iska
12276e91b3
The tree visitor walks the DOM in tree order and calls the provided node visitor upon entring and leaving a node.
64 lines
1.2 KiB
Objective-C
64 lines
1.2 KiB
Objective-C
//
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// HTMLTreeVisitor.m
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// HTMLKit
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//
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// Created by Iska on 30.07.19.
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// Copyright © 2019 BrainCookie. All rights reserved.
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//
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#import "HTMLTreeVisitor.h"
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#import "HTMLNode.h"
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#import "HTMLTreeWalker.h"
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@interface HTMLTreeVisitor()
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{
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HTMLNode *_root;
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HTMLTreeWalker *_treeWalker;
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}
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@end
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@implementation HTMLTreeVisitor
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- (instancetype)initWithNode:(HTMLNode *)node
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{
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self = [super init];
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if (self) {
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_root = node;
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_treeWalker = [[HTMLTreeWalker alloc] initWithNode:node];
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}
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return self;
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}
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- (void)walkWithNodeVisitor:(id<HTMLNodeVisitor>)visitor
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{
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HTMLNode *currentNode = _treeWalker.currentNode;
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while (currentNode) {
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[visitor enter:currentNode];
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if (currentNode.hasChildNodes) {
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currentNode = [_treeWalker firstChild];
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continue;
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}
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HTMLNode *next = [_treeWalker nextSibling];
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if (next) {
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[visitor leave:currentNode];
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currentNode = next;
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continue;
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}
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while (!next && _treeWalker.currentNode != _root) {
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[visitor leave:_treeWalker.currentNode];
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currentNode = [_treeWalker parentNode];
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next = [_treeWalker nextSibling];
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}
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[visitor leave:currentNode];
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currentNode = _treeWalker.currentNode;
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if (currentNode == _root) {
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break;
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}
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}
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}
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@end
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