XML-format of assignments for saving data, which can become useful in other programs, sites, and support of songs. It is not easy to create that open file in this format. It is possible to work, navit as it is not installed on the computer, whether there is a special software security.
By itself, XML is the mark of the language, which is similar to HTML, as it is featured on web pages. However, if the remainder is only used for displaying information and correct layout, then XML allows you to structure in a sing-song manner, so that you can build a language similar to an analogue of database data, which does not require a DBMS.
You can create XML files with the help of specialized programs, as well as with a Windows text editor. In view of the PP, the knowledge of the written code and the level of its functionality should be laid down.
Option 1: Visual Studio
The deputy of the editor of the Microsoft code can be selected as an analogue of other retailers. Behind the fact Visual Studio has a larger extended version of the "Notepad". The code can now be specially modified, the pardons are seen or corrected automatically, so the program already has special templates, which allow you to easily create XML files of great volumes.
For the cob work, you need to create a file. Click on item "File" select from the top bar and from the drop-down menu "Create...". Display list, deselect item "File".
The created file will already have the first row with coding and version. For the promotion, the first version and the coding are registered UTF-8, yakі can be changed at any hour. Given to create a full XML file, you need to write all those that were in the previous instructions.
When the work is completed, I will again select from the top panel "File", and there menu menu "Save Everything".
Method 2: Microsoft Excel
You can create an XML file without writing code, for example, with the help of modern versions of Microsoft Excel, which allows you to save tables with extensions. However, it is necessary to be aware of what is possible in this way to create a functional table for a splendid table.
This way is more suitable for those who don't want to or can't work with the code. However, in some way, the koristuvach may run into problems when rewriting the file to the XML format. It's a pity that the operation of transforming a sizable table into XML is possible only on the latest versions of MS Excel. Sob tse robiti, wick the following pokrokov's instruction:
Method 3: Notepad
For robots with XML, you can easily navigate to the original "Notebook" However, if you don’t know the syntax of the movie, it’s important that you need to write different commands and tags in a different way. The process is simpler and much more productive for specialized programs for editing code, for example, for Microsoft Visual Studio. They have special tags and hints, which will make it easier for people to work, badly knowing the syntax of the movie.
For which method it is not necessary to zavantazhuvat, to that in the operating system already vbudovaniya "Notebook". Let's try to break into a new simple XML table for this instruction:
Approximately so you can look at the finished result:
XML compilers are responsible for parsing this code in a table with one column, showing data about Ivan Ivanov.
At "Notebooks" as a whole it is possible to create clumsy tables for zrazok tsієї, but when collapsing larger volumes of data, they can create folding, so like a great "Notebooks" there are no functions to correct the pardons of the code, or any of them.
As you can see, there is nothing coherent in the created XML file. For the sake of yoga, you can create something like a koristuvach, like a bigger-lesser you can practice on a computer. However, in order to create a complete XML file, it is recommended to use the same layout, even if it is on a primitive level.
For all applications below, the XSL movie standard has been changed. Widely zastosovuєtsya also modern modification of this standard - mov XSL T, You can read more about it in \xml\XSLTutorial or MSDN.
Let's look at a simple example of an XML file (ex01.xml). These and other examples can be found in the folder \xml\XSLTForBeginers on disk.
If we view this file in the Internet Explorer browser, then we can use the same text, which is shown above, together with the same tags and service information. Ale, we don’t need tags and service information! We want to bachit only that information, as it is necessary to do it right, and for additional tags - look at the information with a stern look. It is easy and simple to change the task: it is necessary to add a transformation template to the XML file - an XSL file.
Let's rewrite our XML file to look like this (ex01-1.xml).
І create XSL file ex01-1.xsl. The text of the file is hovered below.
Since we now view the ex01-1.xsl file in the Internet Explorer browser, then we are sorry that our task has been completed, - the necessary information was left on the screen, all the tags appeared. The result you see on the browser screen is hovered below.
"Notes about XSL"
It is also easy to think that the order in which rows are displayed in our country depends on a simpler template of transformation - the XSL file. If necessary, the template can be easily changed without changing our main XML file at all.
Let's rewrite the XML file. The informational part will not be changed, but the template may be ex01-2.xml.
Let's create the XSL ex01-2.xsl file. The text of the file is hovered below.
If I view the ex01-2.xsl file in Internet Explorer, the result will be different.
"Notes about XSL"
It is significant now that this is the key moment for retailers of databases. Information from the XML-side is, as a rule, as a result of a request to the data base. Washing up to the base of data from the bankrupt on a rich coristuvachіv seredovishchi - the operation is more expensive. It is acceptable now that we don't have XML and we form standard static HTML sides. For example, for changing the sorting, we have two ways to solve the problem: to solve the problem: to vikonate and save the results in the same time buffer on the server, or else, when changing the call of the previous event side anew.
The first way to make laborious programming, the other way to significantly increase the load on the data base server, the productivity of which is often the bottleneck of the system, is to make sure you want to take better results.
XML and XSL are the final solution to the described problem. In fact, the XML-side is a time buffer for the results of requests. Only the replacement of non-standard and labor-intensive programming by victorious standard XSL mechanism.
One more mirkuvannya, yak can be a source for retailers of databases. Most of today's DBMSs can format the results of a query to a data base in a look-alike XML file. That is why, with the help of the interface of the correspondent within the framework of the technology XML and XSL, we can reach the same independence from the postal manager of the DBMS. Part of the organization has seen practically all the independence. And this part is even greater in most applied systems, oriented to practice with data bases. Obviously, the crimson is also the introduction of that server-side processing of business logic, but here you happen to have some other solutions.
First steps
Let's take a closer look at the first butt now. Let's guess, yogo text.
The first row informs the browser that the file is in XML format. The version attribute is language specific. The encoding attribute is not necessarily language-specific, but if you have Russian letters in your text, then you need to insert the attribute, otherwise the XML file simply won't be processed, - you won't be told about the pardon.
Next rows - whole XML file. It is made up of elements, which have a tree-like structure in the totality. Elements are identified by tags and can be nested one into one.
Elements can contain attributes, the values of which can be converted to a template.
The top level of the XML file must always have one element. Tobto mind file
not processed by the browser. To convert to a correct XML file, you need to add the tags of the top level element, for example
Significantly, tag names are case-sensitive. Reports about it can be read in any book on XML - elements and attributes in these books should be given great respect.
Now let's move on to the transformation template - to the XSL file. XSL file task - convert the tree to the XML file into another tree, for example, it will match the HTML format and can be displayed on the browser screen with improved formatting, font selection even more.
In order for the Vicon browser to be redesigned, it is necessary to indicate in the XML file the message for the XSL file
Now let's look at the text in the XSL file
The first row in the file is the xsl element tag: stylesheet. The attribute of the element is the version number that was sent to the space of names. The attributes of the xsl:stylesheet element are language specific. Our view has a wide range of names - all the names of the elements and their attributes, which can be typed in the XSL file. For XSL files, use the standard filename space.
Respectfully, the XSL file is one of the different XML files. Vіn do not avenge the data, but the yoga format is the same. The file contains the element of the top level xsl:stylesheet, and then the tree of rules of transformation is given.
For this document, we will not explicitly explain what a skin element means to an XSL file. We will make a difference application and show the result in a skin application, which will allow you to independently set the difference elements of the XSL file and the elements of the transformation of the XML file with the information of the koristuvach. Consider also the meaning of the attribute select and similar ones with a zmist "select" are recorded in a special mine XPath, about which you can read briefly on the \xml\XPathTutorial disk, and more on MSDN.
Nadalі texts of XML- and XSL-files we will point at the black-and-white version. You can always open the real file and see all the colors. If necessary, comment out the message to the XSL file. Advance comment syntax. Symbols cannot be inserted in the comment text.
In the first example, we were surprised, as behind the help of the xsl: value-of element, you can enter the HTML format of the element (text, arrangements between tags). Now let's wonder how, behind the help of that very element, you can enter the value of the attribute of the element.
Let's take a look at the next XML file ex02-1.xml
In the previous article about XML, we looked at such an old way of validating XML documents, like XML DTD. Tsej sposіb dosі zastosovuєtsya for reverification of XML-data, but with the skin day yogo more and more vitiсnіє new technology called XML Schema. In XML schemas, some minor flaws have been corrected, as if they were in XML DTD, so at the moment, all leading retailers for document validation only require XML schemas.
To evaluate the superiority of XML Schemas (XML Schema) over DTDs, let's take a closer look at the main shortcomings of DTDs that have been successfully corrected in XML Schemas. I’ve already guessed about them at the article “B”, but for the sake of brevity, let’s repeat.
Shortcomings of XML DTD over XML Schema
- View XML syntax movie. So DTD is not XML. Communication with CIM may cause various problems with coding and verification of XML documents.
- There is no re-verification of data types. XML DTD has only one type of data - a row. For example, if there is text in the numeric field, the document will still pass verification, XML DTD shards cannot override the data type.
- It is not possible to set more than one DTD description for up to one XML document. To verify a document, you can use only one DTD description. As if it were a sprat, it would be possible to rewrite the inventory and put it all in one file, which is already clumsy.
These were the main shortcomings of the XML DTD, which were successfully corrected in the industry standard description of XML documents XML Schema.
XML Schema - a promissory standard for describing XML documents
As short as it is, the XML Schema can be done like this:
- Describe the names of elements and attributes (dictionary).
- Describe the relationship between elements and attributes, as well as their structure (the model is correct).
- Viznaє types of data.
I also want to respect that for a given moment, for the help of schemes, practically everything can be described. Therefore, a schema is a universal way to describe the grammar of data, which can be used for verification of XML documents, and also a description of databases. In this rank, the scope of stosuvannya schemes at the given moment is much wider.
XML Schema application for XML document validation
As practice shows, the material will be more easily conquered, as soon as a start is made with applications. I’ll tell you once again that we won’t be able to get lost in everything thin, for that the material is even more foldable, especially like it’s twisted in the text.
An example of a simple XML schema
For the help of the schema, you can rewrite the XML document of such a change.
<книга xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation = "book.xsd"> <название>Fundamentals of XML <цена>300
Now, let's turn to our XML schema. As you already mentioned, for the creation of XML schemas, we already know XML. The only difference here is that the XML Schema has already assigned elements, on top of the original XML. At the link with z tsim vikoristovuyutsya expanse of names. In this case, the common name will be "http://www.w3.org/2001/XMLSchema", which should be asked for the additional "xs" prefix.
I want to respect that you can win as a prefix of the space of names, so you can set the space of the names of the root element. There is no such difference here. Kozhen himself virishu, how to fix it in this situation. I will only say that the prefixes xs or xsd are ringing.
Well, now let's figure it out, how to decipher it I'll bring up a larger scheme. As mentioned above, XML Schema describes vocabulary and data types. Vіdshtovhuyuchis vіd tsgogo, zrobimo deciphering the skin element.
Like bachite, there is nothing superfluous here. If you think about it, then everything is even simpler.
Main elements of XML Schema
In short, the XML Schema can be described as follows.
As you can see from the butt, an XML skin schema is made up of a root element "schema" and a bounding naming space "http://www.w3.org/2001/XMLSchema". Give a description of the scheme and the scheme itself. For some reason, often in the arc of the same schemas, the description is significantly larger, lower than the XML Schema itself.
Description of elements in XML Schema
On the cob of the article, we have already looked at the example of the simplest XML schema. They described the elements of tipi in detail. In any case, I want to respect that the consequence here cannot be significant. Scheme of pracyuvatime at any time.
Now let's look at another way to write XML Schema that focuses on describing the type right away in the middle of an element. Tsey way to come up in that moment, as you do not plan to win the same description for different elements. For clarity, let's look at the butt.
As can be seen from the butt, the element is voiced for the help of a special construction element with a different type of prefix. In this case, we will define the element with the name "root" without specifying the type (type), the shards of the wines will be descriptions of the middle element. There are two ways to describe the elements.
1 way
2 way
You can win as the first way, as well as the other. Usі stink pratsyyut however. Nutrition is less for clarity in this particular mood.
Dali after the omission of the element, we indicate that the wine is of a complex type (
Yak bachite, as long as everything is easy to finish. Well, I know, we won’t go into all the details, the fragments of this article are recognized for familiarization with XML Schema, and not for detailed readings.
How to set XML Schema visibility for that document
Especially XML Schema and those that describe not the document itself, but the scope of names. In connection with this, most of the everyday riddles about her are not found in the documents. Obroblyuvach himself to put in vіdpovіdnіst vіdpovіdnіst іnіt'll need іn уоur schema without whistle-blowing any instructions in the XML-document.
On the verge, as if you don’t know the master, where to lay the scheme, we can say, de її shukati. Try to help the special "schemaLocation" attribute. Oskіlki tsey attribute to belong to the other expanse of names, before the cob of vikoristannya attribute of expanse it is necessary to indicate. For clarity, let's look at the butt.
XML Schema
XML document
Now let's report on a row of leather. On whom everything. Good luck and good luck with XML! Someone else will show you how to write XML schemas. You also know that circuits can be written in different ways. Let's look at the next XML document called "shiporder.xml":
Hover over an XML document is composed of a root element ship order with a language attribute orderid
. element ship order avenge three child elements: orderperson, ship toі item. element item vikoristovuєtsya dvіchi and vengeance element title, neob'viscous element note, as well as elements quantityі price. Row xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
Tell the XML parser that the document can be re-validated to the schema. Row xsi:noNamespaceSchemaLocation="shiporder.xsd"
Please, de itself know the scheme (which one has to know in the same folder as the file "shiporder.xml"). Now let's create an XML Schema for the overridden XML document. Let's create a new file, which is called shiporder.xsd. To create an XML schema, simply follow the structure of the XML document and define the skin element. Let's look at the standard XML declaration for which we describe the element xs:schema
, which signifies the scheme itself:
Here mi vikoristovuemo standard space of names ( xs
) that URI associated with this space of names, which may be the standard value http://www.w3.org/2001/XMLSchema
. Now we can assign the element ship order. This element can be an attribute, and you can find other elements, so we consider it as an element of a folded type. Designation of daughter elements ship order let's wait until the declaration xs:sequence
what sets the sequence of sub-elements:
Now significant element orderperson, which will be of a simple type (the shards of wine do not avenge neither attributes nor other elements). Yogo type ( xs:string
) may prefix the space of names associated with the XML schema, which indicates the variation of the data type:
Now we need to assign: ship toі item. Let's fix the designation of the element ship to:
For the help of schemes, we can designate any element. Whom will help us attributes maxOccurs
і minOccurs
. Attribute maxOccurs
sets the maximum number of entry of the element, and the attribute minOccurs
set the minimum number of entries. For abbreviations, the meaning of both attributes is beautiful 1. Now significant element item. This element can be victorious without limiting the number of times in the middle of the element ship order. Designate such a feature of the element item allow attribute attachment maxOccurs
meaning "unbounded"
. Tse means that the element item you can win the stylki razіv, skіlki it is necessary for the author of the document. Give respect, what an element note optional. By meaningfully setting the attribute minOccurs
at zero value:
We can now declare an element attribute ship order. Oskіlki tse obov'yazykovy attribute, vikoristovuєmo vyznachennya use="required"
. Note: Attributes must always be declared by the rest:
Axis code for the schema file "shiporder.xsd":
The forward method of arranging the scheme is even simpler, if the document is folded, with a similar method, the layout of the schemes can be cumbersome, which will appear on the clarity of reading and serving. The next method of arranging the scheme is based on the fact that all the elements of the attribute are assigned first, and then the assignment is made for the help of the attribute ref
. Below is a new layout for the schema file ("shiporder.xsd"):
The third way of arranging the scheme for transferring the designation of classes and types, which allows you to re-designate the designation of elements. We can only give names to elements simpleTypes
і complexTypes
, and then tell them for a help attribute type
. Third way to link the schema file ("shiporder.xsd"):
element restriction Indicates that the data type is similar to the data types in the W3C XML Schema naming space. In this way, the next fragment of the code means that the value of an element or an attribute can be in a row:
However, more often than not, the element restriction vikoristovuєtsya for laying the border on the elements. Look at the next rows from the above diagram:
This fragment of the code points to those that the value of the element or the attribute can be row, equal to six characters at the bottom, and with the same characters as digits from 0 to 9.XML document
Creating an XML Schema
Podil schemes
Selection of borrowed types