如何使用 NSXMLParser 获取 DTD 的公共 ID 和系统 ID

发布于 2024-09-14 05:49:31 字数 1061 浏览 2 评论 0原文

我正在尝试通过 NSXMLParser 检索 XML 文档中 DTD 的公共 ID 和系统 ID。虽然 NSXMLParser 主要提供 publicID 和 systemID 选择器，但它们似乎不适合我。 doctype 标记如下所示：

<!DOCTYPE Article PUBLIC "-//SoftQuad Software//DTD Journalist v2.0 20000501//EN" "file:///C:/Program%20Files/Corel/XMetaL%204/Author/Rules/journalist.dtd">

这是我的代码（该文件是通过 NSFileHandle 的 readDataToEndOfFile 打开的：

NSXMLParser *parser = [[NSXMLParser alloc] initWithData:data];
[parser setDelegate:self];
BOOL parseSuccessful = [parser parse];

在委托的 parserDidStartDocument: 中，我尝试访问ID：

NSLog(@"%@ : %@", [parser publicID], [parser systemID]);

看到

(null) : (null)

但我只从文档中

：
一旦解析操作开始或发生错误后，您可以调用此方法。

所以我认为这应该已经在 parserDidStartDocument: 中工作，但我尝试在不同的委托方法中调用这些选择器（例如 parser:didStartElement:namespaceURI:qualifiedName:attributes: 但是没有成功。

有什么想法我做错了吗？

原文

I'm trying to retrieve the public and system IDs for a DTD in an XML document via NSXMLParser. While NSXMLParser in principal offers publicID and systemID selectors they don't seem to work for me. The doctype tag looks like this:

<!DOCTYPE Article PUBLIC "-//SoftQuad Software//DTD Journalist v2.0 20000501//EN" "file:///C:/Program%20Files/Corel/XMetaL%204/Author/Rules/journalist.dtd">

Here's my code (the file was opened via NSFileHandle's readDataToEndOfFile:

NSXMLParser *parser = [[NSXMLParser alloc] initWithData:data];
[parser setDelegate:self];
BOOL parseSuccessful = [parser parse];

In the delegate's parserDidStartDocument: I try to access the IDs:

NSLog(@"%@ : %@", [parser publicID], [parser systemID]);

But I only see

(null) : (null)

From the documentation:

You may invoke this method once a parsing operation has begun or after an error occurs.

So I'd think this should work already in parserDidStartDocument: but I tried to call these selectors in different delegate methods (like parser:didStartElement:namespaceURI:qualifiedName:attributes: but without success.

Any ideas what I'm doing wrong?

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