.nicPanel = new nicEditorPanel($BK(A), this.options, this); this.fireEvent("panel", this.nicPanel); return this }, nicCommand: function(B, A){ if (this.selectedInstance) { this.selectedInstance.nicCommand(B, A) } }, getIcon: function(D, A){ var C = this.options.iconList[D]; var B = (A.iconFiles) ? A.iconFiles[D] : ""; return { backgroundImage: "url('" + ((C) ? this.options.iconsPath : B) + "')", backgroundPosition: ((C) ? ((C - 1) * -18) : 0) + "px 0px" } }, selectCheck: function(C, A){ var B = false; do { if (A.className && A.className.indexOf("nicEdit") != -1) { return false } } while (A = A.parentNode); this.fireEvent("blur", this.selectedInstance, A); this.lastSelectedInstance = this.selectedInstance; this.selectedInstance = null; return false } }); nicEditor = nicEditor.extend(bkEvent); var nicEditorInstance = bkClass.extend({ isSelected: false, construct: function(G, D, C){ this.ne = C; this.elm = this.e = G; this.options = D || {}; newX = parseInt(G.getStyle("width")) || G.clientWidth; newY = parseInt(G.getStyle("height")) || G.clientHeight; this.initialHeight = newY - 8; var H = (G.nodeName.toLowerCase() == "textarea"); if (H || this.options.hasPanel) { var B = (bkLib.isMSIE && !((typeof document.body.style.maxHeight != "undefined") && document.compatMode == "CSS1Compat")); var E = { width: newX + "px", border: "1px solid #ccc", borderTop: 0, overflowY: "auto", overflowX: "hidden" }; E[(B) ? "height" : "maxHeight"] = (this.ne.options.maxHeight) ? this.ne.options.maxHeight + "px" : null; this.editorContain = new bkElement("DIV").setStyle(E).appendBefore(G); var A = new bkElement("DIV").setStyle({ width: (newX - 8) + "px", margin: "4px", minHeight: newY + "px" }).addClass("main").appendTo(this.editorContain); G.setStyle({ display: "none" }); A.innerHTML = G.innerHTML; if (H) { A.setContent(G.value); this.copyElm = G; var F = G.parentTag("FORM"); if (F) { bkLib.addEvent(F, "submit", this.saveContent.closure(this)) } } A.setStyle((B) ? { height: newY + "px" } : { overflow: "hidden" }); this.elm = A } this.ne.addEvent("blur", this.blur.closure(this)); this.init(); this.blur() }, init: function(){ this.elm.setAttribute("contentEditable", "true"); if (this.getContent() == "") { this.setContent("") } this.instanceDoc = document.defaultView; this.elm.addEvent("mousedown", this.selected.closureListener(this)).addEvent("keypress", this.keyDown.closureListener(this)).addEvent("focus", this.selected.closure(this)).addEvent("blur", this.blur.closure(this)).addEvent("keyup", this.selected.closure(this)); this.elm.addEvent("resizestart",function(){return false}); this.elm.addEvent("dragstart",function(){return false}); this.ne.fireEvent("add", this); }, remove: function(){ this.saveContent(); if (this.copyElm || this.options.hasPanel) { this.editorContain.remove(); this.e.setStyle({ display: "block" }); this.ne.removePanel() } this.disable(); this.ne.fireEvent("remove", this) }, disable: function(){ this.elm.setAttribute("contentEditable", "false") }, getSel: function(){ return (window.getSelection) ? window.getSelection() : document.selection }, getRng: function(){ var A = this.getSel(); if (!A) { return null } return (A.rangeCount 0) ? A.getRangeAt(0) : A.createRange() }, selRng: function(A, B){ if (window.getSelection) { B.removeAllRanges(); B.addRange(A) } else { A.select() } }, selElm: function(){ var C = this.getRng(); if (C.startContainer) { var D = C.startContainer; if (C.cloneContents().childNodes.length == 1) { for (var B = 0; B < D.childNodes.length; B++) { var A = D.childNodes[B].ownerDocument.createRange(); A.selectNode(D.childNodes[B]); if (C.compareBoundaryPoints(Range.START_TO_START, A) != 1 && C.compareBoundaryPoints(Range.END_TO_END, A) != -1) { return $BK(D.childNodes[B]) } } } return $BK(D) } else { return $BK((this.getSel().type == "Control") ? C.item(0) : C.parentElement()) } }, saveRng: function(){ this.savedRange = this.getRng(); this.savedSel = this.getSel() }, restoreRng: function(){ if (this.savedRange) { this.selRng(this.savedRange, this.savedSel) } }, keyDown: function(B, A){ if (B.ctrlKey) { this.ne.fireEvent("key", this, B) } }, selected: function(C, A){ if (!A) { A = this.selElm() } if (!C.ctrlKey) { var B = this.ne.selectedInstance; if (B != this) { if (B) { this.ne.fireEvent("blur", B, A) } this.ne.selectedInstance = this; this.ne.fireEvent("focus", B, A) } this.ne.fireEvent("selected", B, A); this.isFocused = true; this.elm.addClass("selected") } return false }, blur: function(){ this.isFocused = false; this.elm.removeClass("selected") }, saveContent: function(){ if (this.copyElm || this.options.hasPanel) { this.ne.fireEvent("save", this); (this.copyElm) ? this.copyElm.value = this.getContent() : this.e.innerHTML = this.getContent() } }, getElm: function(){ return this.elm }, getContent: function(){ this.content = this.getElm().innerHTML; this.ne.fireEvent("get", this); return this.content }, setContent: function(A){ this.content = A; this.ne.fireEvent("set", this); this.elm.innerHTML = this.content }, nicCommand: function(B, A){ document.execCommand(B, false, A) } }); var nicEditorIFrameInstance = nicEditorInstance.extend({ savedStyles: [], init: function(){ var B = this.elm.innerHTML.replace(/^\s+|\s+$/g, ""); this.elm.innerHTML = ""; (!B) ? B = "" : B; this.initialContent = B; this.elmFrame = new bkElement("iframe").setAttributes({ src: "javascript:;", frameBorder: 0, allowTransparency: "true", scrolling: "no" }).setStyle({ height: "100px", width: "100%" }).addClass("frame").appendTo(this.elm); if (this.copyElm) { this.elmFrame.setStyle({ width: (this.elm.offsetWidth - 4) + "px" }) } var A = ["font-size", "font-family", "font-weight", "color"]; for (itm in A) { this.savedStyles[bkLib.camelize(itm)] = this.elm.getStyle(itm) } setTimeout(this.initFrame.closure(this), 50) }, disable: function(){ this.elm.innerHTML = this.getContent() }, initFrame: function(){ var B = $BK(this.elmFrame.contentWindow.document); B.designMode = "on"; B.open(); var A = this.ne.options.externalCSS; B.write("" + ((A) ? '' : "") + '' + this.initialContent + ""); B.close(); this.frameDoc = B; this.frameWin = $BK(this.elmFrame.contentWindow); this.frameContent = $BK(this.frameWin.document.body).setStyle(this.savedStyles); this.instanceDoc = this.frameWin.document.defaultView; this.heightUpdate(); this.frameDoc.addEvent("mousedown", this.selected.closureListener(this)).addEvent("keyup", this.heightUpdate.closureListener(this)).addEvent("keydown", this.keyDown.closureListener(this)).addEvent("keyup", this.selected.closure(this)); this.ne.fireEvent("add", this) }, getElm: function(){ return this.frameContent }, setContent: function(A){ this.content = A; this.ne.fireEvent("set", this); this.frameContent.innerHTML = this.content; this.heightUpdate() }, getSel: function(){ return (this.frameWin) ? this.frameWin.getSelection() : this.frameDoc.selection }, heightUpdate: function(){ this.elmFrame.style.height = Math.max(this.frameContent.offsetHeight, this.initialHeight) + "px" }, nicCommand: function(B, A){ this.frameDoc.execCommand(B, false, A); setTimeout(this.heightUpdate.closure(this), 100) } }); var nicEditorPanel = bkClass.extend({ construct: function(E, B, A){ this.elm = E; this.options = B; this.ne = A; this.panelButtons = new Array(); this.buttonList = bkExtend([], this.ne.options.buttonList); this.panelContain = new bkElement("DIV").setStyle({ overflow: "hidden", width: "100%", border: "1px solid #cccccc", backgroundColor: "#efefef" }).addClass("panelContain"); this.panelElm = new bkElement("DIV").setStyle({ margin: "2px", marginTop: "0px", zoom: 1, overflow: "hidden" }).addClass("panel").appendTo(this.panelContain); this.panelContain.appendTo(E); var C = this.ne.options; var D = C.buttons; for (button in D) { this.addButton(button, C, true) } this.reorder(); E.noSelect() }, addButton: function(buttonName, options, noOrder){ var button = options.buttons[buttonName]; var type = (button.type) ? eval("(typeof(" + button.type + ') == "undefined") ? null : ' + button.type + ";") : nicEditorButton; var hasButton = bkLib.inArray(this.buttonList, buttonName); if (type && (hasButton || this.ne.options.fullPanel)) { this.panelButtons.push(new type(this.panelElm, buttonName, options, this.ne)); if (!hasButton) { this.buttonList.push(buttonName) } } }, findButton: function(B){ for (var A = 0; A < this.panelButtons.length; A++) { if (this.panelButtons[A].name == B) { return this.panelButtons[A] } } }, reorder: function(){ var C = this.buttonList; for (var B = 0; B < C.length; B++) { var A = this.findButton(C[B]); if (A) { this.panelElm.appendChild(A.margin) } } }, remove: function(){ this.elm.remove() } }); var nicEditorButton = bkClass.extend({ construct: function(D, A, C, B){ this.options = C.buttons[A]; this.name = A; this.ne = B; this.elm = D; this.margin = new bkElement("DIV").setStyle({ "float": "left", marginTop: "2px" }).appendTo(D); this.contain = new bkElement("DIV").setStyle({ width: "20px", height: "20px" }).addClass("buttonContain").appendTo(this.margin); this.border = new bkElement("DIV").setStyle({ backgroundColor: "#efefef", border: "1px solid #efefef" }).appendTo(this.contain); this.button = new bkElement("DIV").setStyle({ width: "18px", height: "18px", overflow: "hidden", zoom: 1, cursor: "pointer" }).addClass("button").setStyle(this.ne.getIcon(A, C)).appendTo(this.border); this.button.addEvent("mouseover", this.hoverOn.closure(this)).addEvent("mouseout", this.hoverOff.closure(this)).addEvent("mousedown", this.mouseClick.closure(this)).noSelect(); if (!window.opera) { this.button.onmousedown = this.button.onclick = bkLib.cancelEvent } B.addEvent("selected", this.enable.closure(this)).addEvent("blur", this.disable.closure(this)).addEvent("key", this.key.closure(this)); this.disable(); this.init() }, init: function(){ }, hide: function(){ this.contain.setStyle({ display: "none" }) }, updateState: function(){ if (this.isDisabled) { this.setBg() } else { if (this.isHover) { this.setBg("hover") } else { if (this.isActive) { this.setBg("active") } else { this.setBg() } } } }, setBg: function(A){ switch (A) { case "hover": var B = { border: "1px solid #666", backgroundColor: "#ddd" }; break; case "active": var B = { border: "1px solid #666", backgroundColor: "#ccc" }; break; default: var B = { border: "1px solid #efefef", backgroundColor: "#efefef" } } this.border.setStyle(B).addClass("button-" + A) }, checkNodes: function(A){ var B = A; do { if (this.options.tags && bkLib.inArray(this.options.tags, B.nodeName)) { this.activate(); return true } } while (B = B.parentNode && B.className != "nicEdit"); B = $BK(A); while (B.nodeType == 3) { B = $BK(B.parentNode) } if (this.options.css) { for (itm in this.options.css) { if (B.getStyle(itm, this.ne.selectedInstance.instanceDoc) == this.options.css[itm]) { this.activate(); return true } } } this.deactivate(); return false }, activate: function(){ if (!this.isDisabled) { this.isActive = true; this.updateState(); this.ne.fireEvent("buttonActivate", this) } }, deactivate: function(){ this.isActive = false; this.updateState(); if (!this.isDisabled) { th

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  • problem with google chrome

    - by user365559
    hi. i have javscript file for history management.IT is not supported by chrome when i am trying to navigate to back page with backbutton in the browser.I can see the url change but it doesnt go to preceeding page. BrowserHistoryUtils = { addEvent: function(elm, evType, fn, useCapture) { useCapture = useCapture || false; if (elm.addEventListener) { elm.addEventListener(evType, fn, useCapture); return true; } else if (elm.attachEvent) { var r = elm.attachEvent('on' + evType, fn); return r; } else { elm['on' + evType] = fn; } } } BrowserHistory = (function() { // type of browser var browser = { ie: false, firefox: false, safari: false, opera: false, version: -1 }; // if setDefaultURL has been called, our first clue // that the SWF is ready and listening //var swfReady = false; // the URL we'll send to the SWF once it is ready //var pendingURL = ''; // Default app state URL to use when no fragment ID present var defaultHash = ''; // Last-known app state URL var currentHref = document.location.href; // Initial URL (used only by IE) var initialHref = document.location.href; // Initial URL (used only by IE) var initialHash = document.location.hash; // History frame source URL prefix (used only by IE) var historyFrameSourcePrefix = 'history/historyFrame.html?'; // History maintenance (used only by Safari) var currentHistoryLength = -1; var historyHash = []; var initialState = createState(initialHref, initialHref + '#' + initialHash, initialHash); var backStack = []; var forwardStack = []; var currentObjectId = null; //UserAgent detection var useragent = navigator.userAgent.toLowerCase(); if (useragent.indexOf("opera") != -1) { browser.opera = true; } else if (useragent.indexOf("msie") != -1) { browser.ie = true; browser.version = parseFloat(useragent.substring(useragent.indexOf('msie') + 4)); } else if (useragent.indexOf("safari") != -1) { browser.safari = true; browser.version = parseFloat(useragent.substring(useragent.indexOf('safari') + 7)); } else if (useragent.indexOf("gecko") != -1) { browser.firefox = true; } if (browser.ie == true && browser.version == 7) { window["_ie_firstload"] = false; } // Accessor functions for obtaining specific elements of the page. function getHistoryFrame() { return document.getElementById('ie_historyFrame'); } function getAnchorElement() { return document.getElementById('firefox_anchorDiv'); } function getFormElement() { return document.getElementById('safari_formDiv'); } function getRememberElement() { return document.getElementById("safari_remember_field"); } // Get the Flash player object for performing ExternalInterface callbacks. // Updated for changes to SWFObject2. function getPlayer(id) { if (id && document.getElementById(id)) { var r = document.getElementById(id); if (typeof r.SetVariable != "undefined") { return r; } else { var o = r.getElementsByTagName("object"); var e = r.getElementsByTagName("embed"); if (o.length > 0 && typeof o[0].SetVariable != "undefined") { return o[0]; } else if (e.length > 0 && typeof e[0].SetVariable != "undefined") { return e[0]; } } } else { var o = document.getElementsByTagName("object"); var e = document.getElementsByTagName("embed"); if (e.length > 0 && typeof e[0].SetVariable != "undefined") { return e[0]; } else if (o.length > 0 && typeof o[0].SetVariable != "undefined") { return o[0]; } else if (o.length > 1 && typeof o[1].SetVariable != "undefined") { return o[1]; } } return undefined; } function getPlayers() { var players = []; if (players.length == 0) { var tmp = document.getElementsByTagName('object'); players = tmp; } if (players.length == 0 || players[0].object == null) { var tmp = document.getElementsByTagName('embed'); players = tmp; } return players; } function getIframeHash() { var doc = getHistoryFrame().contentWindow.document; var hash = String(doc.location.search); if (hash.length == 1 && hash.charAt(0) == "?") { hash = ""; } else if (hash.length >= 2 && hash.charAt(0) == "?") { hash = hash.substring(1); } return hash; } /* Get the current location hash excluding the '#' symbol. */ function getHash() { // It would be nice if we could use document.location.hash here, // but it's faulty sometimes. var idx = document.location.href.indexOf('#'); return (idx >= 0) ? document.location.href.substr(idx+1) : ''; } /* Get the current location hash excluding the '#' symbol. */ function setHash(hash) { // It would be nice if we could use document.location.hash here, // but it's faulty sometimes. if (hash == '') hash = '#' document.location.hash = hash; } function createState(baseUrl, newUrl, flexAppUrl) { return { 'baseUrl': baseUrl, 'newUrl': newUrl, 'flexAppUrl': flexAppUrl, 'title': null }; } /* Add a history entry to the browser. * baseUrl: the portion of the location prior to the '#' * newUrl: the entire new URL, including '#' and following fragment * flexAppUrl: the portion of the location following the '#' only */ function addHistoryEntry(baseUrl, newUrl, flexAppUrl) { //delete all the history entries forwardStack = []; if (browser.ie) { //Check to see if we are being asked to do a navigate for the first //history entry, and if so ignore, because it's coming from the creation //of the history iframe if (flexAppUrl == defaultHash && document.location.href == initialHref && window['_ie_firstload']) { currentHref = initialHref; return; } if ((!flexAppUrl || flexAppUrl == defaultHash) && window['_ie_firstload']) { newUrl = baseUrl + '#' + defaultHash; flexAppUrl = defaultHash; } else { // for IE, tell the history frame to go somewhere without a '#' // in order to get this entry into the browser history. getHistoryFrame().src = historyFrameSourcePrefix + flexAppUrl; } setHash(flexAppUrl); } else { //ADR if (backStack.length == 0 && initialState.flexAppUrl == flexAppUrl) { initialState = createState(baseUrl, newUrl, flexAppUrl); } else if(backStack.length > 0 && backStack[backStack.length - 1].flexAppUrl == flexAppUrl) { backStack[backStack.length - 1] = createState(baseUrl, newUrl, flexAppUrl); } if (browser.safari) { // for Safari, submit a form whose action points to the desired URL if (browser.version <= 419.3) { var file = window.location.pathname.toString(); file = file.substring(file.lastIndexOf("/")+1); getFormElement().innerHTML = '<form name="historyForm" action="'+file+'#' + flexAppUrl + '" method="GET"></form>'; //get the current elements and add them to the form var qs = window.location.search.substring(1); var qs_arr = qs.split("&"); for (var i = 0; i < qs_arr.length; i++) { var tmp = qs_arr[i].split("="); var elem = document.createElement("input"); elem.type = "hidden"; elem.name = tmp[0]; elem.value = tmp[1]; document.forms.historyForm.appendChild(elem); } document.forms.historyForm.submit(); } else { top.location.hash = flexAppUrl; } // We also have to maintain the history by hand for Safari historyHash[history.length] = flexAppUrl; _storeStates(); } else { // Otherwise, write an anchor into the page and tell the browser to go there addAnchor(flexAppUrl); setHash(flexAppUrl); } } backStack.push(createState(baseUrl, newUrl, flexAppUrl)); } function _storeStates() { if (browser.safari) { getRememberElement().value = historyHash.join(","); } } function handleBackButton() { //The "current" page is always at the top of the history stack. var current = backStack.pop(); if (!current) { return; } var last = backStack[backStack.length - 1]; if (!last && backStack.length == 0){ last = initialState; } forwardStack.push(current); } function handleForwardButton() { //summary: private method. Do not call this directly. var last = forwardStack.pop(); if (!last) { return; } backStack.push(last); } function handleArbitraryUrl() { //delete all the history entries forwardStack = []; } /* Called periodically to poll to see if we need to detect navigation that has occurred */ function checkForUrlChange() { if (browser.ie) { if (currentHref != document.location.href && currentHref + '#' != document.location.href) { //This occurs when the user has navigated to a specific URL //within the app, and didn't use browser back/forward //IE seems to have a bug where it stops updating the URL it //shows the end-user at this point, but programatically it //appears to be correct. Do a full app reload to get around //this issue. if (browser.version < 7) { currentHref = document.location.href; document.location.reload(); } else { if (getHash() != getIframeHash()) { // this.iframe.src = this.blankURL + hash; var sourceToSet = historyFrameSourcePrefix + getHash(); getHistoryFrame().src = sourceToSet; } } } } if (browser.safari) { // For Safari, we have to check to see if history.length changed. if (currentHistoryLength >= 0 && history.length != currentHistoryLength) { //alert("did change: " + history.length + ", " + historyHash.length + "|" + historyHash[history.length] + "|>" + historyHash.join("|")); // If it did change, then we have to look the old state up // in our hand-maintained array since document.location.hash // won't have changed, then call back into BrowserManager. currentHistoryLength = history.length; var flexAppUrl = historyHash[currentHistoryLength]; if (flexAppUrl == '') { //flexAppUrl = defaultHash; } //ADR: to fix multiple if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { pl[i].browserURLChange(flexAppUrl); } } else { getPlayer().browserURLChange(flexAppUrl); } _storeStates(); } } if (browser.firefox) { if (currentHref != document.location.href) { var bsl = backStack.length; var urlActions = { back: false, forward: false, set: false } if ((window.location.hash == initialHash || window.location.href == initialHref) && (bsl == 1)) { urlActions.back = true; // FIXME: could this ever be a forward button? // we can't clear it because we still need to check for forwards. Ugg. // clearInterval(this.locationTimer); handleBackButton(); } // first check to see if we could have gone forward. We always halt on // a no-hash item. if (forwardStack.length > 0) { if (forwardStack[forwardStack.length-1].flexAppUrl == getHash()) { urlActions.forward = true; handleForwardButton(); } } // ok, that didn't work, try someplace back in the history stack if ((bsl >= 2) && (backStack[bsl - 2])) { if (backStack[bsl - 2].flexAppUrl == getHash()) { urlActions.back = true; handleBackButton(); } } if (!urlActions.back && !urlActions.forward) { var foundInStacks = { back: -1, forward: -1 } for (var i = 0; i < backStack.length; i++) { if (backStack[i].flexAppUrl == getHash() && i != (bsl - 2)) { arbitraryUrl = true; foundInStacks.back = i; } } for (var i = 0; i < forwardStack.length; i++) { if (forwardStack[i].flexAppUrl == getHash() && i != (bsl - 2)) { arbitraryUrl = true; foundInStacks.forward = i; } } handleArbitraryUrl(); } // Firefox changed; do a callback into BrowserManager to tell it. currentHref = document.location.href; var flexAppUrl = getHash(); if (flexAppUrl == '') { //flexAppUrl = defaultHash; } //ADR: to fix multiple if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { pl[i].browserURLChange(flexAppUrl); } } else { getPlayer().browserURLChange(flexAppUrl); } } } //setTimeout(checkForUrlChange, 50); } /* Write an anchor into the page to legitimize it as a URL for Firefox et al. */ function addAnchor(flexAppUrl) { if (document.getElementsByName(flexAppUrl).length == 0) { getAnchorElement().innerHTML += "<a name='" + flexAppUrl + "'>" + flexAppUrl + "</a>"; } } var _initialize = function () { if (browser.ie) { var scripts = document.getElementsByTagName('script'); for (var i = 0, s; s = scripts[i]; i++) { if (s.src.indexOf("history.js") > -1) { var iframe_location = (new String(s.src)).replace("history.js", "historyFrame.html"); } } historyFrameSourcePrefix = iframe_location + "?"; var src = historyFrameSourcePrefix; var iframe = document.createElement("iframe"); iframe.id = 'ie_historyFrame'; iframe.name = 'ie_historyFrame'; //iframe.src = historyFrameSourcePrefix; try { document.body.appendChild(iframe); } catch(e) { setTimeout(function() { document.body.appendChild(iframe); }, 0); } } if (browser.safari) { var rememberDiv = document.createElement("div"); rememberDiv.id = 'safari_rememberDiv'; document.body.appendChild(rememberDiv); rememberDiv.innerHTML = '<input type="text" id="safari_remember_field" style="width: 500px;">'; var formDiv = document.createElement("div"); formDiv.id = 'safari_formDiv'; document.body.appendChild(formDiv); var reloader_content = document.createElement('div'); reloader_content.id = 'safarireloader'; var scripts = document.getElementsByTagName('script'); for (var i = 0, s; s = scripts[i]; i++) { if (s.src.indexOf("history.js") > -1) { html = (new String(s.src)).replace(".js", ".html"); } } reloader_content.innerHTML = '<iframe id="safarireloader-iframe" src="about:blank" frameborder="no" scrolling="no"></iframe>'; document.body.appendChild(reloader_content); reloader_content.style.position = 'absolute'; reloader_content.style.left = reloader_content.style.top = '-9999px'; iframe = reloader_content.getElementsByTagName('iframe')[0]; if (document.getElementById("safari_remember_field").value != "" ) { historyHash = document.getElementById("safari_remember_field").value.split(","); } } if (browser.firefox) { var anchorDiv = document.createElement("div"); anchorDiv.id = 'firefox_anchorDiv'; document.body.appendChild(anchorDiv); } //setTimeout(checkForUrlChange, 50); } return { historyHash: historyHash, backStack: function() { return backStack; }, forwardStack: function() { return forwardStack }, getPlayer: getPlayer, initialize: function(src) { _initialize(src); }, setURL: function(url) { document.location.href = url; }, getURL: function() { return document.location.href; }, getTitle: function() { return document.title; }, setTitle: function(title) { try { backStack[backStack.length - 1].title = title; } catch(e) { } //if on safari, set the title to be the empty string. if (browser.safari) { if (title == "") { try { var tmp = window.location.href.toString(); title = tmp.substring((tmp.lastIndexOf("/")+1), tmp.lastIndexOf("#")); } catch(e) { title = ""; } } } document.title = title; }, setDefaultURL: function(def) { defaultHash = def; def = getHash(); //trailing ? is important else an extra frame gets added to the history //when navigating back to the first page. Alternatively could check //in history frame navigation to compare # and ?. if (browser.ie) { window['_ie_firstload'] = true; var sourceToSet = historyFrameSourcePrefix + def; var func = function() { getHistoryFrame().src = sourceToSet; window.location.replace("#" + def); setInterval(checkForUrlChange, 50); } try { func(); } catch(e) { window.setTimeout(function() { func(); }, 0); } } if (browser.safari) { currentHistoryLength = history.length; if (historyHash.length == 0) { historyHash[currentHistoryLength] = def; var newloc = "#" + def; window.location.replace(newloc); } else { //alert(historyHash[historyHash.length-1]); } //setHash(def); setInterval(checkForUrlChange, 50); } if (browser.firefox || browser.opera) { var reg = new RegExp("#" + def + "$"); if (window.location.toString().match(reg)) { } else { var newloc ="#" + def; window.location.replace(newloc); } setInterval(checkForUrlChange, 50); //setHash(def); } }, /* Set the current browser URL; called from inside BrowserManager to propagate * the application state out to the container. */ setBrowserURL: function(flexAppUrl, objectId) { if (browser.ie && typeof objectId != "undefined") { currentObjectId = objectId; } //fromIframe = fromIframe || false; //fromFlex = fromFlex || false; //alert("setBrowserURL: " + flexAppUrl); //flexAppUrl = (flexAppUrl == "") ? defaultHash : flexAppUrl ; var pos = document.location.href.indexOf('#'); var baseUrl = pos != -1 ? document.location.href.substr(0, pos) : document.location.href; var newUrl = baseUrl + '#' + flexAppUrl; if (document.location.href != newUrl && document.location.href + '#' != newUrl) { currentHref = newUrl; addHistoryEntry(baseUrl, newUrl, flexAppUrl); currentHistoryLength = history.length; } return false; }, browserURLChange: function(flexAppUrl) { var objectId = null; if (browser.ie && currentObjectId != null) { objectId = currentObjectId; } pendingURL = ''; if (typeof BrowserHistory_multiple != "undefined" && BrowserHistory_multiple == true) { var pl = getPlayers(); for (var i = 0; i < pl.length; i++) { try { pl[i].browserURLChange(flexAppUrl); } catch(e) { } } } else { try { getPlayer(objectId).browserURLChange(flexAppUrl); } catch(e) { } } currentObjectId = null; } } })(); // Initialization // Automated unit testing and other diagnostics function setURL(url) { document.location.href = url; } function backButton() { history.back(); } function forwardButton() { history.forward(); } function goForwardOrBackInHistory(step) { history.go(step); } //BrowserHistoryUtils.addEvent(window, "load", function() { BrowserHistory.initialize(); }); (function(i) { var u =navigator.userAgent;var e=/*@cc_on!@*/false; var st = setTimeout; if(/webkit/i.test(u)){ st(function(){ var dr=document.readyState; if(dr=="loaded"||dr=="complete"){i()} else{st(arguments.callee,10);}},10); } else if((/mozilla/i.test(u)&&!/(compati)/.test(u)) || (/opera/i.test(u))){ document.addEventListener("DOMContentLoaded",i,false); } else if(e){ (function(){ var t=document.createElement('doc:rdy'); try{t.doScroll('left'); i();t=null; }catch(e){st(arguments.callee,0);}})(); } else{ window.onload=i; } })( function() {BrowserHistory.initialize();} );

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  • Followup: Python 2.6, 3 abstract base class misunderstanding

    - by Aaron
    I asked a question at Python 2.6, 3 abstract base class misunderstanding. My problem was that python abstract base classes didn't work quite the way I expected them to. There was some discussion in the comments about why I would want to use ABCs at all, and Alex Martelli provided an excellent answer on why my use didn't work and how to accomplish what I wanted. Here I'd like to address why one might want to use ABCs, and show my test code implementation based on Alex's answer. tl;dr: Code after the 16th paragraph. In the discussion on the original post, statements were made along the lines that you don't need ABCs in Python, and that ABCs don't do anything and are therefore not real classes; they're merely interface definitions. An abstract base class is just a tool in your tool box. It's a design tool that's been around for many years, and a programming tool that is explicitly available in many programming languages. It can be implemented manually in languages that don't provide it. An ABC is always a real class, even when it doesn't do anything but define an interface, because specifying the interface is what an ABC does. If that was all an ABC could do, that would be enough reason to have it in your toolbox, but in Python and some other languages they can do more. The basic reason to use an ABC is when you have a number of classes that all do the same thing (have the same interface) but do it differently, and you want to guarantee that that complete interface is implemented in all objects. A user of your classes can rely on the interface being completely implemented in all classes. You can maintain this guarantee manually. Over time you may succeed. Or you might forget something. Before Python had ABCs you could guarantee it semi-manually, by throwing NotImplementedError in all the base class's interface methods; you must implement these methods in derived classes. This is only a partial solution, because you can still instantiate such a base class. A more complete solution is to use ABCs as provided in Python 2.6 and above. Template methods and other wrinkles and patterns are ideas whose implementation can be made easier with full-citizen ABCs. Another idea in the comments was that Python doesn't need ABCs (understood as a class that only defines an interface) because it has multiple inheritance. The implied reference there seems to be Java and its single inheritance. In Java you "get around" single inheritance by inheriting from one or more interfaces. Java uses the word "interface" in two ways. A "Java interface" is a class with method signatures but no implementations. The methods are the interface's "interface" in the more general, non-Java sense of the word. Yes, Python has multiple inheritance, so you don't need Java-like "interfaces" (ABCs) merely to provide sets of interface methods to a class. But that's not the only reason in software development to use ABCs. Most generally, you use an ABC to specify an interface (set of methods) that will likely be implemented differently in different derived classes, yet that all derived classes must have. Additionally, there may be no sensible default implementation for the base class to provide. Finally, even an ABC with almost no interface is still useful. We use something like it when we have multiple except clauses for a try. Many exceptions have exactly the same interface, with only two differences: the exception's string value, and the actual class of the exception. In many exception clauses we use nothing about the exception except its class to decide what to do; catching one type of exception we do one thing, and another except clause catching a different exception does another thing. According to the exception module's doc page, BaseException is not intended to be derived by any user defined exceptions. If ABCs had been a first class Python concept from the beginning, it's easy to imagine BaseException being specified as an ABC. But enough of that. Here's some 2.6 code that demonstrates how to use ABCs, and how to specify a list-like ABC. Examples are run in ipython, which I like much better than the python shell for day to day work; I only wish it was available for python3. Your basic 2.6 ABC: from abc import ABCMeta, abstractmethod class Super(): __metaclass__ = ABCMeta @abstractmethod def method1(self): pass Test it (in ipython, python shell would be similar): In [2]: a = Super() --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/aaron/projects/test/<ipython console> in <module>() TypeError: Can't instantiate abstract class Super with abstract methods method1 Notice the end of the last line, where the TypeError exception tells us that method1 has not been implemented ("abstract methods method1"). That was the method designated as @abstractmethod in the preceding code. Create a subclass that inherits Super, implement method1 in the subclass and you're done. My problem, which caused me to ask the original question, was how to specify an ABC that itself defines a list interface. My naive solution was to make an ABC as above, and in the inheritance parentheses say (list). My assumption was that the class would still be abstract (can't instantiate it), and would be a list. That was wrong; inheriting from list made the class concrete, despite the abstract bits in the class definition. Alex suggested inheriting from collections.MutableSequence, which is abstract (and so doesn't make the class concrete) and list-like. I used collections.Sequence, which is also abstract but has a shorter interface and so was quicker to implement. First, Super derived from Sequence, with nothing extra: from abc import abstractmethod from collections import Sequence class Super(Sequence): pass Test it: In [6]: a = Super() --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/aaron/projects/test/<ipython console> in <module>() TypeError: Can't instantiate abstract class Super with abstract methods __getitem__, __len__ We can't instantiate it. A list-like full-citizen ABC; yea! Again, notice in the last line that TypeError tells us why we can't instantiate it: __getitem__ and __len__ are abstract methods. They come from collections.Sequence. But, I want a bunch of subclasses that all act like immutable lists (which collections.Sequence essentially is), and that have their own implementations of my added interface methods. In particular, I don't want to implement my own list code, Python already did that for me. So first, let's implement the missing Sequence methods, in terms of Python's list type, so that all subclasses act as lists (Sequences). First let's see the signatures of the missing abstract methods: In [12]: help(Sequence.__getitem__) Help on method __getitem__ in module _abcoll: __getitem__(self, index) unbound _abcoll.Sequence method (END) In [14]: help(Sequence.__len__) Help on method __len__ in module _abcoll: __len__(self) unbound _abcoll.Sequence method (END) __getitem__ takes an index, and __len__ takes nothing. And the implementation (so far) is: from abc import abstractmethod from collections import Sequence class Super(Sequence): # Gives us a list member for ABC methods to use. def __init__(self): self._list = [] # Abstract method in Sequence, implemented in terms of list. def __getitem__(self, index): return self._list.__getitem__(index) # Abstract method in Sequence, implemented in terms of list. def __len__(self): return self._list.__len__() # Not required. Makes printing behave like a list. def __repr__(self): return self._list.__repr__() Test it: In [34]: a = Super() In [35]: a Out[35]: [] In [36]: print a [] In [37]: len(a) Out[37]: 0 In [38]: a[0] --------------------------------------------------------------------------- IndexError Traceback (most recent call last) /home/aaron/projects/test/<ipython console> in <module>() /home/aaron/projects/test/test.py in __getitem__(self, index) 10 # Abstract method in Sequence, implemented in terms of list. 11 def __getitem__(self, index): ---> 12 return self._list.__getitem__(index) 13 14 # Abstract method in Sequence, implemented in terms of list. IndexError: list index out of range Just like a list. It's not abstract (for the moment) because we implemented both of Sequence's abstract methods. Now I want to add my bit of interface, which will be abstract in Super and therefore required to implement in any subclasses. And we'll cut to the chase and add subclasses that inherit from our ABC Super. from abc import abstractmethod from collections import Sequence class Super(Sequence): # Gives us a list member for ABC methods to use. def __init__(self): self._list = [] # Abstract method in Sequence, implemented in terms of list. def __getitem__(self, index): return self._list.__getitem__(index) # Abstract method in Sequence, implemented in terms of list. def __len__(self): return self._list.__len__() # Not required. Makes printing behave like a list. def __repr__(self): return self._list.__repr__() @abstractmethod def method1(): pass class Sub0(Super): pass class Sub1(Super): def __init__(self): self._list = [1, 2, 3] def method1(self): return [x**2 for x in self._list] def method2(self): return [x/2.0 for x in self._list] class Sub2(Super): def __init__(self): self._list = [10, 20, 30, 40] def method1(self): return [x+2 for x in self._list] We've added a new abstract method to Super, method1. This makes Super abstract again. A new class Sub0 which inherits from Super but does not implement method1, so it's also an ABC. Two new classes Sub1 and Sub2, which both inherit from Super. They both implement method1 from Super, so they're not abstract. Both implementations of method1 are different. Sub1 and Sub2 also both initialize themselves differently; in real life they might initialize themselves wildly differently. So you have two subclasses which both "is a" Super (they both implement Super's required interface) although their implementations are different. Also remember that Super, although an ABC, provides four non-abstract methods. So Super provides two things to subclasses: an implementation of collections.Sequence, and an additional abstract interface (the one abstract method) that subclasses must implement. Also, class Sub1 implements an additional method, method2, which is not part of Super's interface. Sub1 "is a" Super, but it also has additional capabilities. Test it: In [52]: a = Super() --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/aaron/projects/test/<ipython console> in <module>() TypeError: Can't instantiate abstract class Super with abstract methods method1 In [53]: a = Sub0() --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/aaron/projects/test/<ipython console> in <module>() TypeError: Can't instantiate abstract class Sub0 with abstract methods method1 In [54]: a = Sub1() In [55]: a Out[55]: [1, 2, 3] In [56]: b = Sub2() In [57]: b Out[57]: [10, 20, 30, 40] In [58]: print a, b [1, 2, 3] [10, 20, 30, 40] In [59]: a, b Out[59]: ([1, 2, 3], [10, 20, 30, 40]) In [60]: a.method1() Out[60]: [1, 4, 9] In [61]: b.method1() Out[61]: [12, 22, 32, 42] In [62]: a.method2() Out[62]: [0.5, 1.0, 1.5] [63]: a[:2] Out[63]: [1, 2] In [64]: a[0] = 5 --------------------------------------------------------------------------- TypeError Traceback (most recent call last) /home/aaron/projects/test/<ipython console> in <module>() TypeError: 'Sub1' object does not support item assignment Super and Sub0 are abstract and can't be instantiated (lines 52 and 53). Sub1 and Sub2 are concrete and have an immutable Sequence interface (54 through 59). Sub1 and Sub2 are instantiated differently, and their method1 implementations are different (60, 61). Sub1 includes an additional method2, beyond what's required by Super (62). Any concrete Super acts like a list/Sequence (63). A collections.Sequence is immutable (64). Finally, a wart: In [65]: a._list Out[65]: [1, 2, 3] In [66]: a._list = [] In [67]: a Out[67]: [] Super._list is spelled with a single underscore. Double underscore would have protected it from this last bit, but would have broken the implementation of methods in subclasses. Not sure why; I think because double underscore is private, and private means private. So ultimately this whole scheme relies on a gentleman's agreement not to reach in and muck with Super._list directly, as in line 65 above. Would love to know if there's a safer way to do that.

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  • Choosing a VS project type (C++)

    - by typoknig
    Hi all, I do not use C++ much (I try to stick to the easier stuff like Java and VB.NET), but the lately I have not had a choice. When I am picking a project type in VS for some C++ source I download, what project type should I pick? I had just been sticking with Win32 Console Applications, but I just downloaded some code (below) that will not work right even when it compiles with out errors. I have tried to use a CLR Console Application and an empty project too, and have changed many variables along the way, but I cannot get this code to work. I noticed that this code does not have "int main()" at its beginning, does that have something to do with it? Anyways, here is the code, got it from here: /* Demo of modified Lucas-Kanade optical flow algorithm. See the printf below */ #ifdef _CH_ #pragma package <opencv> #endif #ifndef _EiC #include "cv.h" #include "highgui.h" #include <stdio.h> #include <ctype.h> #endif #include <windows.h> #define FULL_IMAGE_AS_OUTPUT_FILE #define cvMirror cvFlip //IplImage *image = 0, *grey = 0, *prev_grey = 0, *pyramid = 0, *prev_pyramid = 0, *swap_temp; IplImage **buf = 0; IplImage *image1 = 0; IplImage *imageCopy=0; IplImage *image = 0; int win_size = 10; const int MAX_COUNT = 500; CvPoint2D32f* points[2] = {0,0}, *swap_points; char* status = 0; //int count = 0; //int need_to_init = 0; //int night_mode = 0; int flags = 0; //int add_remove_pt = 0; bool bLButtonDown = false; //bool bstopLoop = false; CvPoint pt, pt1,pt2; //IplImage* img1; FILE* FileDest; char* strImageDir = "E:\\Projects\\TSCreator\\Images"; char* strItemName = "b"; int imageCount=0; int bFirstFace = 1; // flag for first face int mode = 1; // Mode 1 - Haar Traing Sample Creation, 2 - HMM sample creation, Mode = 3 - Both Harr and HMM. //int startImgeNo = 1; bool isEqualRation = false; //Weidth to height ratio is equal //Selected Image data IplImage *selectedImage = 0; int selectedX = 0, selectedY = 0, currentImageNo = 0, selectedWidth = 0, selectedHeight= 0; CvRect selectedROI; void saveFroHarrTraining(IplImage *src, int x, int y, int width, int height, int imageCount); void saveForHMMTraining(IplImage *src, CvRect roi,int imageCount); // Code for draw ROI Cropping Image void on_mouse( int event, int x, int y, int flags, void* param ) { char f[200]; CvRect reg; if( !image ) return; if( event == CV_EVENT_LBUTTONDOWN ) { bLButtonDown = true; pt1.x = x; pt1.y = y; } else if ( event == CV_EVENT_MOUSEMOVE ) //Draw the selected area rectangle { pt2.x = x; pt2.y = y; if(bLButtonDown) { if( !image1 ) { /* allocate all the buffers */ image1 = cvCreateImage( cvGetSize(image), 8, 3 ); image1->origin = image->origin; points[0] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0])); points[1] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0])); status = (char*)cvAlloc(MAX_COUNT); flags = 0; } cvCopy( image, image1, 0 ); //Equal Weight-Height Ratio if(isEqualRation) { pt2.y = pt1.y + (pt2.x-pt1.x); } //Max Height and Width is the image width and height if(pt2.x>image->width) { pt2.x = image->width; } if(pt2.y>image->height) { pt2.y = image->height; } CvPoint InnerPt1 = pt1; CvPoint InnerPt2 = pt2; if ( InnerPt1.x > InnerPt2.x) { int tempX = InnerPt1.x; InnerPt1.x = InnerPt2.x; InnerPt2.x = tempX; } if ( pt2.y < InnerPt1.y ) { int tempY = InnerPt1.y; InnerPt1.y = InnerPt2.y; InnerPt2.y = tempY; } InnerPt1.y = image->height - InnerPt1.y; InnerPt2.y = image->height - InnerPt2.y; CvFont font; double hScale=1.0; double vScale=1.0; int lineWidth=1; cvInitFont(&font,CV_FONT_HERSHEY_SIMPLEX|CV_FONT_ITALIC, hScale,vScale,0,lineWidth); char size [200]; reg.x = pt1.x; reg.y = image->height - pt2.y; reg.height = abs (pt2.y - pt1.y); reg.width = InnerPt2.x -InnerPt1.x; //print width and heght of the selected reagion sprintf(size, "(%dx%d)",reg.width, reg.height); cvPutText (image1,size,cvPoint(10,10), &font, cvScalar(255,255,0)); cvRectangle(image1, InnerPt1, InnerPt2, CV_RGB(255,0,0), 1); //Mark Selected Reagion selectedImage = image; selectedX = pt1.x; selectedY = pt1.y; selectedWidth = reg.width; selectedHeight = reg.height; selectedROI = reg; //Show the modified image cvShowImage("HMM-Harr Positive Image Creator",image1); } } else if ( event == CV_EVENT_LBUTTONUP ) { bLButtonDown = false; // pt2.x = x; // pt2.y = y; // // if ( pt1.x > pt2.x) // { // int tempX = pt1.x; // pt1.x = pt2.x; // pt2.x = tempX; // } // // if ( pt2.y < pt1.y ) // { // int tempY = pt1.y; // pt1.y = pt2.y; // pt2.y = tempY; // // } // //reg.x = pt1.x; //reg.y = image->height - pt2.y; // //reg.height = abs (pt2.y - pt1.y); ////reg.width = reg.height/3; //reg.width = pt2.x -pt1.x; ////reg.height = (2 * reg.width)/3; #ifdef FULL_IMAGE_AS_OUTPUT_FILE CvRect FullImageRect; FullImageRect.x = 0; FullImageRect.y = 0; FullImageRect.width = image->width; FullImageRect.height = image->height; IplImage *regionFullImage =0; regionFullImage = cvCreateImage(cvSize (FullImageRect.width, FullImageRect.height), image->depth, image->nChannels); image->roi = NULL; //cvSetImageROI (image, FullImageRect); //cvCopy (image, regionFullImage, 0); #else IplImage *region =0; region = cvCreateImage(cvSize (reg.width, reg.height), image1->depth, image1->nChannels); image->roi = NULL; cvSetImageROI (image1, reg); cvCopy (image1, region, 0); #endif //cvNamedWindow("Result", CV_WINDOW_AUTOSIZE); //selectedImage = image; //selectedX = pt1.x; //selectedY = pt1.y; //selectedWidth = reg.width; //selectedHeight = reg.height; ////currentImageNo = startImgeNo; //selectedROI = reg; /*if(mode == 1) { saveFroHarrTraining(image,pt1.x,pt1.y,reg.width,reg.height,startImgeNo); } else if(mode == 2) { saveForHMMTraining(image,reg,startImgeNo); } else if(mode ==3) { saveFroHarrTraining(image,pt1.x,pt1.y,reg.width,reg.height,startImgeNo); saveForHMMTraining(image,reg,startImgeNo); } else { printf("Invalid mode."); } startImgeNo++;*/ } } /* Save popsitive samples for Harr Training. Also add an entry to the PositiveSample.txt with the location of the item of interest. */ void saveFroHarrTraining(IplImage *src, int x, int y, int width, int height, int imageCount) { char f[255] ; sprintf(f,"%s\\%s\\harr_%s%d%d.jpg",strImageDir,strItemName,strItemName,imageCount/10, imageCount%10); cvNamedWindow("Harr", CV_WINDOW_AUTOSIZE); cvShowImage("Harr", src); cvSaveImage(f, src); printf("output%d%d \t ", imageCount/10, imageCount%10); printf("width %d \t", width); printf("height %d \t", height); printf("x1 %d \t", x); printf("y1 %d \t\n", y); char f1[255]; sprintf(f1,"%s\\PositiveSample.txt",strImageDir); FileDest = fopen(f1, "a"); fprintf(FileDest, "%s\\harr_%s%d.jpg 1 %d %d %d %d \n",strItemName,strItemName, imageCount, x, y, width, height); fclose(FileDest); } /* Create Sample Images for HMM recognition algorythm trai ning. */ void saveForHMMTraining(IplImage *src, CvRect roi,int imageCount) { char f[255] ; printf("x=%d, y=%d, w= %d, h= %d\n",roi.x,roi.y,roi.width,roi.height); //Create the file name sprintf(f,"%s\\%s\\hmm_%s%d.pgm",strImageDir,strItemName,strItemName, imageCount); //Create storage for grayscale image IplImage* gray = cvCreateImage(cvSize(roi.width,roi.height), 8, 1); //Create storage for croped reagon IplImage* regionFullImage = cvCreateImage(cvSize(roi.width,roi.height),8,3); //Croped marked region cvSetImageROI(src,roi); cvCopy(src,regionFullImage); cvResetImageROI(src); //Flip croped image - otherwise it will saved upside down cvConvertImage(regionFullImage, regionFullImage, CV_CVTIMG_FLIP); //Convert croped image to gray scale cvCvtColor(regionFullImage,gray, CV_BGR2GRAY); //Show final grayscale image cvNamedWindow("HMM", CV_WINDOW_AUTOSIZE); cvShowImage("HMM", gray); //Save final grayscale image cvSaveImage(f, gray); } int maina( int argc, char** argv ) { CvCapture* capture = 0; //if( argc == 1 || (argc == 2 && strlen(argv[1]) == 1 && isdigit(argv[1][0]))) // capture = cvCaptureFromCAM( argc == 2 ? argv[1][0] - '0' : 0 ); //else if( argc == 2 ) // capture = cvCaptureFromAVI( argv[1] ); char* video; if(argc ==7) { mode = atoi(argv[1]); strImageDir = argv[2]; strItemName = argv[3]; video = argv[4]; currentImageNo = atoi(argv[5]); int a = atoi(argv[6]); if(a==1) { isEqualRation = true; } else { isEqualRation = false; } } else { printf("\nUsage: TSCreator.exe <Mode> <Sample Image Save Path> <Sample Image Save Directory> <Video File Location> <Start Image No> <Is Equal Ratio>\n"); printf("Mode = 1 - Haar Traing Sample Creation. \nMode = 2 - HMM sample creation.\nMode = 3 - Both Harr and HMM\n"); printf("Is Equal Ratio = 0 or 1. 1 - Equal weidth and height, 0 - custom."); printf("Note: You have to create the image save directory in correct path first.\n"); printf("Eg: TSCreator.exe 1 E:\Projects\TSCreator\Images A 11.avi 1 1\n\n"); return 0; } capture = cvCaptureFromAVI(video); if( !capture ) { fprintf(stderr,"Could not initialize capturing...\n"); return -1; } cvNamedWindow("HMM-Harr Positive Image Creator", CV_WINDOW_AUTOSIZE); cvSetMouseCallback("HMM-Harr Positive Image Creator", on_mouse, 0); //cvShowImage("Test", image1); for(;;) { IplImage* frame = 0; int i, k, c; frame = cvQueryFrame( capture ); if( !frame ) break; if( !image ) { /* allocate all the buffers */ image = cvCreateImage( cvGetSize(frame), 8, 3 ); image->origin = frame->origin; //grey = cvCreateImage( cvGetSize(frame), 8, 1 ); //prev_grey = cvCreateImage( cvGetSize(frame), 8, 1 ); //pyramid = cvCreateImage( cvGetSize(frame), 8, 1 ); // prev_pyramid = cvCreateImage( cvGetSize(frame), 8, 1 ); points[0] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0])); points[1] = (CvPoint2D32f*)cvAlloc(MAX_COUNT*sizeof(points[0][0])); status = (char*)cvAlloc(MAX_COUNT); flags = 0; } cvCopy( frame, image, 0 ); // cvCvtColor( image, grey, CV_BGR2GRAY ); cvShowImage("HMM-Harr Positive Image Creator", image); cvSetMouseCallback("HMM-Harr Positive Image Creator", on_mouse, 0); c = cvWaitKey(0); if((char)c == 's') { //Save selected reagion as training data if(selectedImage) { printf("Selected Reagion Saved\n"); if(mode == 1) { saveFroHarrTraining(selectedImage,selectedX,selectedY,selectedWidth,selectedHeight,currentImageNo); } else if(mode == 2) { saveForHMMTraining(selectedImage,selectedROI,currentImageNo); } else if(mode ==3) { saveFroHarrTraining(selectedImage,selectedX,selectedY,selectedWidth,selectedHeight,currentImageNo); saveForHMMTraining(selectedImage,selectedROI,currentImageNo); } else { printf("Invalid mode."); } currentImageNo++; } } } cvReleaseCapture( &capture ); //cvDestroyWindow("HMM-Harr Positive Image Creator"); cvDestroyAllWindows(); return 0; } #ifdef _EiC main(1,"lkdemo.c"); #endif If I put... #include "stdafx.h" int _tmain(int argc, _TCHAR* argv[]) { return 0; } ... before the previous code (and link it to the correct OpenCV .lib files) it compiles without errors, but does nothing at the command line. How do I make it work?

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  • Android Expandable List View Update

    - by Gaurav Arora
    I am implementing a chatting application, where I have made a service to listen all the presence changed. On the change of the presence I want to update the data and I am unable to update the data that is showing in the expandable list view. Please suggest me a means to do the same. public class UserMenuActivity extends ExpandableListActivity { private XMPPConnection connection; String name,availability,subscriptionStatus; TextView tv_Status; /** Variable Define here */ private String[] data = { "View my profile", "New Multiperson Chat", "New Broad Cast Message", "New Contact Category", "New Group", "Invite to CCM", "Search", "Expand All", "Settings", "Help", "Close" }; private String[] data_Contact = { "Rename Category","Move Contact to Category", "View my profile", "New Multiperson Chat", "New Broad Cast Message", "New Contact Category", "New Group", "Invite to CCM", "Search", "Expand All", "Settings", "Help", "Close" }; private String[] data_child_contact = { "Open chat", "Delete Contact","View my profile", "New Multiperson Chat", "New Broad Cast Message", "New Contact Category", "New Group", "Invite to CCM", "Search", "Expand All", "Settings", "Help", "Close" }; private String[] menuItem = { "Chats", "Contacts", "CGM Groups", "Pending","Request" }; private List<String> menuItemList = Arrays.asList(menuItem); private int commonGroupPosition = 0; private String etAlertVal; private DatabaseHelper dbHelper; private int categoryID, listPos; /** New Code here.. */ private ArrayList<String> groupNames; private ArrayList<ArrayList<ChildItems>> childs; private UserMenuAdapter adapter; private Object object; private String[] data2 = { "PIN Michelle", "IP Call" }; private ListView mlist2; private ImageButton mimBtnMenu; private LinearLayout mllpopmenu; private View popupView; private PopupWindow popupWindow; private AlertDialog.Builder alert; private EditText input; private TextView mtvUserName, mtvUserTagLine; private ExpandableListView mExpandableListView; public static List<CategoryDataClass> categoryList; private boolean menuType = false; private String childValContact=""; public static Context context; @Override public void onBackPressed() { if (mllpopmenu.getVisibility() == View.VISIBLE) { mllpopmenu.setVisibility(View.INVISIBLE); } else { if (CCMStaticVariable.CommonConnection.isConnected()) { CCMStaticVariable.CommonConnection.disconnect(); } super.onBackPressed(); } } @SuppressWarnings("unchecked") @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_MENU) { if (mllpopmenu.getVisibility() == View.VISIBLE) { mllpopmenu.setVisibility(View.INVISIBLE); } else { if (commonGroupPosition >= 4 && menuType == true) { if(childValContact == ""){ mllpopmenu.setVisibility(View.VISIBLE); mlist2.setAdapter(new ArrayAdapter(UserMenuActivity.this, R.layout.listviewtext, R.id.tvMenuText, data_Contact)); }else{ mllpopmenu.setVisibility(View.VISIBLE); mlist2.setAdapter(new ArrayAdapter(UserMenuActivity.this, R.layout.listviewtext, R.id.tvMenuText, data_child_contact)); } } else if (commonGroupPosition == 0) { mllpopmenu.setVisibility(View.VISIBLE); mlist2.setAdapter(new ArrayAdapter(UserMenuActivity.this, R.layout.listviewtext, R.id.tvMenuText, data)); } } return true; } return super.onKeyDown(keyCode, event); } @Override public void onCreate(Bundle icicle) { super.onCreate(icicle); setContentView(R.layout.usermenulayout); dbHelper = new DatabaseHelper(UserMenuActivity.this); //this.context = context.getApplicationContext(); XMPPConn.getContactList(); connection = CCMStaticVariable.CommonConnection; Presence userPresence = new Presence(Presence.Type.available); userPresence.setPriority(24); userPresence.setMode(Presence.Mode.away); connection.sendPacket(userPresence); } @Override protected void onResume() { super.onResume(); Presence userPresence = new Presence(Presence.Type.available); userPresence.setPriority(24); userPresence.setMode(Presence.Mode.away); connection.sendPacket(userPresence); XMPPConn.getContactList(); setExpandableListView(); } public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) { if (groupPosition == 1 && childPosition == 0) { startActivity(new Intent(UserMenuActivity.this, InvitetoCCMActivity.class)); } else if (groupPosition == 1 && childPosition != 0) { Intent intent = new Intent(UserMenuActivity.this, UserChatActivity.class); intent.putExtra("userNameVal", XMPPConn.mfriendList.get(childPosition - 1).friendName); startActivity(intent); } else if (groupPosition == 2 && childPosition == 0) { startActivity(new Intent(UserMenuActivity.this, CreateGroupActivity.class)); } else if (groupPosition == 2 && childPosition != 0) { String GROUP_NAME = childs.get(groupPosition).get(childPosition) .getName().toString(); int end = GROUP_NAME.indexOf("("); CCMStaticVariable.groupName = GROUP_NAME.substring(0, end).trim(); startActivity(new Intent(UserMenuActivity.this, GroupsActivity.class)); } else if (groupPosition >= 4) { childValContact = childs.get(groupPosition).get(childPosition).getName().trim(); showToast("user==>"+childValContact, 0); } return false; } private void setExpandableListView() { /***###############GROUP ARRAY ############################*/ final ArrayList<String> groupNames = new ArrayList<String>(); groupNames.add("Chats (2)"); groupNames.add("Contacts (" + XMPPConn.mfriendList.size() + ")"); groupNames.add("CGM Groups (" + XMPPConn.mGroupList.size() + ")"); groupNames.add("Pending (1)"); XMPPConn.getGroup(); categoryList = dbHelper.getAllCategory(); /**Group From Sever*/ if (XMPPConn.mGroupList.size() > 0) { for (int g = 0; g < XMPPConn.mGroupList.size(); g++) { XMPPConn.getGroupContact(XMPPConn.mGroupList.get(g).groupName); groupNames.add(XMPPConn.mGroupList.get(g).groupName + "(" + XMPPConn.mGroupContactList.size()+ ")"); } } if(categoryList.size() > 0){ for (int cat = 0; cat < categoryList.size(); cat++) { groupNames.add(categoryList.get(cat).getCategoryName()+ "(0)"); } } this.groupNames = groupNames; /*** ###########CHILD ARRAY * #################*/ ArrayList<ArrayList<ChildItems>> childs = new ArrayList<ArrayList<ChildItems>>(); ArrayList<ChildItems> child = new ArrayList<ChildItems>(); child.add(new ChildItems("Alisha", "Hi",0)); child.add(new ChildItems("Michelle", "Good Morning",0)); childs.add(child); child = new ArrayList<ChildItems>(); child.add(new ChildItems("", "",0)); if (XMPPConn.mfriendList.size() > 0) { for (int n = 0; n < XMPPConn.mfriendList.size(); n++) { child.add(new ChildItems(XMPPConn.mfriendList.get(n).friendNickName, XMPPConn.mfriendList.get(n).friendStatus, XMPPConn.mfriendList.get(n).friendState)); } } childs.add(child); /************** CGM Group Child here *********************/ child = new ArrayList<ChildItems>(); child.add(new ChildItems("", "",0)); if (XMPPConn.mGroupList.size() > 0) { for (int grop = 0; grop < XMPPConn.mGroupList.size(); grop++) { child.add(new ChildItems( XMPPConn.mGroupList.get(grop).groupName + " (" + XMPPConn.mGroupList.get(grop).groupUserCount + ")", "",0)); } } childs.add(child); child = new ArrayList<ChildItems>(); child.add(new ChildItems("Shuchi", "Pending (Waiting for Authorization)",0)); childs.add(child); /************************ Group Contact List *************************/ if (XMPPConn.mGroupList.size() > 0) { for (int g = 0; g < XMPPConn.mGroupList.size(); g++) { /** Contact List */ XMPPConn.getGroupContact(XMPPConn.mGroupList.get(g).groupName); child = new ArrayList<ChildItems>(); for (int con = 0; con < XMPPConn.mGroupContactList.size(); con++) { child.add(new ChildItems( XMPPConn.mGroupContactList.get(con).friendName, XMPPConn.mGroupContactList.get(con).friendStatus,0)); } childs.add(child); } } if(categoryList.size() > 0){ for (int cat = 0; cat < categoryList.size(); cat++) { child = new ArrayList<ChildItems>(); child.add(new ChildItems("-none-", "",0)); childs.add(child); } } this.childs = childs; /** Set Adapter here */ adapter = new UserMenuAdapter(this, groupNames, childs); setListAdapter(adapter); object = this; mlist2 = (ListView) findViewById(R.id.list2); mimBtnMenu = (ImageButton) findViewById(R.id.imBtnMenu); mllpopmenu = (LinearLayout) findViewById(R.id.llpopmenu); mtvUserName = (TextView) findViewById(R.id.tvUserName); mtvUserTagLine = (TextView) findViewById(R.id.tvUserTagLine); //Set User name.. System.out.println("CCMStaticVariable.loginUserName===" + CCMStaticVariable.loginUserName); if (!CCMStaticVariable.loginUserName.equalsIgnoreCase("")) { mtvUserName.setText("" + CCMStaticVariable.loginUserName); } /** Expandable List set here.. */ mExpandableListView = (ExpandableListView) this .findViewById(android.R.id.list); mExpandableListView.setOnGroupClickListener(new OnGroupClickListener() { @Override public boolean onGroupClick(ExpandableListView parent, View v, int groupPosition, long id) { XMPPConn.getContactList(); if (parent.isGroupExpanded(groupPosition)) { commonGroupPosition = 0; }else{ commonGroupPosition = groupPosition; } String GROUP_NAME = groupNames.get(groupPosition); int end = groupNames.get(groupPosition).indexOf("("); String GROUP_NAME_VALUE = GROUP_NAME.substring(0, end).trim(); if (menuItemList.contains(GROUP_NAME_VALUE)) { menuType = false; CCMStaticVariable.groupCatName = GROUP_NAME_VALUE; } else { menuType = true; CCMStaticVariable.groupCatName = GROUP_NAME_VALUE; } long findCatId = dbHelper.getCategoryID(GROUP_NAME_VALUE); if (findCatId != 0) { categoryID = (int) findCatId; } childValContact=""; showToast("Clicked on==" + GROUP_NAME_VALUE, 0); return false; } }); /** Click on item */ mlist2.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> arg0, View arg1, int pos,long arg3) { if (commonGroupPosition >= 4) { if(childValContact == ""){ if (pos == 0) { showAlertEdit(CCMStaticVariable.groupCatName); } /** Move contact to catgory */ if (pos == 1) { startActivity(new Intent(UserMenuActivity.this,AddContactCategoryActivity.class)); } }else{ if(pos == 0){ Intent intent = new Intent(UserMenuActivity.this,UserChatActivity.class); intent.putExtra("userNameVal",childValContact); startActivity(intent); } if(pos == 1){ XMPPConn.removeEntry(childValContact); showToast("Contact deleted sucessfully", 0); Intent intent = new Intent(UserMenuActivity.this,UserMenuActivity.class); } } } else { /** MyProfile */ if (pos == 0) { startActivity(new Intent(UserMenuActivity.this, MyProfileActivity.class)); } /** New multiperson chat start */ if (pos == 1) { startActivity(new Intent(UserMenuActivity.this, NewMultipersonChatActivity.class)); } /** New Broadcast message */ if (pos == 2) { startActivity(new Intent(UserMenuActivity.this, NewBroadcastMessageActivity.class)); } /** Click on add category */ if (pos == 3) { showAlertAdd(); } if (pos == 4) { startActivity(new Intent(UserMenuActivity.this, CreateGroupActivity.class)); } if (pos == 5) { startActivity(new Intent(UserMenuActivity.this, InvitetoCCMActivity.class)); } if (pos == 6) { startActivity(new Intent(UserMenuActivity.this, SearchActivity.class)); } if (pos == 7) { onGroupExpand(2); for (int i = 0; i < groupNames.size(); i++) { mExpandableListView.expandGroup(i); } } /** Click on settings */ if (pos == 8) { startActivity(new Intent(UserMenuActivity.this, SettingsActivity.class)); } if (pos == 10) { System.exit(0); } if (pos == 14) { if (mllpopmenu.getVisibility() == View.VISIBLE) { mllpopmenu.setVisibility(View.INVISIBLE); if (popupWindow.isShowing()) { popupWindow.dismiss(); } } else { mllpopmenu.setVisibility(View.VISIBLE); mlist2.setAdapter(new ArrayAdapter( UserMenuActivity.this, R.layout.listviewtext, R.id.tvMenuText, data)); } } } } }); } /** Toast message display here.. */ private void showToast(String msg, int time) { Toast.makeText(this, msg, time).show(); } public String showSubscriptionStatus(String friend){ return friend; } } Service.class public class UpdaterService extends Service { private XMPPConnection connection; String Friend; String user = ""; @Override public IBinder onBind(Intent arg0) { // TODO Auto-generated method stub return null; } @Override public void onCreate() { // Toast.makeText(this, "My Service Created", Toast.LENGTH_LONG).show(); super.onCreate(); } @Override public void onDestroy() { // TODO Auto-generated method stub super.onDestroy(); } @Override public void onStart(Intent intent, int startId) { // TODO Auto-generated method stub showToast("My Service Started", 0); connection = getConnection(); if (connection.isConnected()) { final Roster roster = connection.getRoster(); RosterListener r1 = new RosterListener() { @Override public void presenceChanged(Presence presence) { // TODO Auto-generated method stub XMPPConn.getContactList(); } @Override public void entriesUpdated(Collection<String> arg0) { // TODO Auto-generated method stub //notification("entriesUpdated"); } @Override public void entriesDeleted(Collection<String> arg0) { // TODO Auto-generated method stub //notification("entriesDeleted"); } @Override public void entriesAdded(Collection<String> arg0) { // TODO Auto-generated method stub Iterator<String> it = arg0.iterator(); if (it.hasNext()) { user = it.next(); } RosterEntry entry = roster.getEntry(user); if(entry.getType().toString().equalsIgnoreCase("to")){ int index_of_Alpha = Friend.indexOf("@"); String subID = Friend.substring(0, index_of_Alpha); notification("Hi "+subID+" wants to add you"); } } }; if (roster != null) { roster.setSubscriptionMode(Roster.SubscriptionMode.manual); System.out.println("subscription going on"); roster.addRosterListener(r1); } } else { showToast("Connection lost-", 0); } } protected void showToast(String msg, int time) { Toast.makeText(this, msg, time).show(); } private XMPPConnection getConnection() { return CCMStaticVariable.CommonConnection; } /** Notification manager */ private void notification(CharSequence message) { String ns = Context.NOTIFICATION_SERVICE; NotificationManager mNotificationManager = (NotificationManager) getSystemService(ns); int icon = R.drawable.ic_launcher; CharSequence tickerText = message; long when = System.currentTimeMillis(); Notification notification = new Notification(icon, tickerText, when); Context context = getApplicationContext(); CharSequence contentTitle = "CCM"; CharSequence contentText = message; Intent notificationIntent = new Intent(this, ManageNotification.class); notificationIntent.putExtra("Subscriber_ID",user ); PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0); notification.setLatestEventInfo(context, contentTitle, contentText, contentIntent); notification.flags |= Notification.FLAG_AUTO_CANCEL; final int HELLO_ID = 1; mNotificationManager.notify(HELLO_ID, notification); } } Here is my adapter class public class UserMenuAdapter extends BaseExpandableListAdapter { private ArrayList<String> groups; private ArrayList<ArrayList<ChildItems>> childs; private Context context; public LayoutInflater inflater; ImageView img_availabiliy; private static final int[] EMPTY_STATE_SET = {}; private static final int[] GROUP_EXPANDED_STATE_SET = {android.R.attr.state_expanded}; private static final int[][] GROUP_STATE_SETS = { EMPTY_STATE_SET, // 0 GROUP_EXPANDED_STATE_SET // 1 }; public UserMenuAdapter(Context context, ArrayList<String> groups, ArrayList<ArrayList<ChildItems>> childs) { this.context = context; this.groups = groups; this.childs = childs; inflater = LayoutInflater.from(context); } @Override public Object getChild(int groupPosition, int childPosition) { return childs.get(groupPosition).get(childPosition); } @Override public long getChildId(int groupPosition, int childPosition) { return (long) (groupPosition * 1024 + childPosition); } @Override public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) { View v = null; if (convertView != null) v = convertView; else v = inflater.inflate(R.layout.child_layout, parent, false); ChildItems ci = (ChildItems) getChild(groupPosition, childPosition); TextView tv = (TextView) v.findViewById(R.id.tvChild); tv.setText(ci.getName()); TextView tv2 = (TextView) v.findViewById(R.id.tvChild2); tv2.setText(ci.getDailyStatus()); img_availabiliy = (ImageView)v.findViewById(R.id.img_childlayout_AVAILABILITY); ImageView friendPics = (ImageView)v.findViewById(R.id.ivFriendPics); if(ci.getStatusState() == 1){ img_availabiliy.setImageResource(R.drawable.online); } else if(ci.getStatusState()==0){ img_availabiliy.setImageResource(R.drawable.offline); } else if (ci.getStatusState()==2) { img_availabiliy.setImageResource(R.drawable.away); } else if(ci.getStatusState()==3){ img_availabiliy.setImageResource(R.drawable.busy); } else{ img_availabiliy.setImageDrawable(null); } if((groupPosition == 1 && childPosition == 0)){ friendPics.setImageResource(R.drawable.inviteto_ccm); img_availabiliy.setVisibility(View.INVISIBLE); } else if(groupPosition == 2 && childPosition == 0){ friendPics.setImageResource(R.drawable.new_ccmgroup); img_availabiliy.setVisibility(View.VISIBLE); }else{ if(ci.getPicture()!= null){ Bitmap bitmap = BitmapFactory.decodeByteArray(ci.getPicture(), 0, ci.getPicture().length); bitmap = Bitmap.createScaledBitmap(bitmap, 50, 50, true); friendPics.setImageBitmap(bitmap); }else{ friendPics.setImageResource(R.drawable.avatar); } img_availabiliy.setVisibility(View.VISIBLE); } return v; } @Override public int getChildrenCount(int groupPosition) { return childs.get(groupPosition).size(); } @Override public Object getGroup(int groupPosition) { return groups.get(groupPosition); } @Override public int getGroupCount() { return groups.size(); } @Override public long getGroupId(int groupPosition) { return (long) (groupPosition * 1024); } @Override public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) { View v = null; if (convertView != null) v = convertView; else v = inflater.inflate(R.layout.group_layout, parent, false); String gt = (String) getGroup(groupPosition); TextView tv2 = (TextView) v.findViewById(R.id.tvGroup); if (gt != null) tv2.setText(gt); /**Set Image on group layout, Max/min*/ View ind = v.findViewById( R.id.explist_indicator); View groupInd = v.findViewById( R.id.llgroup); if( ind != null ) { ImageView indicator = (ImageView)ind; if( getChildrenCount( groupPosition ) == 0 ) { indicator.setVisibility( View.INVISIBLE ); } else { indicator.setVisibility( View.VISIBLE ); int stateSetIndex = ( isExpanded ? 1 : 0) ; Drawable drawable = indicator.getDrawable(); drawable.setState(GROUP_STATE_SETS[stateSetIndex]); } } if( groupInd != null ) { RelativeLayout indicator2 = (RelativeLayout)groupInd; if( getChildrenCount( groupPosition ) == 0 ) { indicator2.setVisibility( View.INVISIBLE ); } else { indicator2.setVisibility( View.VISIBLE ); int stateSetIndex = ( isExpanded ? 1 : 0) ; Drawable drawable2 = indicator2.getBackground(); drawable2.setState(GROUP_STATE_SETS[stateSetIndex]); } } return v; } @Override public boolean hasStableIds() { return true; } @Override public boolean isChildSelectable(int groupPosition, int childPosition) { return true; } public void onGroupCollapsed(int groupPosition) { } public void onGroupExpanded(int groupPosition) { } } I just want to update my list in ON PRESENCE CHANGED method in the Service class.. Please suggest me a means to do the same.

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  • Modifying a HTML page to fix several "bugs" add a function to next/previous on a option dropdown

    - by Dennis Sylvian
    SOF, I've got a few problems plaguing me at the moment and am wondering if anyone could assist me with them. I'm trying to get Next Class | Previous Class to act as buttons so that when Next Class is clicked it will go to the next item in the dropdown list and for previous it would go to back one. There used to be a scroll bar that allowed me to scroll the main window left and right, it's missing because (I think it was to do with the scroll left and scroll right function) The footer at the bottom doesn't show correctly on mobile devices; for some reason it appears completely differently to as it does on a computer. The "bar" practically and the Scroll Left and Scroll buttons don't appear at all on mobile devices. The scroll left button is unable to be clicked for some reason, I'm unsure what I've done wrong. Refreshing the page resets the horizontal scroll position to far left (I'm pretty sure this relates to the scroll bar) I want to also find a way so that on mobile devices the the header will not show the placeholder image, however I can't work out what CSS media tag(s) I should be using. Latest: http://jsfiddle.net/pwv7u/ Smaller HTML <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>DATA DATA DATA DATA DATA DATA DATA DATA</title> <style type="text/css"> <!-- @import url("nstyle.css"); --> </style> <script src="jquery.min.js" type="text/javascript"></script> <script type="text/javascript"> $(document).ready( function() { for (var i=0;i<($("table").children().length);i++){ if(readCookie(i)) $($($("table").children()[i]).children()[(readCookie(i))]).toggleClass('selected').siblings().removeClass('selected'); } $("tr").click(function(){ $(this).toggleClass('selected').siblings().removeClass('selected'); if(readCookie($(this).parent().index())){ if(readCookie($(this).parent().index())==$(this).index()) eraseCookie($(this).parent().index()); else{ eraseCookie($(this).parent().index()); createCookie($(this).parent().index(),$(this).index(),1); } } else createCookie($(this).parent().index(),$(this).index(),1); }); // gather CLASS info var selector = $('.class-selector').on('change', function(){ var id = this.value; if (id!==''){ scrollToAnchor(id); } }); $('a[id^="CLASS"]').each(function(){ var id = this.id, option = $('<option>',{ value: this.id, text:this.id }); selector.append(option); }); function scrollToAnchor(aid) { var aTag = $("a[id='" + aid + "']"); $('html,body').animate({ scrollTop: aTag.offset().top - 80 }, 1); } $("a.TOPJS").click(function () { scrollToAnchor('TOP'); }); $("a.KEYJS").click(function () { scrollToAnchor('KEY'); }); $("a.def").click(function () { $('#container').animate({ "scrollLeft": "-=204" }, 200); }); $("a.abc").click(function () { $("#container").animate({ "scrollLeft": "+=204" }, 200); }); function createCookie(name,value,days) { var expires; if (days) { var date = new Date(); date.setMilliseconds(0); date.setSeconds(0); date.setMinutes(0); date.setHours(0); date.setDate(date.getDate()+days); expires = "; expires="+date.toGMTString(); } else expires = ""; document.cookie = name+"="+value+expires+"; path=/"; } function readCookie(name) { var nameEQ = name + "="; var ca = document.cookie.split(';'); for(var i=0;i < ca.length;i++) { var c = ca[i]; while (c.charAt(0)==' ') c = c.substring(1,c.length); if (c.indexOf(nameEQ) === 0) return c.substring(nameEQ.length,c.length); } return null; } function eraseCookie(name) { createCookie(name,"",-1); } }); </script> </head> <body> <div id="header_container"> <div id="header"> <a href="http://site.x/" target="_blank"><img src="http://placehold.it/300x80"></a> <select class="class-selector"> <option value="">-select class-</option> </select> <div class="classcycler"> <a href="#TOP"><font color=#EFEFEF>Next Class</font></a> <font color=red>|</font> <a href="#TOP"><font color=#EFEFEF>Previous Class</font></a> </div> <div id="header1"> Semi-Transparent Image <a href="#TOP"><font color=#EFEFEF>Up to Top</font></a> | <a href="#KEY"><font color=#EFEFEF>Down to Key</font></a> </div> </div> </div> <a id="TOP"></a> <div id="container"> <table id="gradient-style"> <tbody> <thead> <tr> <th scope="col"><a id="CLASS1"></a>Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class<br>Test 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class Data 1</th> <th scope="col">Class 1<br>Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1<br>Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1</th> <th scope="col">Class 1 Class 1</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> (data text)</th> <th scope="col">title text</th> <th scope="col">text</th> <th scope="col">text</th> <th scope="col">title text</th> <th scope="col">title text</th> </tr> </thead> <tr class="ft3"><td>testing data</td><td>testing data</td><td>test</td><td>class b</td><td>test4</td><td><div align="left">data</div></td><td><div align="left"> </div></td><td><div align="left"></div></td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>test</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><tr> <tr class="f3"><td>test</td><td>test</td><td>test</td><td>class a</td><td>test2</td><td><div align="left"> </div></td><td><div align="left"></div></td><td><div align="left"></div></td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>test</td><tr> <thead> <tr> <th scope="col"><a id="CLASS2"></a>Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class<br>Test 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class Data 2</th> <th scope="col">Class 2<br>Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2<br>Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2</th> <th scope="col">Class 2 Class 2</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> data text</th> <th scope="col">title text<br> (data text)</th> <th scope="col">title text</th> <th scope="col">text</th> <th scope="col">text</th> <th scope="col">title text</th> <th scope="col">title text</th> </tr> </thead> <tr class="ft3"><td>testing data</td><td>testing data</td><td>test</td><td>class f</td><td>test2</td><td><div align="left">data</div></td><td><div align="left"></div></td><td><div align="left">data</div></td><td>test</td><td>test</td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><tr> <tr><td>test</td><td>testing data</td><td>test</td><td>class f</td><td>test4</td><td><div align="left">data</div></td><td><div align="left"></div></td><td><div align="left"></div></td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><tr> <tr class="f3"><td>test</td><td>testing data</td><td>testing data</td><td>class d</td><td>test5</td><td><div align="left">data</div></td><td><div align="left"> </div></td><td><div align="left">data</div></td><td>test</td><td>test</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><tr> <tr><td>testing data</td><td>test</td><td>test</td><td>class f</td><td>test5</td><td><div align="left"></div></td><td><div align="left"></div></td><td><div align="left">data</div></td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>test</td><td>test</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>test</td><td>testing data</td><tr> <tr class="f2"><td>test</td><td>test</td><td>testing data</td><td>class a</td><td>test1</td><td><div align="left">data</div></td><td><div align="left"> </div></td><td><div align="left">data</div></td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>test</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>testing data</td><td>test</td><td>testing data</td><td>testing data</td><td>test</td><tr> </tbody> <tfoot> <tr> <th class="alt" colspan="34" scope="col"><a id="KEY"></a><img src="http://placehold.it/300x50"></th> </tr> <tr> <td colspan="34"><em><b>DATA DATA</b> - DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA </em></td> </tr> <tr> <td class="alt" colspan="34"><em><b>DAT DATA</b> - DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA DATA </em></td> </tr> </tfoot> </table> </div> <div id="footer_container"> <div id="footer"> <a href="http://site.x/" target="_blank"><img src="http://placehold.it/300x80"></a> <div class="footleft"> <a class="def" href="javascript: void(0);"><font color="#EFEFEF">Scroll Left</font></a> </div> <div id="footer1"> <font color="darkblue">Semi-Transparent Image</font> <i>Copyright &copy; 2013 <a href="http://site.x/" target="_blank" style="text-decoration: none"><font color=#ADD8E6>site</font></a>.</i> </div> <div id="footer2"> <i>All Rights Reserved.</i> </div> <div class="footright"> <a class="abc" href="javascript: void(0);"><font color="#EFEFEF">Scroll Right</font></a> </div> </div> </div> </body> </html> CSS gradient-style * { white-space: nowrap; } #header .class-selector { top: 10px; left: 20px; position: fixed; } #header .classcycler { top: 45px; left: 20px; position: fixed; font-size:20px; } body { line-height: 1.6em; background-color: #535353; overflow-x: scroll; } #gradient-style { font-family: "Lucida Sans Unicode", "Lucida Grande", Sans-Serif; font-size: 12px; margin: 0px; width: 100%; text-align: center; border-collapse: collapse; } #gradient-style th { font-size: 13px; font-weight: normal; line-height:250%; padding-left: 5px; padding-right: 5px; background: #535353 url('table-images/gradhead.png') repeat-x; border-top: 1px solid #fff; border-bottom: 1px solid #fff; color: #ffffff; } #gradient-style th.alt { font-family: "Times New Roman", Serif; text-align: left; padding: 10px; font-size: 26px; } #gradient-style td { padding-left: 5px; padding-right: 5px; border-bottom: 1px solid #fff; border-left: 1px solid #fff; border-right: 1px solid #fff; color: #00000; border-top: 1px solid #fff; background: #FFF url('table-images/gradback.png') repeat-x; } #gradient-style tr.ft3 td { color: #00000; background: #99cde7 url('table-images/gradoverallstudent.png') repeat-x; font-weight: bold; } #gradient-style tr.f1 td { color: #00000; background: #99cde7 url('table-images/gradbeststudent.png') repeat-x; } #gradient-style tr.f2 td { color: #00000; background: #b7e2b6 url('table-images/gradmostattentedstudent.png') repeat-x; } #gradient-style tr.f3 td { color: #00000; background: #a9cd6c url('table-images/gradleastlatestudtent.png') repeat-x; } #gradient-style tfoot tr td { background: #6FA275; font-size: 12px; color: #000; padding: 10; text-align: left; } #gradient-style tbody tr:hover td, #gradient-style tbody tr.selected td { background: #d0dafd url('table-images/gradhover.png') repeat-x; color: #339; } body { margin: 0; padding: 0; } #header_container { background: #000000 url('table-images/gradhead.png') repeat-x; border: 0px solid #666; height: 80px; left: 0; position: fixed; width: 100%; top: 0; } #header { position: relative; margin: 0 auto; width: 500px; height: 100%; text-align: center; color: #0c0aad; } #header1 { position: absolute; width: 125%; top: 50px; } #container { margin: 0 auto; overflow: auto; padding: 80px 0; width: 100%; } #content { } #footer_container { background: #000000 url('table-images/gradhead.png') repeat-x; border: 0px solid #666; bottom: 0; height: 95px; left: 0; position: fixed; width: 100%; } #footer { position: relative; margin: 0 auto; height: 100%; text-align: center; color: #FFF; } #footer1 { position: absolute; width: 103%; top: 50px; } #footer2 { position: absolute; width: 110%; top: 70px; } #footer .footleft { top: 45px; left: 2%; position: absolute; font-size:20px; } #footer .footright { top: 45px; right: 2%; position: absolute; font-size:20px; }

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  • What are good design practices when working with Entity Framework

    - by AD
    This will apply mostly for an asp.net application where the data is not accessed via soa. Meaning that you get access to the objects loaded from the framework, not Transfer Objects, although some recommendation still apply. This is a community post, so please add to it as you see fit. Applies to: Entity Framework 1.0 shipped with Visual Studio 2008 sp1. Why pick EF in the first place? Considering it is a young technology with plenty of problems (see below), it may be a hard sell to get on the EF bandwagon for your project. However, it is the technology Microsoft is pushing (at the expense of Linq2Sql, which is a subset of EF). In addition, you may not be satisfied with NHibernate or other solutions out there. Whatever the reasons, there are people out there (including me) working with EF and life is not bad.make you think. EF and inheritance The first big subject is inheritance. EF does support mapping for inherited classes that are persisted in 2 ways: table per class and table the hierarchy. The modeling is easy and there are no programming issues with that part. (The following applies to table per class model as I don't have experience with table per hierarchy, which is, anyway, limited.) The real problem comes when you are trying to run queries that include one or many objects that are part of an inheritance tree: the generated sql is incredibly awful, takes a long time to get parsed by the EF and takes a long time to execute as well. This is a real show stopper. Enough that EF should probably not be used with inheritance or as little as possible. Here is an example of how bad it was. My EF model had ~30 classes, ~10 of which were part of an inheritance tree. On running a query to get one item from the Base class, something as simple as Base.Get(id), the generated SQL was over 50,000 characters. Then when you are trying to return some Associations, it degenerates even more, going as far as throwing SQL exceptions about not being able to query more than 256 tables at once. Ok, this is bad, EF concept is to allow you to create your object structure without (or with as little as possible) consideration on the actual database implementation of your table. It completely fails at this. So, recommendations? Avoid inheritance if you can, the performance will be so much better. Use it sparingly where you have to. In my opinion, this makes EF a glorified sql-generation tool for querying, but there are still advantages to using it. And ways to implement mechanism that are similar to inheritance. Bypassing inheritance with Interfaces First thing to know with trying to get some kind of inheritance going with EF is that you cannot assign a non-EF-modeled class a base class. Don't even try it, it will get overwritten by the modeler. So what to do? You can use interfaces to enforce that classes implement some functionality. For example here is a IEntity interface that allow you to define Associations between EF entities where you don't know at design time what the type of the entity would be. public enum EntityTypes{ Unknown = -1, Dog = 0, Cat } public interface IEntity { int EntityID { get; } string Name { get; } Type EntityType { get; } } public partial class Dog : IEntity { // implement EntityID and Name which could actually be fields // from your EF model Type EntityType{ get{ return EntityTypes.Dog; } } } Using this IEntity, you can then work with undefined associations in other classes // lets take a class that you defined in your model. // that class has a mapping to the columns: PetID, PetType public partial class Person { public IEntity GetPet() { return IEntityController.Get(PetID,PetType); } } which makes use of some extension functions: public class IEntityController { static public IEntity Get(int id, EntityTypes type) { switch (type) { case EntityTypes.Dog: return Dog.Get(id); case EntityTypes.Cat: return Cat.Get(id); default: throw new Exception("Invalid EntityType"); } } } Not as neat as having plain inheritance, particularly considering you have to store the PetType in an extra database field, but considering the performance gains, I would not look back. It also cannot model one-to-many, many-to-many relationship, but with creative uses of 'Union' it could be made to work. Finally, it creates the side effet of loading data in a property/function of the object, which you need to be careful about. Using a clear naming convention like GetXYZ() helps in that regards. Compiled Queries Entity Framework performance is not as good as direct database access with ADO (obviously) or Linq2SQL. There are ways to improve it however, one of which is compiling your queries. The performance of a compiled query is similar to Linq2Sql. What is a compiled query? It is simply a query for which you tell the framework to keep the parsed tree in memory so it doesn't need to be regenerated the next time you run it. So the next run, you will save the time it takes to parse the tree. Do not discount that as it is a very costly operation that gets even worse with more complex queries. There are 2 ways to compile a query: creating an ObjectQuery with EntitySQL and using CompiledQuery.Compile() function. (Note that by using an EntityDataSource in your page, you will in fact be using ObjectQuery with EntitySQL, so that gets compiled and cached). An aside here in case you don't know what EntitySQL is. It is a string-based way of writing queries against the EF. Here is an example: "select value dog from Entities.DogSet as dog where dog.ID = @ID". The syntax is pretty similar to SQL syntax. You can also do pretty complex object manipulation, which is well explained [here][1]. Ok, so here is how to do it using ObjectQuery< string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); The first time you run this query, the framework will generate the expression tree and keep it in memory. So the next time it gets executed, you will save on that costly step. In that example EnablePlanCaching = true, which is unnecessary since that is the default option. The other way to compile a query for later use is the CompiledQuery.Compile method. This uses a delegate: static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => ctx.DogSet.FirstOrDefault(it => it.ID == id)); or using linq static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => (from dog in ctx.DogSet where dog.ID == id select dog).FirstOrDefault()); to call the query: query_GetDog.Invoke( YourContext, id ); The advantage of CompiledQuery is that the syntax of your query is checked at compile time, where as EntitySQL is not. However, there are other consideration... Includes Lets say you want to have the data for the dog owner to be returned by the query to avoid making 2 calls to the database. Easy to do, right? EntitySQL string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)).Include("Owner"); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); CompiledQuery static readonly Func<Entities, int, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, Dog>((ctx, id) => (from dog in ctx.DogSet.Include("Owner") where dog.ID == id select dog).FirstOrDefault()); Now, what if you want to have the Include parametrized? What I mean is that you want to have a single Get() function that is called from different pages that care about different relationships for the dog. One cares about the Owner, another about his FavoriteFood, another about his FavotireToy and so on. Basicly, you want to tell the query which associations to load. It is easy to do with EntitySQL public Dog Get(int id, string include) { string query = "select value dog " + "from Entities.DogSet as dog " + "where dog.ID = @ID"; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>(query, EntityContext.Instance)) .IncludeMany(include); oQuery.Parameters.Add(new ObjectParameter("ID", id)); oQuery.EnablePlanCaching = true; return oQuery.FirstOrDefault(); } The include simply uses the passed string. Easy enough. Note that it is possible to improve on the Include(string) function (that accepts only a single path) with an IncludeMany(string) that will let you pass a string of comma-separated associations to load. Look further in the extension section for this function. If we try to do it with CompiledQuery however, we run into numerous problems: The obvious static readonly Func<Entities, int, string, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, string, Dog>((ctx, id, include) => (from dog in ctx.DogSet.Include(include) where dog.ID == id select dog).FirstOrDefault()); will choke when called with: query_GetDog.Invoke( YourContext, id, "Owner,FavoriteFood" ); Because, as mentionned above, Include() only wants to see a single path in the string and here we are giving it 2: "Owner" and "FavoriteFood" (which is not to be confused with "Owner.FavoriteFood"!). Then, let's use IncludeMany(), which is an extension function static readonly Func<Entities, int, string, Dog> query_GetDog = CompiledQuery.Compile<Entities, int, string, Dog>((ctx, id, include) => (from dog in ctx.DogSet.IncludeMany(include) where dog.ID == id select dog).FirstOrDefault()); Wrong again, this time it is because the EF cannot parse IncludeMany because it is not part of the functions that is recognizes: it is an extension. Ok, so you want to pass an arbitrary number of paths to your function and Includes() only takes a single one. What to do? You could decide that you will never ever need more than, say 20 Includes, and pass each separated strings in a struct to CompiledQuery. But now the query looks like this: from dog in ctx.DogSet.Include(include1).Include(include2).Include(include3) .Include(include4).Include(include5).Include(include6) .[...].Include(include19).Include(include20) where dog.ID == id select dog which is awful as well. Ok, then, but wait a minute. Can't we return an ObjectQuery< with CompiledQuery? Then set the includes on that? Well, that what I would have thought so as well: static readonly Func<Entities, int, ObjectQuery<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, ObjectQuery<Dog>>((ctx, id) => (ObjectQuery<Dog>)(from dog in ctx.DogSet where dog.ID == id select dog)); public Dog GetDog( int id, string include ) { ObjectQuery<Dog> oQuery = query_GetDog(id); oQuery = oQuery.IncludeMany(include); return oQuery.FirstOrDefault; } That should have worked, except that when you call IncludeMany (or Include, Where, OrderBy...) you invalidate the cached compiled query because it is an entirely new one now! So, the expression tree needs to be reparsed and you get that performance hit again. So what is the solution? You simply cannot use CompiledQueries with parametrized Includes. Use EntitySQL instead. This doesn't mean that there aren't uses for CompiledQueries. It is great for localized queries that will always be called in the same context. Ideally CompiledQuery should always be used because the syntax is checked at compile time, but due to limitation, that's not possible. An example of use would be: you may want to have a page that queries which two dogs have the same favorite food, which is a bit narrow for a BusinessLayer function, so you put it in your page and know exactly what type of includes are required. Passing more than 3 parameters to a CompiledQuery Func is limited to 5 parameters, of which the last one is the return type and the first one is your Entities object from the model. So that leaves you with 3 parameters. A pitance, but it can be improved on very easily. public struct MyParams { public string param1; public int param2; public DateTime param3; } static readonly Func<Entities, MyParams, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, MyParams, IEnumerable<Dog>>((ctx, myParams) => from dog in ctx.DogSet where dog.Age == myParams.param2 && dog.Name == myParams.param1 and dog.BirthDate > myParams.param3 select dog); public List<Dog> GetSomeDogs( int age, string Name, DateTime birthDate ) { MyParams myParams = new MyParams(); myParams.param1 = name; myParams.param2 = age; myParams.param3 = birthDate; return query_GetDog(YourContext,myParams).ToList(); } Return Types (this does not apply to EntitySQL queries as they aren't compiled at the same time during execution as the CompiledQuery method) Working with Linq, you usually don't force the execution of the query until the very last moment, in case some other functions downstream wants to change the query in some way: static readonly Func<Entities, int, string, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, IEnumerable<Dog>>((ctx, age, name) => from dog in ctx.DogSet where dog.Age == age && dog.Name == name select dog); public IEnumerable<Dog> GetSomeDogs( int age, string name ) { return query_GetDog(YourContext,age,name); } public void DataBindStuff() { IEnumerable<Dog> dogs = GetSomeDogs(4,"Bud"); // but I want the dogs ordered by BirthDate gridView.DataSource = dogs.OrderBy( it => it.BirthDate ); } What is going to happen here? By still playing with the original ObjectQuery (that is the actual return type of the Linq statement, which implements IEnumerable), it will invalidate the compiled query and be force to re-parse. So, the rule of thumb is to return a List< of objects instead. static readonly Func<Entities, int, string, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, int, string, IEnumerable<Dog>>((ctx, age, name) => from dog in ctx.DogSet where dog.Age == age && dog.Name == name select dog); public List<Dog> GetSomeDogs( int age, string name ) { return query_GetDog(YourContext,age,name).ToList(); //<== change here } public void DataBindStuff() { List<Dog> dogs = GetSomeDogs(4,"Bud"); // but I want the dogs ordered by BirthDate gridView.DataSource = dogs.OrderBy( it => it.BirthDate ); } When you call ToList(), the query gets executed as per the compiled query and then, later, the OrderBy is executed against the objects in memory. It may be a little bit slower, but I'm not even sure. One sure thing is that you have no worries about mis-handling the ObjectQuery and invalidating the compiled query plan. Once again, that is not a blanket statement. ToList() is a defensive programming trick, but if you have a valid reason not to use ToList(), go ahead. There are many cases in which you would want to refine the query before executing it. Performance What is the performance impact of compiling a query? It can actually be fairly large. A rule of thumb is that compiling and caching the query for reuse takes at least double the time of simply executing it without caching. For complex queries (read inherirante), I have seen upwards to 10 seconds. So, the first time a pre-compiled query gets called, you get a performance hit. After that first hit, performance is noticeably better than the same non-pre-compiled query. Practically the same as Linq2Sql When you load a page with pre-compiled queries the first time you will get a hit. It will load in maybe 5-15 seconds (obviously more than one pre-compiled queries will end up being called), while subsequent loads will take less than 300ms. Dramatic difference, and it is up to you to decide if it is ok for your first user to take a hit or you want a script to call your pages to force a compilation of the queries. Can this query be cached? { Dog dog = from dog in YourContext.DogSet where dog.ID == id select dog; } No, ad-hoc Linq queries are not cached and you will incur the cost of generating the tree every single time you call it. Parametrized Queries Most search capabilities involve heavily parametrized queries. There are even libraries available that will let you build a parametrized query out of lamba expressions. The problem is that you cannot use pre-compiled queries with those. One way around that is to map out all the possible criteria in the query and flag which one you want to use: public struct MyParams { public string name; public bool checkName; public int age; public bool checkAge; } static readonly Func<Entities, MyParams, IEnumerable<Dog>> query_GetDog = CompiledQuery.Compile<Entities, MyParams, IEnumerable<Dog>>((ctx, myParams) => from dog in ctx.DogSet where (myParams.checkAge == true && dog.Age == myParams.age) && (myParams.checkName == true && dog.Name == myParams.name ) select dog); protected List<Dog> GetSomeDogs() { MyParams myParams = new MyParams(); myParams.name = "Bud"; myParams.checkName = true; myParams.age = 0; myParams.checkAge = false; return query_GetDog(YourContext,myParams).ToList(); } The advantage here is that you get all the benifits of a pre-compiled quert. The disadvantages are that you most likely will end up with a where clause that is pretty difficult to maintain, that you will incur a bigger penalty for pre-compiling the query and that each query you run is not as efficient as it could be (particularly with joins thrown in). Another way is to build an EntitySQL query piece by piece, like we all did with SQL. protected List<Dod> GetSomeDogs( string name, int age) { string query = "select value dog from Entities.DogSet where 1 = 1 "; if( !String.IsNullOrEmpty(name) ) query = query + " and dog.Name == @Name "; if( age > 0 ) query = query + " and dog.Age == @Age "; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>( query, YourContext ); if( !String.IsNullOrEmpty(name) ) oQuery.Parameters.Add( new ObjectParameter( "Name", name ) ); if( age > 0 ) oQuery.Parameters.Add( new ObjectParameter( "Age", age ) ); return oQuery.ToList(); } Here the problems are: - there is no syntax checking during compilation - each different combination of parameters generate a different query which will need to be pre-compiled when it is first run. In this case, there are only 4 different possible queries (no params, age-only, name-only and both params), but you can see that there can be way more with a normal world search. - Noone likes to concatenate strings! Another option is to query a large subset of the data and then narrow it down in memory. This is particularly useful if you are working with a definite subset of the data, like all the dogs in a city. You know there are a lot but you also know there aren't that many... so your CityDog search page can load all the dogs for the city in memory, which is a single pre-compiled query and then refine the results protected List<Dod> GetSomeDogs( string name, int age, string city) { string query = "select value dog from Entities.DogSet where dog.Owner.Address.City == @City "; ObjectQuery<Dog> oQuery = new ObjectQuery<Dog>( query, YourContext ); oQuery.Parameters.Add( new ObjectParameter( "City", city ) ); List<Dog> dogs = oQuery.ToList(); if( !String.IsNullOrEmpty(name) ) dogs = dogs.Where( it => it.Name == name ); if( age > 0 ) dogs = dogs.Where( it => it.Age == age ); return dogs; } It is particularly useful when you start displaying all the data then allow for filtering. Problems: - Could lead to serious data transfer if you are not careful about your subset. - You can only filter on the data that you returned. It means that if you don't return the Dog.Owner association, you will not be able to filter on the Dog.Owner.Name So what is the best solution? There isn't any. You need to pick the solution that works best for you and your problem: - Use lambda-based query building when you don't care about pre-compiling your queries. - Use fully-defined pre-compiled Linq query when your object structure is not too complex. - Use EntitySQL/string concatenation when the structure could be complex and when the possible number of different resulting queries are small (which means fewer pre-compilation hits). - Use in-memory filtering when you are working with a smallish subset of the data or when you had to fetch all of the data on the data at first anyway (if the performance is fine with all the data, then filtering in memory will not cause any time to be spent in the db). Singleton access The best way to deal with your context and entities accross all your pages is to use the singleton pattern: public sealed class YourContext { private const string instanceKey = "On3GoModelKey"; YourContext(){} public static YourEntities Instance { get { HttpContext context = HttpContext.Current; if( context == null ) return Nested.instance; if (context.Items[instanceKey] == null) { On3GoEntities entity = new On3GoEntities(); context.Items[instanceKey] = entity; } return (YourEntities)context.Items[instanceKey]; } } class Nested { // Explicit static constructor to tell C# compiler // not to mark type as beforefieldinit static Nested() { } internal static readonly YourEntities instance = new YourEntities(); } } NoTracking, is it worth it? When executing a query, you can tell the framework to track the objects it will return or not. What does it mean? With tracking enabled (the default option), the framework will track what is going on with the object (has it been modified? Created? Deleted?) and will also link objects together, when further queries are made from the database, which is what is of interest here. For example, lets assume that Dog with ID == 2 has an owner which ID == 10. Dog dog = (from dog in YourContext.DogSet where dog.ID == 2 select dog).FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; Person owner = (from o in YourContext.PersonSet where o.ID == 10 select dog).FirstOrDefault(); //dog.OwnerReference.IsLoaded == true; If we were to do the same with no tracking, the result would be different. ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>) (from dog in YourContext.DogSet where dog.ID == 2 select dog); oDogQuery.MergeOption = MergeOption.NoTracking; Dog dog = oDogQuery.FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; ObjectQuery<Person> oPersonQuery = (ObjectQuery<Person>) (from o in YourContext.PersonSet where o.ID == 10 select o); oPersonQuery.MergeOption = MergeOption.NoTracking; Owner owner = oPersonQuery.FirstOrDefault(); //dog.OwnerReference.IsLoaded == false; Tracking is very useful and in a perfect world without performance issue, it would always be on. But in this world, there is a price for it, in terms of performance. So, should you use NoTracking to speed things up? It depends on what you are planning to use the data for. Is there any chance that the data your query with NoTracking can be used to make update/insert/delete in the database? If so, don't use NoTracking because associations are not tracked and will causes exceptions to be thrown. In a page where there are absolutly no updates to the database, you can use NoTracking. Mixing tracking and NoTracking is possible, but it requires you to be extra careful with updates/inserts/deletes. The problem is that if you mix then you risk having the framework trying to Attach() a NoTracking object to the context where another copy of the same object exist with tracking on. Basicly, what I am saying is that Dog dog1 = (from dog in YourContext.DogSet where dog.ID == 2).FirstOrDefault(); ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>) (from dog in YourContext.DogSet where dog.ID == 2 select dog); oDogQuery.MergeOption = MergeOption.NoTracking; Dog dog2 = oDogQuery.FirstOrDefault(); dog1 and dog2 are 2 different objects, one tracked and one not. Using the detached object in an update/insert will force an Attach() that will say "Wait a minute, I do already have an object here with the same database key. Fail". And when you Attach() one object, all of its hierarchy gets attached as well, causing problems everywhere. Be extra careful. How much faster is it with NoTracking It depends on the queries. Some are much more succeptible to tracking than other. I don't have a fast an easy rule for it, but it helps. So I should use NoTracking everywhere then? Not exactly. There are some advantages to tracking object. The first one is that the object is cached, so subsequent call for that object will not hit the database. That cache is only valid for the lifetime of the YourEntities object, which, if you use the singleton code above, is the same as the page lifetime. One page request == one YourEntity object. So for multiple calls for the same object, it will load only once per page request. (Other caching mechanism could extend that). What happens when you are using NoTracking and try to load the same object multiple times? The database will be queried each time, so there is an impact there. How often do/should you call for the same object during a single page request? As little as possible of course, but it does happens. Also remember the piece above about having the associations connected automatically for your? You don't have that with NoTracking, so if you load your data in multiple batches, you will not have a link to between them: ObjectQuery<Dog> oDogQuery = (ObjectQuery<Dog>)(from dog in YourContext.DogSet select dog); oDogQuery.MergeOption = MergeOption.NoTracking; List<Dog> dogs = oDogQuery.ToList(); ObjectQuery<Person> oPersonQuery = (ObjectQuery<Person>)(from o in YourContext.PersonSet select o); oPersonQuery.MergeOption = MergeOption.NoTracking; List<Person> owners = oPersonQuery.ToList(); In this case, no dog will have its .Owner property set. Some things to keep in mind when you are trying to optimize the performance. No lazy loading, what am I to do? This can be seen as a blessing in disguise. Of course it is annoying to load everything manually. However, it decreases the number of calls to the db and forces you to think about when you should load data. The more you can load in one database call the better. That was always true, but it is enforced now with this 'feature' of EF. Of course, you can call if( !ObjectReference.IsLoaded ) ObjectReference.Load(); if you want to, but a better practice is to force the framework to load the objects you know you will need in one shot. This is where the discussion about parametrized Includes begins to make sense. Lets say you have you Dog object public class Dog { public Dog Get(int id) { return YourContext.DogSet.FirstOrDefault(it => it.ID == id ); } } This is the type of function you work with all the time. It gets called from all over the place and once you have that Dog object, you will do very different things to it in different functions. First, it should be pre-compiled, because you will call that very often. Second, each different pages will want to have access to a different subset of the Dog data. Some will want the Owner, some the FavoriteToy, etc. Of course, you could call Load() for each reference you need anytime you need one. But that will generate a call to the database each time. Bad idea. So instead, each page will ask for the data it wants to see when it first request for the Dog object: static public Dog Get(int id) { return GetDog(entity,"");} static public Dog Get(int id, string includePath) { string query = "select value o " + " from YourEntities.DogSet as o " +

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