Try this

    &lt;xs:element name=&quot;description&quot; type=&quot;xs:string&quot; minOccurs=&quot;0&quot; maxOccurs=&quot;1&quot; /&gt;

if you want 0 or 1 &quot;description&quot; elements, Or

    &lt;xs:element name=&quot;description&quot; type=&quot;xs:string&quot; minOccurs=&quot;0&quot; maxOccurs=&quot;unbounded&quot; /&gt;

if you want 0 to infinity number of &quot;description&quot; elements.

Set the `minOccurs` attribute to `0` in the schema like so:

    &lt;?xml version=&quot;1.0&quot;?&gt;
      &lt;xs:schema version=&quot;1.0&quot; xmlns:xs=&quot;http://www.w3.org/2001/XMLSchema&quot; elementFormDefault=&quot;qualified&quot;&gt;
        &lt;xs:element name=&quot;request&quot;&gt;
            &lt;xs:complexType&gt;
                &lt;xs:sequence&gt;
                    &lt;xs:element name=&quot;amenity&quot;&gt;
                        &lt;xs:complexType&gt;
                            &lt;xs:sequence&gt;
                                &lt;xs:element name=&quot;description&quot; type=&quot;xs:string&quot; minOccurs=&quot;0&quot; /&gt;
                            &lt;/xs:sequence&gt;
                        &lt;/xs:complexType&gt;
                    &lt;/xs:element&gt;
                &lt;/xs:sequence&gt;
            &lt;/xs:complexType&gt;
        &lt;/xs:element&gt; &lt;/xs:schema&gt;



I have three functions that find the nth element of a list:

    nthElement :: [a] -&gt; Int -&gt; Maybe a 
    nthElement [] a = Nothing
    nthElement (x:xs) a | a &lt;= 0 = Nothing
                        | a == 1 = Just x
                        | a &gt; 1 = nthElement xs (a-1)

    nthElementIf :: [a] -&gt; Int -&gt; Maybe a
    nthElementIf [] a = Nothing
    nthElementIf (x:xs) a = if a &lt;= 1
                            then if a &lt;= 0 
                                 then Nothing
                                 else Just x -- a == 1
                            else nthElementIf xs (a-1)                           

    nthElementCases :: [a] -&gt; Int -&gt; Maybe a
    nthElementCases [] a = Nothing
    nthElementCases (x:xs) a = case a &lt;= 0 of
                                 True -&gt; Nothing
                                 False -&gt; case a == 1 of
                                            True -&gt; Just x
                                            False -&gt; nthElementCases xs (a-1)

In my opinion, the first function is the best implementation because it is the most concise. But is there anything about the other two implementations that would make them preferable? And by extension, how would you choose between using guards, if-then-else statements, and cases?

Guards vs. if-then-else vs. cases in Haskell

I&#39;ve realized that Chrome, it seems, will not allow me to hide `&lt;option&gt;` in a `&lt;select&gt;`. Firefox will.

I need to hide the `&lt;option&gt;`s that match a search criteria. In the Chrome web tools I can see that they are correctly being set to `display: none;` by my JavaScript, but once then `&lt;select&gt;` menu is clicked they are shown.

How can I make these `&lt;option&gt;`s that match my search criteria NOT show when the menu is clicked? Thanks!

How to hide a &lt;option&gt; in a &lt;select&gt; menu with CSS?

So I got this XML schema:

    &lt;?xml version=&quot;1.0&quot;?&gt; &lt;xs:schema version=&quot;1.0&quot;
               xmlns:xs=&quot;http://www.w3.org/2001/XMLSchema&quot;
               elementFormDefault=&quot;qualified&quot;&gt;
        &lt;xs:element name=&quot;request&quot;&gt;
            &lt;xs:complexType&gt;
                &lt;xs:sequence&gt;
                    &lt;xs:element name=&quot;amenity&quot;&gt;
                        &lt;xs:complexType&gt;
                            &lt;xs:sequence&gt;
                                &lt;xs:element name=&quot;description&quot; type=&quot;xs:string&quot; /&gt;
                            &lt;/xs:sequence&gt;
                        &lt;/xs:complexType&gt;
                    &lt;/xs:element&gt;
                &lt;/xs:sequence&gt;
            &lt;/xs:complexType&gt;
        &lt;/xs:element&gt; &lt;/xs:schema&gt;

How do I make the description element optional? So both XML with the description element and without will validate against the XSD.

How to make an element in XML schema optional?

So I got this XML schema:
<pre><code class="hljs language-xml">&#x3C;?xml version="1.0"?> &#x3C;xs:schema version="1.0"
 xmlns:xs="http://www.w3.org/2001/XMLSchema"
 elementFormDefault="qualified">
 &#x3C;xs:element name="request">
 &#x3C;xs:complexType>
 &#x3C;xs:sequence>
 &#x3C;xs:element name="amenity">
 &#x3C;xs:complexType>
 &#x3C;xs:sequence>
 &#x3C;xs:element name="description" type="xs:string" />
 &#x3C;/xs:sequence>
 &#x3C;/xs:complexType>
 &#x3C;/xs:element>
 &#x3C;/xs:sequence>
 &#x3C;/xs:complexType>
 &#x3C;/xs:element> &#x3C;/xs:schema>
</code></pre>
How do I make the description element optional? So both XML with the description element and without will validate against the XSD.

I am getting an error when trying to set my view to display the `ListView` for the file I want to display(text file). I am pretty sure it has something to do with the XML. I just want to display the information from `this.file = fileop.ReadFileAsList(&quot;Installed_packages.txt&quot;);`. My code:

    public class Main extends Activity {
    	private TextView tv;
    	private FileOperations fileop;
    	private String[] file;
    
    	/** Called when the activity is first created. */    	
    	@Override
    	public void onCreate(Bundle savedInstanceState) {    		
    		super.onCreate(savedInstanceState); 
    		this.fileop = new FileOperations(); 
    		this.file = fileop.ReadFileAsList(&quot;Installed_packages.txt&quot;); 
    		setContentView(R.layout.main);
    		tv = (TextView) findViewById(R.id.TextView01);
    		ListView lv = new ListView(this);
    		lv.setTextFilterEnabled(true); 
    		lv.setAdapter(new ArrayAdapter&lt;String&gt;(this, R.layout.list_item, this.file)); 
    		lv.setOnItemClickListener(new AdapterView.OnItemClickListener() { 

    		      public void onItemClick(AdapterView&lt;?&gt; parent, View view, 	int position, long id) { 
                 		// When clicked, show a toast with the TextView text 
                		Toast.makeText(getApplicationContext(), ((TextView) view).getText(), Toast.LENGTH_SHORT).show(); 
    		      } 
    		});    		
    		setContentView(lv);
    	}
    	
    }


**list_item.xml** :
    
    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;LinearLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        android:layout_width=&quot;fill_parent&quot;
        android:layout_height=&quot;fill_parent&quot;
        android:orientation=&quot;vertical&quot; 
        android:padding=&quot;10dp&quot;   
        android:textSize=&quot;16sp&quot;   
        android:textColor=&quot;#000&quot;&gt;
    
    &lt;/LinearLayout&gt;



**main.xml** :
    
    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;LinearLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        android:orientation=&quot;vertical&quot;
        android:layout_width=&quot;fill_parent&quot;
        android:layout_height=&quot;fill_parent&quot;
        android:weightSum=&quot;1&quot;&gt;
    &lt;ScrollView
        android:id=&quot;@+id/SCROLLER_ID&quot;
        android:layout_width=&quot;fill_parent&quot;
        android:layout_height=&quot;wrap_content&quot;
        android:scrollbars=&quot;vertical&quot;
        android:fillViewport=&quot;true&quot;&gt;
    		&lt;TextView  
       	 	android:layout_width=&quot;fill_parent&quot; 
       	 	android:layout_height=&quot;wrap_content&quot; 
       		android:padding=&quot;5sp&quot;
        	android:id=&quot;@+id/TextView01&quot;
        	android:text=&quot;@string/hello&quot;/&gt;
    	&lt;/ScrollView&gt;
        
    &lt;/LinearLayout&gt;



&quot;ArrayAdapter requires the resource ID to be a TextView&quot; XML problems

I have added a custom font file to my assets/fonts folder. How do I use it from my XML? 

I can use it from code as follows:

&lt;!- language: java --&gt;


    TextView text = (TextView) findViewById(R.id.textview03);
    Typeface tf = Typeface.createFromAsset(getAssets(), &quot;fonts/Molot.otf&quot;);
    text.setTypeface(tf);

Can&#39;t I do it from XML using an `android:typeface=&quot;/fonts/Molot.otf&quot;` attribute?

Using custom font in android TextView using xml

I&#39;m developing a language dictionary app. I save the favourite word into Preference. The Favourite content in the XML file looks like the following:

&lt;!-- language: lang-xml --&gt;

    &lt;?xml version=&#39;1.0&#39; encoding=&#39;utf-8&#39; standalone=&#39;yes&#39; ?&gt;
      &lt;map&gt;
        &lt;string name=&quot;history&quot;&gt;
          dict_name::160170::hi,dict_name::157140::he-man,dict_name::184774::jet,dict_name::34527::black
        &lt;/string&gt;
        &lt;string name=&quot;waitingTime&quot;&gt;
          0
        &lt;/string&gt;
        &lt;boolean name=&quot;saveFavourite&quot; value=&quot;true&quot; /&gt;
        &lt;string name=&quot;defaultDictionary&quot;&gt;
          dict_name
        &lt;/string&gt;
        &lt;string name=&quot;favourite&quot;&gt;
          dict_name::149271::go,dict_name::25481::back,dict_name::184774::jet
        &lt;/string&gt;
        &lt;boolean name=&quot;saveHistory&quot; value=&quot;true&quot; /&gt;
      &lt;/map&gt;

I use the following code to load the Favourite content into the webview:

&lt;!-- language: lang-java --&gt;

    public class User extends Activity {
    	private static final String FAVOURITE_TAG = &quot;[MyDict - FavouriteView] &quot;;
    	private static final String CONTENT_TAG = null;
    
    	private ListView mLSTFavourite = null;
    	private ArrayList&lt;String&gt; lstDict = null;
    	private ArrayList&lt;Integer&gt; lstId = null;
    	private ArrayList&lt;String&gt; mWordFavourite = null;
    	private ArrayAdapter&lt;String&gt; aptList = null;
    	private SharedPreferences prefs;
    
    	@Override
    	public void onCreate(Bundle savedInstanceState) {
    		super.onCreate(savedInstanceState);
    		setContentView(R.layout.favourite);
    		prefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
    
    		if (prefs.getBoolean(&quot;saveFavourite&quot;, true)) {
    			String strFavourite = prefs.getString(&quot;favourite&quot;, &quot;&quot;);
    			Log.i(FAVOURITE_TAG, &quot;Favourite loaded&quot;);
    			if (strFavourite != null &amp;&amp; !strFavourite.equals(&quot;&quot;)) {
    				mWordFavourite = new ArrayList&lt;String&gt;(Arrays.asList(strFavourite.split(&quot;,&quot;)));
    			} else {
    				mWordFavourite = new ArrayList&lt;String&gt;();
    			}
    		} else {
    			mWordFavourite = new ArrayList&lt;String&gt;();
    		}
    
    		Log.d(FAVOURITE_TAG, &quot;mWordFavourite = &quot; + mWordFavourite.size());
    		mLSTFavourite = (ListView) findViewById(R.id.lstFavourite);
    
    		ImageButton btnClear = (ImageButton) findViewById(R.id.btnClear);
    		ImageButton btnBackToContent = (ImageButton) findViewById(R.id.btnBackToContent);
    
    		if (lstDict == null) {
    			lstDict = new ArrayList&lt;String&gt;();
    			lstId = new ArrayList&lt;Integer&gt;();
    			aptList = new ArrayAdapter&lt;String&gt;(getApplicationContext(), R.layout.customlist);
    		}
    		lstDict.clear();
    		lstId.clear();
    		aptList.clear();
    		
    		if (mWordFavourite != null &amp;&amp; mWordFavourite.size() &gt; 0) {
    			try {
    				for (int i = 0; i &lt; mWordFavourite.size(); i++) {
    					Log.i(FAVOURITE_TAG, &quot;item = &quot; + mWordFavourite.get(i));
    					String arrPart[] = mWordFavourite.get(i).split(&quot;::&quot;);
    					if (arrPart.length == 3) {
    						Log.i(CONTENT_TAG, &quot;loaded content &quot; + arrPart.length + &quot;, wordId = &quot; + arrPart[1]);
    						// Log.i(CONTENT_TAG, &quot;loaded 0&quot;);
    						lstDict.add(i, arrPart[0]);
    						// Log.i(CONTENT_TAG, &quot;loaded 1&quot;);
    						lstId.add(i, Integer.parseInt(arrPart[1]));
    						// Log.i(CONTENT_TAG, &quot;loaded 2&quot;);
    						aptList.add(arrPart[2]);
    					} else {
    						Log.i(FAVOURITE_TAG, &quot;Wrong entry: &quot; + mWordFavourite.get(i));
    					}
    				}
    			} catch (Exception ex) {
    				Log.i(FAVOURITE_TAG, &quot;Wrong entry found!&quot;);
    			}
    		}
    		// Log.i(CONTENT_TAG,&quot;Adapter size = &quot; + aptList.getCount());
    		// assign result return
    		mLSTFavourite.setAdapter(aptList);
    		mLSTFavourite.setOnItemClickListener(new AdapterView.OnItemClickListener() {
    					public void onItemClick(AdapterView&lt;?&gt; arg0, View v, int arg2, long arg3) {
    						// mEDWord.setText(mAdapter.getItem(arg2));
    						Intent i = new Intent();
    						i.putExtra(&quot;dict&quot;, lstDict.get(arg2));
    						i.putExtra(&quot;wordId&quot;, lstId.get(arg2));
    						setResult(RESULT_OK, i);
    						finish();
    					}
    				});
    		btnClear.setOnClickListener(new View.OnClickListener() {
    			@Override
    			public void onClick(View v) {
    				// TODO Auto-generated method stub
    				mWordFavourite.clear();
    				aptList.clear();
    				mLSTFavourite.setAdapter(aptList);
    				SharedPreferences.Editor editor = prefs.edit();
    				editor.putString(&quot;favourite&quot;, &quot;&quot;);
    				editor.commit();
    				setResult(RESULT_OK);
    				finish();
    			}
    		});
    
    		btnBackToContent.setOnClickListener(new View.OnClickListener() {
    			@Override
    			public void onClick(View v) {
    				setResult(RESULT_CANCELED);
    				finish();
    			}
    		});
    	}
    }

The Favourite content is successfully loaded. The favourite words are listed in the webview. But the problem is that it only shows the definition of the latest word added to the Favourite regardless of what word is chosen. For example:

    word1
    word2
    word3

Despite word1 and/or word2 is selected for meaning, the definition of the last word, which is word3, is always shown. My purpose is to display the definition of `word1` when `word1` is selected, and the definition of `word2` when `word2` is selected, and so on and so forth. I save my dictionary data in SQLite database.

Can anybody there help to solve this problem.

Favourite content is not shown correctly on webview

This is when using XDocument from .net.

I thought this might work...

    xElement.Element(elementName).Value = new XCData(value).ToString();

... but it comes out like this...

    &lt;name&gt;&amp;lt;![CDATA[hello world]]&amp;gt;&lt;/name&gt;

How do I make the value of an XElement be wrapped in ![CDATA[***]]?

I have a vertical LinearLayout containing an ImageView and a few other layouts and views.

    &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
    &lt;LinearLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        android:orientation=&quot;vertical&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;&gt;
        
        &lt;ImageView
            android:layout_width=&quot;match_parent&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:contentDescription=&quot;@string/banner_alt&quot;
            android:src=&quot;@drawable/banner_portrait&quot; /&gt;
          
        &lt;TextView
          android:layout_width=&quot;match_parent&quot;
          android:layout_height=&quot;wrap_content&quot;
          android:text=&quot;@string/main_search&quot;
          android:gravity=&quot;center&quot;
          android:textStyle=&quot;bold&quot; /&gt;
          
        &lt;LinearLayout
          android:orientation=&quot;horizontal&quot;
          android:layout_width=&quot;match_parent&quot;
          android:layout_height=&quot;wrap_content&quot; &gt;
        
          &lt;Spinner
            android:id=&quot;@+id/search_city_spinner&quot;
            android:layout_width=&quot;0px&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:layout_weight=&quot;1&quot;
            android:prompt=&quot;@string/search_city_prompt&quot;
            android:entries=&quot;@array/search_city_array&quot; /&gt;
        
          &lt;Spinner
            android:id=&quot;@+id/search_area_spinner&quot;
            android:layout_width=&quot;0px&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:layout_weight=&quot;1&quot;
            android:prompt=&quot;@string/search_area_prompt&quot;
            android:entries=&quot;@array/search_area_array&quot; /&gt;
          
        &lt;/LinearLayout&gt;
          
        &lt;LinearLayout
          android:orientation=&quot;horizontal&quot;
          android:layout_width=&quot;match_parent&quot;
          android:layout_height=&quot;wrap_content&quot; &gt;
        
          &lt;Spinner
            android:id=&quot;@+id/search_rooms_spinner&quot;
            android:layout_width=&quot;0px&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:layout_weight=&quot;1&quot;
            android:prompt=&quot;@string/search_rooms_prompt&quot;
            android:entries=&quot;@array/search_rooms_array&quot; /&gt;
        
          &lt;Spinner
            android:id=&quot;@+id/search_min_spinner&quot;
            android:layout_width=&quot;0px&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:layout_weight=&quot;1&quot;
            android:prompt=&quot;@string/search_min_prompt&quot;
            android:entries=&quot;@array/search_min_array&quot; /&gt;
        
          &lt;Spinner
            android:id=&quot;@+id/search_max_spinner&quot;
            android:layout_width=&quot;0px&quot;
            android:layout_height=&quot;wrap_content&quot;
            android:layout_weight=&quot;1&quot;
            android:prompt=&quot;@string/search_max_prompt&quot;
            android:entries=&quot;@array/search_max_array&quot; /&gt;
          
        &lt;/LinearLayout&gt;
        
        &lt;Button
          android:id=&quot;@+id/saearch_button&quot;
          android:layout_width=&quot;match_parent&quot;
          android:layout_height=&quot;wrap_content&quot;
          android:text=&quot;@string/search_button&quot;
          android:onClick=&quot;searchButton&quot; /&gt;
        
    &lt;/LinearLayout&gt;

My problem is that when the activity is displayed, the ImageView has a padding at the top &amp; bottom. I&#39;ve confirmed it is the ImageView (by setting a background colour on the ImageView).

The image is 450x450px. Setting the height manually to 450px produces the desired effect (no padding), and setting it to 450dp produces the same effect as using wrap_content.

It seems that android is taking the height of the image (450px) and setting the height of the ImageView to the same value, but in dp.

Any ideas as to what I can do to fix this? I don&#39;t want to use absolute values as I&#39;ll be providing different images for different screen densities.

ImageView in android XML layout with layout_height=&quot;wrap_content&quot; has padding top &amp; bottom

I would like to understand the purpose of targetNamespace as used both in XML Schema and in WSDL. In fact, to keep things simple, let&#39;s limit this question to XML Schema.

I feel like I fully understand the notion of (simple) XML namespaces. By convention we use URI/URLs, but we could use any string, which we then assign to a prefix for reuse by XML nodes and attributes, or use simply as the default namespace for the scope at hand. So far, so good ?

Now enters XML Schema. For some reason the inventors of XML Schema felt the notion of simple namespaces wasn&#39;t enough and they had to introduce the targetNamespace. My question is : what significant benefit does a targetNamespace introduce that couldn&#39;t be provided by a normal XML namespace ? If an XML document references a xsd document, either by schemaLocation or with an import statement, in either case I give the path to the actual xsd document being referenced. This is what uniquely defines the Schema I want to refer to. If in addition I want to bind this Schema to a particular namespace in my referencing document, why should I be obliged to replicate the precise targetNamespace already defined in the XML Schema I am referencing? Why couldn&#39;t I simply redefine this namespace however I want within the XML document in which this namespace will be used to refer to that particular XML Schema document I want to reference ?

Update:

To give an example, if I have the following in an XML instance document:

    &lt;p:Person
       xmlns:p=&quot;http://contoso.com/People&quot;
       xmlns:v=&quot;http://contoso.com/Vehicles&quot;
       xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
       xsi:schemaLocation=
        &quot;http://contoso.com/schemas/Vehicles
         http://contoso.com/schemas/vehicles.xsd
         http://contoso.com/schemas/People
         http://contoso.com/schemas/people.xsd&quot;&gt;
       &lt;name&gt;John&lt;/name&gt;
       &lt;age&gt;28&lt;/age&gt;
       &lt;height&gt;59&lt;/height&gt;
       &lt;v:Vehicle&gt;
          &lt;color&gt;Red&lt;/color&gt;
          &lt;wheels&gt;4&lt;/wheels&gt;
          &lt;seats&gt;2&lt;/seats&gt;
       &lt;/v:Vehicle&gt;
    &lt;/p:Person&gt;

Why does e.g. the people.xsd Schema need to define a targetNamespace which is &quot;http://contoso.com/schemas/People&quot;? Why do we need the targetNamespace definition in the xsd document at all? It seems to me all you have to gain from the namespace part of the schemaLocation is already contained in the XML instance document. What is the benefit of enforcing the existence of a targetNamespace with equal value over in the xsd document ?

Follow-up question to Paul&#39;s answer:

Can you give me a concrete example where such &quot;clashes&quot; between xsd element names becomes apparent and that would explain the need for targetNamespace ?

-----------

Ok, here&#39;s an attempt to answer my own question. Let me know if it seems coherent to you. Looking at the examples on the page linked by Paul helped me.

If we take the XML instance example in the original question above, we have two references to the definition of the vehicle element. One is explicit and visible in the XML instance document itself, but we must also imagine that the person.xsd XML Schema references the same vehicle definition again as an allowed child element of person. If we were to use normal namespaces where each document were allowed to define its own namespace for vehicle, how would we know that the XML instance is referencing the same XML Schema definition for vehicle as is the person.xsd ? The only way is by enforcing a concept of namespace which is stricter than the original simple one and which must be written exactly the same way across multiple documents.

If I wasn&#39;t writing this on a tablet I would provide a code example, but here I will just attempt to describe the example I have in mind.

Imagine that we have two different XML Schema definitions for a vehicle element. location1/vehicles.xsd would contain the definition that validates the example from the question of this post (containing color, wheels, and seats child elements), whereas location2/vehicles.xsd would contain an entirely different definition for a vehicle element, (say, with child elements year, model, and volume). Now, if the XML instance document refers to the location1 Schema, as is the case in the example above, but person.xsd says that the person element can contain a vehicle child element of the type defined in the location2 Schema, then without the notion of a targetNamespace, the XML instance would validate, even though it clearly doesn&#39;t have the right kind of vehicle as a child element of its person element.

Target namespaces then help us make sure that if two different documents are referencing the same third XML Schema, that they are both in deed referencing the same Schema and not just a Schema that contains elements that are similar, but not identical to one another...

Does that make any sense ?

Why do we need targetNamespace?

I want to know the correct syntax for defining an element containing both attributes and child elements (if possible). For example:

    &lt;component type=&quot;A&quot; binding=&quot;B&quot;&gt;
      &lt;operation name=&quot;X&quot;&gt;
        &lt;input type=&quot;C&quot; /&gt;
      &lt;/operation&gt;

      &lt;event name=&quot;Y&quot;&gt;
        &lt;output type=&quot;D&quot; /&gt;
      &lt;/event&gt;
    &lt;/component&gt;

As you can see, both elements component, operation and event have both attributes and child element. Is it possible to define this in XSD? How?

Thank you very much!

XSD element with both attributes and child elements

I&#39;m having a hard time with the XSD files.

I&#39;m trying to create an XSD file from a class:

    public enum Levels { Easy, Medium, Hard }
    public sealed class Configuration
    {
        public string Name { get;set; }
        public Levels Level { get; set; }
        public ConfigurationSpec { get;set;}
    }

    public abstract class ConfigurationSpec { }
    public class ConfigurationSpec1
    {
        // ...
    }
    public class ConfigurationSpec2
    {
        // ...
    }

Please note that I have an abstract class inside of Configuration. With that feature, is it possible to create the XSD and if it&#39;s possible how?

The idea is to pass the class Configuration to the XSD.

How to create a XSD schema from a class?

I have been working on a REST web service using Jersey for a few days now, and managed to have all CRUD operations working, with several exchange formats: XML, JSON, Google Protobuf.

However I am facing some issues related to automatically generated WADL and XSD.

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#Context

To define the objects exchanged in these three formats, I have followed a **&quot;contract-first&quot; approach**:

 - from a XSD I wrote, I generated my model classes using JAXB;
 - from an equivalent proto file I wrote, I generated the Google Protobuf classes (and internally have a way to convert these to the JAXB-generated objects, in order to have one unique model).

However, as I would like my users to be able to **generate their classes** too, I would like to share these schema files (.xsd and .proto) and have them **well integrated with the automatically generated WADL**.

For that purpose, thanks to [this][1] wiki page:

 - I have exposed the two files under
  - `/schema/schema.xsd`
  - `/schema/schema.proto`
 - I have added an application-grammar file:

        &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; standalone=&quot;yes&quot;?&gt;
        &lt;grammars xmlns=&quot;http://wadl.dev.java.net/2009/02&quot; 
                  xmlns:xsd=&quot;http://www.w3.org/2001/XMLSchema&quot;
                  xmlns:xi=&quot;http://www.w3.org/1999/XML/xinclude&quot;&gt;
            &lt;include href=&quot;../schema/schema.xsd&quot; /&gt;
        &lt;/grammars&gt;

 - I have added a customized WADL generator:

         public class RichWadlGeneratorConfig extends WadlGeneratorConfig {
            @Override
            public List&lt;WadlGeneratorDescription&gt; configure() {
                return generator(WadlGeneratorApplicationDoc.class)
                    .prop(&quot;applicationDocsStream&quot;, &quot;application-doc.xml&quot;)
                    .generator(WadlGeneratorGrammarsSupport.class)
                    .prop(&quot;grammarsStream&quot;, &quot;application-grammars.xml&quot;)
                    .descriptions();
            }
         }

This way the below appears in the WADL, when I hit `/rest/application.wadl`:

    &lt;grammars&gt;
         &lt;include href=&quot;../schema/schema.xsd&quot;/&gt;
         &lt;include href=&quot;application.wadl/xsd0.xsd&quot;&gt;
              &lt;doc title=&quot;Generated&quot; xml:lang=&quot;en&quot;/&gt;
         &lt;/include&gt;
    &lt;/grammars&gt;

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#Problem

`/rest/application.wadl/xsd0.xsd` is automatically generated from my classes, but is quite **different** from what I initially had in `schema.xsd`.
In addition to that, calling a tool like `wadl2java` on this WADL fails miserably, presumably because

 - `/schema/schema.xsd`, and
 - `/rest/application.wadl/xsd0.xsd`

are now conflicting (two definitions for the same objects).

----------

#Questions

 1. Is there a way to disable the generation and diffusion of this automatically generated XSD? 
    (As I don&#39;t need it since I&#39;m following this &quot;contract-first&quot; approach)

 2. If not, is there a way to &quot;override&quot; its content with my manually written XSD when `/rest/application.wadl/xsd0.xsd` is hit?
    (I have googled around and found about WadlResource, to generate customized WADL, but found nothing about the XSD generation itself)

----------

Thanks in advance for your help!

M.

----------

#Edit

1) I raised the issue to the Jersey team and got a reply:
[http://java.net/projects/jersey/lists/users/archive/2012-06/message/8][2]

2) I raised a ticket (JERSEY-1230), according to Pavel&#39;s instructions.
I am currently following up to either submit a fix myself or get a fix from the Jersey team.


  [1]: https://wikis.oracle.com/display/Jersey/HowToConfigureExtendedWADL
  [2]: http://java.net/projects/jersey/lists/users/archive/2012-06/message/8

Troubles with WADL / generated XSD using Jersey with a contract-first approach

I used the second solution of
[https://stackoverflow.com/questions/179927/how-to-resolve-could-not-find-schema-information-for-the-element-attribute-xxx][1]

I.e. created a XSD with the button to create a scheme. I changed the stylesheet in app.config to app.xsd but now I get the warning:

   The Global element &#39;configuration&#39; has already been declared in app.xsd

Even when changing the name the warning is shown.
Does anybody have a solution for this?



  [1]: https://stackoverflow.com/questions/179927/how-to-resolve-could-not-find-schema-information-for-the-element-attribute-xxx

Content Type	Original Author	Original Content on Stackoverflow
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Solution 1 - Xml	Dmitry Kudryavtsev	View Answer on Stackoverflow
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