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May 10, 2015 21:49
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An object which builds HTML code for subsequent use in a UIWebView. The HTML code is always valid as elements are created and closed automatically as required.
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| // | |
| // HTMLBuilder.swift | |
| // | |
| // Created by Karl Wilcox on 16/03/2015. | |
| // Copyright (c) 2015 Karl Wilcox. All rights reserved. | |
| // | |
| import Foundation | |
| /// Builds and returns valid HTML for use in UIWebView | |
| /* Example Usage: | |
| * let page = HTMLBuilder() | |
| * page.stylesheet = "stylesheet.css" | |
| * page.startDiv("content") | |
| * page.AddHeading("A Heading") | |
| * page.addPlainText("The content is always valid HTML") | |
| * page.addListItem("item 1") | |
| * page.addListItem("item 2") | |
| * let stringForUIWebView = page.HTMLasString | |
| */ | |
| class HTMLBuilder { | |
| /* public type for specifying the list */ | |
| enum listType { case none, bullet, numbered } | |
| /* private vars to track what state the HTML is in */ | |
| private var content:String = "" | |
| private var inParagraph = false | |
| private var inList = listType.none | |
| private var divStack:[String] = [] | |
| private var newLine = "" | |
| /// prettyPrint boolean, use newlines | |
| var prettyPrint:Bool = false { | |
| didSet { | |
| if prettyPrint == true { | |
| newLine = "\n" | |
| } else { | |
| newLine = "" | |
| } | |
| } | |
| } | |
| /// stylesheetName the basename (without .css) of the required stylesheet | |
| var stylesheetName:String = "" { | |
| didSet { | |
| if stylesheetName != "" { | |
| stylesheetName = "<link type=\"text/css\" rel=\"stylesheet\" href=\"\(stylesheetName).css\"/>\(newLine)" | |
| } | |
| } | |
| } | |
| /// paragraphClassAttribute sets class attribute of subsequently added paragraphs | |
| var paragraphClassAttribute:String = "" { | |
| didSet { | |
| if paragraphClassAttribute != "" { | |
| paragraphClassAttribute = " class=\"\(paragraphClassAttribute)\" " | |
| } | |
| } | |
| } | |
| /// listClassAttribute sets class attribute of subsequently added list (<ol> or <ul>) | |
| var listClassAttribute:String = "" { | |
| didSet { | |
| if listClassAttribute != "" { | |
| listClassAttribute = " class=\"\(listClassAttribute)\" " | |
| } | |
| } | |
| } | |
| /// rawHTML returns the actual code, and then deletes contents, allowing re-use with new content | |
| var HTMLasString:String { | |
| addMatchingCloseIfNeeded() | |
| while divStack.count > 0 { | |
| endDiv() | |
| } | |
| let valueToReturn = "<head>\(newLine)\(stylesheetName)</head>\(newLine)<body>\(newLine)\(content)</body>\(newLine)" | |
| content = "" // makes it a reusable object | |
| return valueToReturn | |
| } | |
| private func addMatchingCloseIfNeeded() { | |
| if inList == .bullet { | |
| content += "</ul>\(newLine)" | |
| inList = .none | |
| } else if inList == .numbered { | |
| content += "</ol>\(newLine)" | |
| inList = .none | |
| } else if inParagraph { | |
| content += "</p>\(newLine)" | |
| inParagraph = false | |
| } | |
| } | |
| private func addStartParaIfNeeded() { | |
| if !inParagraph { | |
| content += "<p\(paragraphClassAttribute)>" | |
| inParagraph = true | |
| } | |
| } | |
| private func escapeHTMLCharacters(var text:String) ->String { | |
| let replacements = ["&", "&", // This MUST be first! | |
| "\"", """, | |
| "'", "'", | |
| "<", "<", | |
| ">", ">" | |
| ] | |
| for i in stride(from: 0, to: replacements.count, by: 2) { | |
| text = text.stringByReplacingOccurrencesOfString(replacements[i], withString: replacements[i+1], options: nil, range: nil) | |
| } | |
| return text | |
| } | |
| /// Adds a heading to the HTML, of any level, with an optional class | |
| /// | |
| /// :param: title The text content of the heading | |
| /// :param: headingClass? value of class attribute to, or nil for no attribute at all | |
| /// :param: level heading level (digit only, 1 to 5 allowed) | |
| func addHeading(title:String, headingClass:String? = nil, var level:Int = 1) { | |
| var classAttribute = "" | |
| level = min(5,max(1,level)) | |
| addMatchingCloseIfNeeded() | |
| if headingClass != nil && headingClass! != "" { | |
| classAttribute = " class=\"\(headingClass!)\" " | |
| } | |
| content += "<h\(level)\(classAttribute)>\(escapeHTMLCharacters(title))</h\(level)>\(newLine)" | |
| } | |
| /// Starts a new paragraph. Only needed if already in a paragraph | |
| func newParagraph() { | |
| addMatchingCloseIfNeeded() | |
| content += "<p\(paragraphClassAttribute)>" | |
| } | |
| /// Adds just plain text to the current paragraph, escaping HTML characters as required | |
| /// The current class attribute will be added, if set | |
| /// | |
| /// :param: text the text to be added, any embedded HTML will be escaped! | |
| func addPlainText(text:String) { | |
| addStartParaIfNeeded() | |
| content += escapeHTMLCharacters(text) + " " | |
| } | |
| /// inserts raw HTML - use with care!!! | |
| func addInnerHTML(text:String) { | |
| content += text | |
| } | |
| /// Adds bold text to the current paragraph, escaping HTML characters as required | |
| /// | |
| /// :param: text the text to be added, any embedded HTML will be escaped! | |
| func addBoldText(text:String) { | |
| addStartParaIfNeeded() | |
| content += "<strong>\(escapeHTMLCharacters(text))</strong> " | |
| } | |
| /// Adds italic text to the current paragraph, escaping HTML characters as required | |
| /// | |
| /// :param: text the text to be added, any embedded HTML will be escaped! | |
| func addItalicText(text:String) { | |
| addStartParaIfNeeded() | |
| content += "<em>\(escapeHTMLCharacters(text))</em> " | |
| } | |
| /// Adds a link to the current paragraph, with optional link text | |
| /// | |
| /// :param: url a URL string, which will be properly encoded so may contain spaces etc. | |
| /// :param: text optional string, if present will be used as the link text instead of the URL | |
| func addLink(url:String, text:String? = nil) { | |
| addStartParaIfNeeded() | |
| content += "<a href=\"\(url.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!)\"> " | |
| if text != nil && text! != "" { | |
| content += escapeHTMLCharacters(text!) | |
| } else { | |
| content += escapeHTMLCharacters(url) | |
| } | |
| content += "</a>" | |
| } | |
| /// Adds a list item of a given type, ending paragraph and starting list if necessary | |
| /// | |
| /// :param: text the contain of the list item (sorry, plain text only at the moment) | |
| /// :param: type optional, set to .bullet (the default) or .numbered, if .none or missing, continue same | |
| func addListItem(text:String, type:listType = .none) { | |
| if inParagraph { | |
| content += "</p>\(newLine)" | |
| inParagraph = false | |
| } | |
| switch inList { | |
| case .none: // not in any list, so start a new one | |
| if type == .numbered { | |
| content += "<ol\(listClassAttribute)>\(newLine)" | |
| inList = .numbered | |
| } else { // wether it is .none or .bullet, go with bulleted | |
| content += "<ul\(listClassAttribute)>\(newLine)" | |
| inList = .bullet | |
| } | |
| case .bullet: // already in a bullet, change if different type | |
| if type == .numbered { | |
| content += "</ul><ol\(listClassAttribute)>\(newLine)" | |
| inList = .numbered | |
| } | |
| case .numbered: // already in a numbered list, change if different type | |
| if type == .bullet { | |
| content += "</ol><ul\(listClassAttribute)>\(newLine)" | |
| inList = .bullet | |
| } | |
| } | |
| // Now add the list item | |
| content += "<li>\(escapeHTMLCharacters(text))</li>\(newLine)" | |
| } | |
| /// Adds an image, ending paragraph or list as necessary (images are on their own) | |
| /// | |
| /// :param: url location of the image, will be properly encoded | |
| /// :param: imageClass optional string will be set as the value of the class attribute | |
| /// :param: width optional string, used as value of width attribute | |
| /// :param: height optional string used as value of height attribute | |
| func addImage(url: String, imageClass:String? = nil, width:String? = nil, height:String? = nil) { | |
| var widthAttribute = "" | |
| var heightAttribute = "" | |
| var classAttribute = "" | |
| addMatchingCloseIfNeeded() | |
| if imageClass != nil && imageClass! != "" { | |
| classAttribute = " class=\"\(imageClass!)\" " | |
| } | |
| if width != nil && width! != "" { | |
| widthAttribute = " width=\"\(width!)\" " | |
| } | |
| if height != nil && height! != "" { | |
| heightAttribute = " height=\"\(height!)\" " | |
| } | |
| content += "<img\(classAttribute) src=\"\(url.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!)\"\(widthAttribute)\(heightAttribute)/>\(newLine)" | |
| } | |
| private var dummyID = 1 | |
| /// Starts a div, with an optional class and enforced ID, closing any paras or lists first | |
| /// | |
| /// :param: divID optional ID, if nil a dummy unique value will be used | |
| /// :param: classAttribute optional string used as value of class attribute | |
| func startDiv(divID:String?, divClass:String? = nil) { | |
| var idValue = "" | |
| var classAttribute = "" | |
| addMatchingCloseIfNeeded() // can't start divs in paragraphs or lists | |
| if divID == nil { | |
| idValue = "div\(dummyID)" | |
| dummyID += 1 | |
| } else { | |
| idValue = divID! | |
| } | |
| divStack.append(idValue) | |
| if divClass != nil && divClass != "" { | |
| classAttribute = " class=\"\(divClass!)\" " | |
| } | |
| content += "<div id=\"\(idValue)\"\(classAttribute)>\(newLine)" | |
| } | |
| /// ends the most recent div, harmless if no existing div | |
| func endDiv() { | |
| if divStack.count > 0 { | |
| addMatchingCloseIfNeeded() // must end paragraph or list before ending div | |
| if prettyPrint { | |
| content += "<!-- \(divStack.last) -->" | |
| } | |
| content += "</div>\(newLine)" | |
| divStack.removeLast() | |
| } | |
| } | |
| func printRaw() { | |
| println(content) | |
| } | |
| } |
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