Haskell HXT: Parsing xml documents with remote DTD without hxt-curl

5
votes

I'm trying to parse the following XML document with HXT:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Key</key>
    <string>Value</string>
</dict>
</plist>

I don't want any validation here since it will require network access. Unfortunately, HXT still wants hxt-curl / hxt-http packages installed to parse this simple document:

Prelude> :m +Text.XML.HXT.Core
Prelude Text.XML.HXT.Core> runX $ readDocument [withValidate no] "example.xml"

fatal error: HTTP handler not configured,
please install package hxt-curl and use 'withCurl' config option
or install package hxt-http and use 'withHTTP' config option

I don't want to add hxt-curl/hxt-http packages to the list of dependencies since I don't really need them. I can't change the documents I'm parsing. Moving to another xml parsing library is also undesirable.

Is there a way to parse the sample document with HXT without adding unnecessary packages?

1
haskellhxt

1 Answers

6
votes

You have also to declare withSubstDTDEntities no, i. e.

runX $ readDocument [withValidate no, withSubstDTDEntities no] "example.xml"

Explanation: The default for this config is yes and I guess that's why hxt tries to download the dtd file. From the documentation:

Switching this option and the validation off can lead to faster parsing, in that case reading the DTD documents is not longer necessary.