While trying to Generate MetadataService classes using the standard Metadata API WSDL from Salesforce, classes I got below error. I think it is related to the length of the Apex class as the lines of code in MetadataService class are more than 13K.
I downloaded the WSDL file from Setup -> API -> Generate Metadata WSDL
Error: Script too large: public class MetadataService { public class ReportTypeColumnTranslation { public Strin... at 3:14
The Enterprise and Partner APIs are intended for usage outside of Salesforce rather than integrating two Salesforce Orgs together. They are typically consumed by languages like Java, .NET, PHP, Ruby, ...
As you found, anyType is not supported by Wsdl2Apex. See Supported WSDL Features:
The Salesforce datatype anyType is not supported in WSDLs used to generate Apex code that is saved using API version 15.0 and later. For code saved using API version 14.0 and earlier, anyType is mapped to String.
So in earlier versions anyType was mapped to string. You can certainly change it in the WSDL element types to get WSDL2Apex to import it.
It appears to only be used on the NewValue and OldValue elements on History Types. E.g. from AccountHistory.
<element name="NewValue" nillable="true" minOccurs="0" type="xsd:anyType"/>
<element name="OldValue" nillable="true" minOccurs="0" type="xsd:anyType"/>
If you aren't going to be working with these History sObjects then you aren't likely to have any issues with the change.
Alternatives:
There are three separate issues here:
I'm going to largely skip over 1 and 2 for now other than saying that the Enterprise WSDL isn't really intended for consumption within Salesforce. This would be better addressed in the question Can we create report folders through Apex.
I've been working with an intern on a tool that will generate Apex for calling a WSDL. Part of this process is giving you control over which methods from the web service ultimately get generated in Apex.
With the Enterprise WSDL, you may only want to generate several of the 45 available methods.
Reducing the number of methods reduces the size of the generated apex class and reduces the number of methods you need to have covered by test cases.
If you are keen to try it, download the latest version of the FuseIT SFDC Explorer. There is a tab along the top called WSDL2Apex that will start the process off.
After defining the Apex class names for each namespace in the WSDL, you can pick and choose which methods will be generated in Apex:
One other benefit here is that you can generate basic tests and mock classes to give you coverage for the generated code.
Note that you many still need to remove some of the generated inner classes that aren't required.
Best Answer
When I've wanted to invoke this API from Apex in the past I have used this already generated and modified code:
Apex Wrapper Salesforce Metadata API
though it looks like it hasn't have much attention in recent years. It does support at least this version of the API:
and probably v42.0 based on commit comments.
The list of changes it applies to make the API work from apex is listed here MetadataServicePatcher.cls line 28, though no mention of the class size limit being hit. But additions to the WSDL since v37/v42 may be causing that.
The Tooling API can be accessed via JSON REST calls so does not require any generated code to use. If the operation you want to invoke is present in that API, it is a lot easier to use.