Author: fmantek
Date: Thu Jun 28 05:19:38 2007
New Revision: 197
Modified:
trunk/clients/cs/tips.txt
Log:
made file look better in Windows
Modified: trunk/clients/cs/tips.txt
==============================================================================
--- trunk/clients/cs/tips.txt (original)
+++ trunk/clients/cs/tips.txt Thu Jun 28 05:19:38 2007
@@ -1,193 +1,193 @@
-Tip One:
-One of the things that allways show up here on the newsgroups, is the problem
to
-figure out why an execution to the server failed. In general, this is rather
-simplistic to deal with on the C# side, but as not everyone is familiar with
the
-process, here is the scoop.
-
-When the webserver returns an error, an exception will be thrown. The C# client
-code will catch this, package it into a GDataRequestException and throw that
-one.
-
-In the application code, therefore, when you do something like:
-
-myFeed.Insert(myNewEntry);
-
-what you should be doing is:
-
-
-try {
- myFeed.Insert(myNewEntry);
-} catch (GDataRequestException e ) {
-// your error code here
-}
-
-
-In general, the GDataRequestException class is just a wrapper around the real
-exception. It has the innerException, and it exposes the WebResponse, the
object
-that captures the server response, as a property named Response.
-
-A WebResponse now has a bundle of properties, including a method
-GetResponseStream, which you can use to get the real HTTP/Text that the server
-returned. If you cast the WebResponse to an HttpWebResponse, you can get the
-StatusCode and other, more HTTP specific information as well.
-
-To make life easier, i just added a ResponseString property to the
-GDataRequestException class, so that you can easier glance at additonal
-information returned by the server. For those not at ease with the repository,
-here is code that does the same in an exception handler:
-
-catch (GDataRequestException e) {
- Stream receiver = e.Response.GetResponseStream();
- if (receiver != null) {
- // Pipe the stream to ahigher level stream reader with the default encoding
- // format. which is UTF8
- StreamReader readStream = new StreamReader(receiver);
-
- // Read 256 charcters at a time.
- char []buffer = new char[256];
- StringBuilder builder = new StringBuilder(1024);
- int count = readStream.Read( buffer, 0, 256);
- while (count > 0) {
- string onto the console. builder.Append(buffer);
- count = readStream.Read(buffer,0, 256);
- }
-
- // Release the resources of stream object.
- readStream.Close();
- receiver.Close();
- responseText = builder.ToString();
- }
-}
-
-At the end of the code, responseText will hold the complete HTTP/Text response
-of the server. It might be safer to even check of the contenttype, before using
-that string AS a string, but for debugging purposes this will do just fine.
-
-
-Tip Two:
-Understanding the Unknown
-
-As you might have noticed, there are always new elements appearing in the atom
-streams of properties, extensions that are useful to the individual property,
-and therefore, useful to at least some of the developers working with those
-properties.
-
-One example for this is the draft element in the beta.blogger.com feeds. The
-draft element is a subelement of an atom:entry, and looks pretty much like
this:
-
-<entry xmlns:app='http://purl.org/atom/app#'>
- ...
- <app:control>
- <app:draft>yes</app:draft>
- </app:control>
-</entry>
-
-What this does, for blogger, is, it marks this entry as a draft, as not yet
-finished.
-
-Now this is all well, but, if you are using a premade library to deal with
-the content, how do you suddenly insert a new element? You can obviously wait
-for an updated release, that supports this new element. Or, you can do it
-yourself.
-
-For this, you need to understand a little bit about the way the current parser
-works. The parser is based on XmlReader, not the XmlDom, and parses the stream
-using the XmlReader interfaces to encounter all the Atom/GData elements. For
-things the parser understands, he creates the corresponding objects, like
-AtomEntry, and fills the properties of that object.
-
-But what happens with things that are not understood? They end up as an
element
-of the ExtensionElements collection, that is a member of all classes inherited
-from AtomBase, like AtomFeed, AtomEntry, EventEntry etc...
-
-That means for something like a blogger entry that would have an app:control
-element in it, that this xml snippet is not lost. It's only not directly
exposed
-as a property, but, instead, converted into an XmlNode and then put into
-the ExtensionElements collection.
-
-This can actually be intercepted, by hooking the FeedParserEventHandler (which
-fires events when new elements are created) and the
ExtensionElementEventHandler
-(which fires events when unknown entities are encountered). By intercepting and
-overriding the default behaviour you are able to substitute your own objects
-for the default objects created. This is the way the CalendarFeed/EventEntry
-are implemented, and all other extensions as well.
-
-But, this is a more advanced topic for another time. Back to the
ExtensionElments
-collection. Everything in that collection is potentially persisted. If it is an
-XmlNode object, or if it is inheriting from IExtensionElement, it will be
saved
-into the xml stream when it's owner is persisted.
-
-Hence to figure out if a certain attribute is set you can do something like
this:
-
- foreach (Object obj in entry.ExtensionElements)
- if obj is XmlNode
- ... check whatever it is you are looking for
-
-
-
-If also means that the following code:
-
- XmlNode node = new XmlNode(
- "<app:control xmlns:app='http://purl.org/atom/app#>
- <app:draft>yes</app:draft>
- </app:control>"
-
- AtomEntry entry = ....
- entry.ExtensionElements.Add(node);
-
- entry.Update();
-
- will create the required xml during the update/insert process to indicate
- this to be a draft element.
-
- Hope that was helpful.
-
-
-Tip Three:
-
-One of the new features in the Google Calendar service is the ability to embed
web content
-in the UI (see here:
http://googleblog.blogspot.com/2006/09/google-calendar-does-something-about.html).
-
-Essentially, what you need to do is to create an atom:link, with a
gcal:webContent
-child element of the following form:
-
-<atom:link rel="http://schemas.google.com/gCal/2005/webContent";
- title="Your Title"
- href="a link to an icon for the top of the day">
- type="text/html or image/*"
- <gCal:webContent url="a link to the content"
- width="pixels"
- height="pixels" />
-</atom:link>
-
-If type is text/html, the content will be displayed in an IFrame, if it's
image/*, an IMG
-element will be used.
-
-There is samplecode in cs/src/unittests/caltest.cs, here is the relevant part
to show you how easy it is to set this up:
-
- EventEntry entry = ...
-
- AtomLink link = new AtomLink("image/gif",
"http://schemas.google.com/gCal/2005/webContent";);
- link.Title = "Test content";
- link.HRef =
"http://www.google.com/calendar/images/google-holiday.gif";;
- WebContent content = new WebContent();
- content.Url = "http://www.google.com/logos/july4th06.gif";;
- content.Width = 270;
- content.Height = 130;
- link.ExtensionElements.Add(content);
- entry.Links.Add(link);
-
- entry.Update(..
-
-That's it. Play with it and enjoy the visual effects you can create for your
calendar that way.
-
-
-
-
-
-
-
-
-
-
+Tip One:
+One of the things that allways show up here on the newsgroups, is the problem
to
+figure out why an execution to the server failed. In general, this is rather
+simplistic to deal with on the C# side, but as not everyone is familiar with
the
+process, here is the scoop.
+
+When the webserver returns an error, an exception will be thrown. The C# client
+code will catch this, package it into a GDataRequestException and throw that
+one.
+
+In the application code, therefore, when you do something like:
+
+myFeed.Insert(myNewEntry);
+
+what you should be doing is:
+
+
+try {
+ myFeed.Insert(myNewEntry);
+} catch (GDataRequestException e ) {
+// your error code here
+}
+
+
+In general, the GDataRequestException class is just a wrapper around the real
+exception. It has the innerException, and it exposes the WebResponse, the
object
+that captures the server response, as a property named Response.
+
+A WebResponse now has a bundle of properties, including a method
+GetResponseStream, which you can use to get the real HTTP/Text that the server
+returned. If you cast the WebResponse to an HttpWebResponse, you can get the
+StatusCode and other, more HTTP specific information as well.
+
+To make life easier, i just added a ResponseString property to the
+GDataRequestException class, so that you can easier glance at additonal
+information returned by the server. For those not at ease with the repository,
+here is code that does the same in an exception handler:
+
+catch (GDataRequestException e) {
+ Stream receiver = e.Response.GetResponseStream();
+ if (receiver != null) {
+ // Pipe the stream to ahigher level stream reader with the default encoding
+ // format. which is UTF8
+ StreamReader readStream = new StreamReader(receiver);
+
+ // Read 256 charcters at a time.
+ char []buffer = new char[256];
+ StringBuilder builder = new StringBuilder(1024);
+ int count = readStream.Read( buffer, 0, 256);
+ while (count > 0) {
+ string onto the console. builder.Append(buffer);
+ count = readStream.Read(buffer,0, 256);
+ }
+
+ // Release the resources of stream object.
+ readStream.Close();
+ receiver.Close();
+ responseText = builder.ToString();
+ }
+}
+
+At the end of the code, responseText will hold the complete HTTP/Text response
+of the server. It might be safer to even check of the contenttype, before using
+that string AS a string, but for debugging purposes this will do just fine.
+
+
+Tip Two:
+Understanding the Unknown
+
+As you might have noticed, there are always new elements appearing in the atom
+streams of properties, extensions that are useful to the individual property,
+and therefore, useful to at least some of the developers working with those
+properties.
+
+One example for this is the draft element in the beta.blogger.com feeds. The
+draft element is a subelement of an atom:entry, and looks pretty much like
this:
+
+<entry xmlns:app='http://purl.org/atom/app#'>
+ ...
+ <app:control>
+ <app:draft>yes</app:draft>
+ </app:control>
+</entry>
+
+What this does, for blogger, is, it marks this entry as a draft, as not yet
+finished.
+
+Now this is all well, but, if you are using a premade library to deal with
+the content, how do you suddenly insert a new element? You can obviously wait
+for an updated release, that supports this new element. Or, you can do it
+yourself.
+
+For this, you need to understand a little bit about the way the current parser
+works. The parser is based on XmlReader, not the XmlDom, and parses the stream
+using the XmlReader interfaces to encounter all the Atom/GData elements. For
+things the parser understands, he creates the corresponding objects, like
+AtomEntry, and fills the properties of that object.
+
+But what happens with things that are not understood? They end up as an
element
+of the ExtensionElements collection, that is a member of all classes inherited
+from AtomBase, like AtomFeed, AtomEntry, EventEntry etc...
+
+That means for something like a blogger entry that would have an app:control
+element in it, that this xml snippet is not lost. It's only not directly
exposed
+as a property, but, instead, converted into an XmlNode and then put into
+the ExtensionElements collection.
+
+This can actually be intercepted, by hooking the FeedParserEventHandler (which
+fires events when new elements are created) and the
ExtensionElementEventHandler
+(which fires events when unknown entities are encountered). By intercepting and
+overriding the default behaviour you are able to substitute your own objects
+for the default objects created. This is the way the CalendarFeed/EventEntry
+are implemented, and all other extensions as well.
+
+But, this is a more advanced topic for another time. Back to the
ExtensionElments
+collection. Everything in that collection is potentially persisted. If it is an
+XmlNode object, or if it is inheriting from IExtensionElement, it will be
saved
+into the xml stream when it's owner is persisted.
+
+Hence to figure out if a certain attribute is set you can do something like
this:
+
+ foreach (Object obj in entry.ExtensionElements)
+ if obj is XmlNode
+ ... check whatever it is you are looking for
+
+
+
+If also means that the following code:
+
+ XmlNode node = new XmlNode(
+ "<app:control xmlns:app='http://purl.org/atom/app#>
+ <app:draft>yes</app:draft>
+ </app:control>"
+
+ AtomEntry entry = ....
+ entry.ExtensionElements.Add(node);
+
+ entry.Update();
+
+ will create the required xml during the update/insert process to indicate
+ this to be a draft element.
+
+ Hope that was helpful.
+
+
+Tip Three:
+
+One of the new features in the Google Calendar service is the ability to embed
web content
+in the UI (see here:
http://googleblog.blogspot.com/2006/09/google-calendar-does-something-about.html).
+
+Essentially, what you need to do is to create an atom:link, with a
gcal:webContent
+child element of the following form:
+
+<atom:link rel="http://schemas.google.com/gCal/2005/webContent";
+ title="Your Title"
+ href="a link to an icon for the top of the day">
+ type="text/html or image/*"
+ <gCal:webContent url="a link to the content"
+ width="pixels"
+ height="pixels" />
+</atom:link>
+
+If type is text/html, the content will be displayed in an IFrame, if it's
image/*, an IMG
+element will be used.
+
+There is samplecode in cs/src/unittests/caltest.cs, here is the relevant part
to show you how easy it is to set this up:
+
+ EventEntry entry = ...
+
+ AtomLink link = new AtomLink("image/gif",
"http://schemas.google.com/gCal/2005/webContent";);
+ link.Title = "Test content";
+ link.HRef =
"http://www.google.com/calendar/images/google-holiday.gif";;
+ WebContent content = new WebContent();
+ content.Url = "http://www.google.com/logos/july4th06.gif";;
+ content.Width = 270;
+ content.Height = 130;
+ link.ExtensionElements.Add(content);
+ entry.Links.Add(link);
+
+ entry.Update(..
+
+That's it. Play with it and enjoy the visual effects you can create for your
calendar that way.
+
+
+
+
+
+
+
+
+
+
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![http://www.google.com/calendar/images/google-holiday.gif"](https://www.google.com/calendar/images/google-holiday.gif"){kind=link}
![http://www.google.com/logos/july4th06.gif"](https://www.google.com/logos/july4th06.gif"){kind=link}