Stan Kitsis : XML Tools

XML Editor in VS2005: Support for inline schemas

skits — Sat, 24 Sep 2005 02:29:00 GMT

The XML Editor provides support for Inline Schemas. Inline schemas are XML schema definitions included inside XML instance documents. They can be used to validate that the rest of the XML matches the schema constraints in the same way that external schema documents can be used. Likewise, the syntax and semantics of inline schemas are the same as for external schemas. Inline schemas can be useful in a number of situations, including:

· An architecture where internal DTDs were used and the developers wish to preserve that design pattern.

· It is difficult to access external files or URLs, e.g. for security or platform reasons.

· There is too much diversity in the set of schemas and instances that a system must process, so it is easiest to simply keep the schema as an integral part of the XML document.

The following XML snippet contains an example of using an inline schema.

<?xml version="1.0" encoding="utf-8"?>

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"

targetNamespace="http://inline"

xmlns="http://inline"

elementFormDefault="qualified"

attributeFormDefault="unqualified">

<xs:element name="parent">

<xs:complexType>

<xs:sequence>

<xs:element name="child" type="xs:string"/>

</xs:sequence>

</xs:complexType>

</xs:element>

</xs:schema>

<inl:parent>

<inl:child>text</inl:child>

</inl:parent>

</root>

You can change the inline schema and the XML Editor will pick up those changes immediately and use the updated schema for validation and intellisense. For example, if you change the <child> element’s type from xs:string to xs:int, you will get a validation error.

XML Editor in VS 2005: Did you know?

skits — Wed, 21 Sep 2005 02:32:00 GMT

Did you know that there are multiple ways of associating a schema with an XML document in the XML Editor? The following list describes all of them in the order in which the XML Editor will look for them

Schemas Property on your XML document
Inline inside your XML document
xsi:schemaLocation or xsi:noNamespaceSchemaLocation attributes in your XML document
Open Document Window.
Anywhere in your current Project
In the Schema Cache Directory or from a Schema Catalog file.

This can be useful if you are working with multiple versions of the same schema. If the XML Editor picks a different schema than the one you want it to use for a particular XML file, then you can always override that choice by editing the Schemas Property on that XML file.

Note that if you rename the schema that your XML document is referencing, then the Schemas Property will be automatically updated to point to the new filename. And if you delete the schema that your XML document is referencing, then the Schemas Property will be cleared and the XML Editor will try to find a new schema using locations and order listed above.

XML Editor in VS2005: Schema Cache and Schema Catalogs

skits — Tue, 20 Sep 2005 04:41:00 GMT

Below are a few tips and tricks on using schema cache and schema catalogs with the new XML Editor in VS 2005.

Schema Cache

The XML Editor comes with a set of schemas that describe some of the W3C standard and some of the VS specific XML namespaces. These schemas are installed into your VS installation directory under %vsinstalldir%\xml\schemas. When you declare one of the namespacess defined by these schemas in your XML files, the XML Editor will automatically associate appropriate schema(s) from the cache location and instantly provide you with intellisense data and validation. The purpose of the schema cache directory is to hold standard schemas as well as schemas that are unlikely to change.

The following operations are supported by the XML Editor without requiring a VS restart.
- Adding schemas
- Deleting schemas
- Renaming schemas

You can also change the schema cache location. This is done by modifying Cache Directory Location on Tools | Options | Text Editor | XML | Miscellaneous dialog. When you do this, the XML Editor will stop using schemas from the old location and instead switch to the new folder.

Schema Catalogs

You can extend existing schema cache using catalog.xml file. VS installs a sample catalog.xml file (along with catalog.xsd) in the schema cache folder. This file can be used to do several things. First of all, you can associate namespaces with external locations as in the following example:

<Schema href="%VsInstallDir%/Common7/IDE/Policy/Schemas/TDLSchema.xsd"

targetNamespace="http://www.microsoft.com/schema/EnterpriseTemplates/TDLSchema"/>

You can also associate file extensions with specific namespaces. The following line taken from the sample catalog.xml associates .config files with dotNetConfig.xsd schema

Finally, you can point your catalog to another catalog file creating a chain:

XML Editor and Code Snippets

skits — Sat, 09 Jul 2005 12:48:00 GMT

Introduction

How many times in your coding life have you had to write or copy-paste code that was almost identical to something that you’d done before? For example, when working on a new xml schema, how many times did you have to write things like

<xs:complexType name="fooType">

<xs:sequence>

<xs:element name="…"/>

…

</xs:sequence>

</xs:complexType>

I know, I know, you can use graphical Schema Editors where you can just point-and-click to generate this code. But can you point-and-click to generate code for a complex type with a sequence of three elements and an xs:any as in the following example?

<xs:complexType name="fooType">

<xs:sequence>

<xs:element name="element1"/>

<xs:element name="element2"/>

<xs:element name="element3"/>

<xs:any namespace="##other" processContents="strict"/>

</xs:sequence>

</xs:complexType>

No? I didn’t think so.

The XML Editor is going to help you with this. VS2005 introduced a new and very powerful feature called Code Snippets. A code snippet is an XML file (with a .snippet extension) that contains a chunk of code in which you can configure different parameters, reference assemblies, and use references and import statements. Think of them as templates that you can configure to meet your needs. The XML Editor supports this feature and also adds dynamically generated code snippets based on your XML Schemas.

Standard (Static) Snippets

Static snippets are available not only in XML Editor, but also in C# and VB. They are created by you or somebody else and stored as .snippet files for future use. When you install XML Editor, you get a number of snippets that we have created for you. For example, a snippet for a new simple type with a pattern restriction:

<xsd:simpleType name="name" xmlns:xsd="http://www.w3.org/2001/XMLSchema">

<xsd:restriction base="xsd:string">

<xsd:pattern value=" "/>

</xsd:restriction>

</xsd:simpleType>

or a C# script block to use in your xslt:

<ms:script implements-prefix="user" xmlns:ms="urn:schemas-microsoft-com:xslt" language="C#" >

double my_code() {

}

</ms:script>

To see a list of all available snippets, go to the Tools menu, select Code Snippets Manager, and then select XML from the dropdown. To insert a snippet, right-click and select “Insert snippet…” (also available from Edit | Intellisense | Insert Snippet or Ctrl+K Ctrl+X). If you are using beta2, you might need to hit SPACE to bring up a list of available snippets. Once you’ve inserted a snippet, you can tab between various modifiable parameters of the snippet, which will be highlighted. The snippet will be “committed” when you hit Enter. Also, note that each snippet can have a shortcut, which you can use to insert it. For example, “stpattern” is a shortcut for the “simple type with a pattern restriction” snippet shown above. To use this shortcut, type “<stpattern” (no closing “>”) and hit TAB. Make sure that before you hit TAB, intellisense drop-down window is not shown (you can hit ESCAPE if it is).

You can also write your own static snippets. All you need to do is to create an xml file in accordance to the schema for snippets, which is installed with VS. There are multiple articles that describe how to create your own snippets for VS. For example, “Code Snippet – Schema Description” by Sean Laberee. However, what these articles fail to mention is that we provide you with a “Snippet for Snippets”. That’s right, all you need to do is create a new XML file, type “<snippet”, hit TAB and fill in the blanks. Now you can create your own libraries of snippets and even share them with your friends and co-workers.

Dynamic Snippets

Dynamic snippets, unlike static snippets, are a unique feature of the XML Editor and are only applicable when working with instance documents that have a schema associated with them. Let’s say you are creating an xml document for a purchase order which contains order ID, customer name, product name, order date, shipping address, and a bunch of other elements. While XML Editor helps you with this by providing intellisense options, it is still a lot of typing. Now in order to provide you with intellisense, the Editor had to parse the schema and at this point knows perfectly well what the structure of the purchase order is. So why not just print it there and let you fill in the values? And that’s exactly what dynamic snippets are. You invoke them in a manner similar to the static snippets – simply type TAB after the element name (for example, “<purchaseOrder”) to get all required attributes and child content pre-populated for you.

Try them out and let me know what you think.