Doc->Bug #78749 [Ver]: Wrong error message when maxOccurs is exceeded

Edit report at https://bugs.php.net/bug.php?id=78749&edit=1 ID: 78749 User updated by: tony at marston-home dot demon dot co dot uk Reported by: tony at marston-home dot demon dot co dot uk -Summary: No comprehensive documentation on how SoapClient serializes data per the WSDL +Summary: Wrong error message when maxOccurs is exceeded Status: Verified -Type: Documentation Problem +Type: Bug Package: SOAP related Operating System: Windows 10 PHP Version: 7.3.11 Block user comment: N Private report: N New Comment: This is NOT a documentation error as your implementation clearly does NOT follow the WSDL specification. Previous Comments: ------------------------------------------------------------------------ [2019-11-06 10:23:09] tony at marston-home dot demon dot co dot uk You may not be familiar with my use of a <contacts> element which is a container for 1 or more <contact> elements, but if you look at the example XML document in http://www.w3.org/TR/xmlschema-0/#PO you will see that it has an <items> element which is a container for one or more <item> elements. The <items> element has an implied maxOccurs of 1, and in my test data my <contacts> element has an explicit maxOccurs of 1. The <item> element has a maxOccurs of "unbounded", and in my test data my <contact> element has a specified limit, and I am testing to see what happens if the limit is exceeded when I supply 3 occurrences. If the maxOccurs value is 1 the error message is wrong. If the maxOccurs value is 2 there is no error message. You said in your reply that "Currently PHP only really cares if maxOccurs>1 or not." This is clearly wrong. The WSDL specification clearly states that the maxOccurs value defines "The maximum number of times an element may appear" and as "1" is a valid value the XML document should be validated to ensure that this limit is not violated. This is not an optional piece of validation, it is REQUIRED. ------------------------------------------------------------------------ [2019-11-06 09:45:11] tony at marston-home dot demon dot co dot uk It is clear that you do not understand the structure that I am using. <contacts> is a container that can occur 0 or 1 times. It can contain a number of <contact> elements (arrayOfContactInfo) which themselves are containers for other elements. It is the value of maxOccurs for the <contact> element which is being problematic. Although my data creates 3 occurrences I was testing to see what happens when I set maxOccurs to a smaller value. If I set it to 2 it does not complain that I have exceeded the maxOccurs value. If I set it to 1 it does complain, but the error message is totally wrong. The official specification at http://www.w3.org/TR/xmlschema-0/#OccurrenceConstraints contains the sentence "The maximum number of times an element may appear is determined by the value of a maxOccurs attribute in its declaration." Your code is clearly not validating the maxOccurs value, therefore your code is not following the specification. You say that the data does not *need* to be validated because the developer is supposed to know what they're doing, but you are missing the whole point of WSDL/XSD/DTD validation which verifies that the XML document which it is given conforms to the specified structure in order to trap any mistakes made by the developer. It is supposed to guarantee that the XML document which is received at the other end is exactly as expected. It does this by looking at the minOccurs and maxOccurs value for each element. An element is optional if minOccurs is zero but required if it is greater than zero. The specification also states that no element should occur more times than as stated in the maxOccurs value. Your code is NOT doing this, therefore your code does NOT conform to the specification. ------------------------------------------------------------------------ [2019-11-05 19:45:57] requinix@php.net > It is a container for any number of <contact> elements, Not according to the WSDLs. The one in your report very clearly says maxOccurs=1 and the one in your download says maxOccurs=3. Currently PHP only really cares if maxOccurs>1 or not. If it is then the value being serialized is actually a list (ie, array) of values, who each are to be serialized individually. If you have maxOccurs=1 for an object and pass a list then PHP will complain because the list doesn't have attributes. > The idea that the value of maxOccurs need not be validated is nonsense. In the world of specifications there are two words with two different meanings: "need" and "should". The data does not *need* to be validated because the developer is supposed to know what they're doing, and if they get it wrong then it's not like PHP can automatically recover. The data *should* be validated because that's A Good Thing To Do. PHP does not validate right now. *Should* it? Yes, so the developer can be presented with nicer error messages and, as a more egregious example, not attempt to send invalid data to a service that the client could have known was invalid. But does it *need* to? No, because when used correctly ext/soap is perfectly capable of sending data in its current state. Let me repeat that last sentence to emphasize why I'm making this a doc bug: ext/soap is perfectly capable of sending data in its current state. When you passed a list of objects where the WSDL specified one object, the mistake was on you. PHP could have given you a better error message that more directly indicated the source of the problem, absolutely*, but that doesn't change how PHP was not able to recover and somehow adapt the data to suit. You, the developer, would have to go in and fix your code. Now I really don't want this argument to turn into both of us repeating ourselves until the other person gives up, so here's what you should do: since ext/soap does not currently attempt to validate the data against the WSDL in any way, or even have the functionality to do so AFAIK, you should *request* that validation be *added* so that developers like you and me could make use of it and benefit from the failure messages it may produce. I would suggest that SoapClient gets a "validate" (or perhaps "__validate") method that takes a function name and parameters and validates, and/or that __soapCall() gets an option to opt-into validating before sending. * In case this is a source of confusion, I'm saying PHP could give a better message *in principle*. The cause of your problem is PHP being given a list where it needs an object, but it isn't discovering anything wrong until it reaches the point where it tries to serialize a "first_name" property when it was working on an array with keys (0,1,2). With my quick reading through the source, I don't believe that it *currently* can accurately report some sort of "expecting object, received list" message at that point in the process - all it knows there is that the array doesn't have the required key. ------------------------------------------------------------------------ [2019-11-05 18:45:24] tony at marston-home dot demon dot co dot uk I disagree completely with your assessment. In my WSDL the element <contacts> can occur 0 or 1 times. It is a container for any number of <contact> elements, and each <contact> contains its own group of elements which can occur 0 or 1 times each. The idea that the value of maxOccurs need not be validated is nonsense. The official specification at http://www.w3.org/TR/xmlschema-0/#OccurrenceConstraints contains the sentence "The maximum number of times an element may appear is determined by the value of a maxOccurs attribute in its declaration." To any reasonable person this would mean that if the WSDL provides a value for maxOccurs then the XML document should checked to ensure that this limit is not violated. ------------------------------------------------------------------------ [2019-11-05 17:52:19] requinix@php.net Here's what is happening: If maxOccurs is 1 then the PHP value should not be a list. Because there's only possibly one. It doesn't make sense to have a list when there can only be a single entity/value in it. Like having the title be an array("Title") is weird. If maxOccurs is unbounded or >1, PHP does not validate against the count. It just doesn't. If the max is 2 and you give 3 then it will put in all 3 (which you can verify through __getLastRequest). So there's two issues here: 1. That behavior is undocumented. I think it's the most important aspect of this report, so I'm repurposing this as a doc bug. 2. The missing maxOccurs validation. I don't see this as high priority as it doesn't seem that SoapClient has any particular intention to perform validation beyond what is required to serialize the data to XML; maxOccurs when >1 isn't being validated, minOccurs when >1 isn't being validated, and there are probably other rules not being validated either. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=78749 -- Edit this bug report at https://bugs.php.net/bug.php?id=78749&edit=1