DWR Note 2

Last Update:2018-12-05 Source: Internet

Author: User

Developer on Alibaba Coud: Build your first app with APIs, SDKs, and tutorials on the Alibaba Cloud. Read more ＞

Matching Java objects with JavaScript objects
Public Class Remote {
Public void setperson (person p ){
This. Person = P;
}
}

And classes person looks like this:
Public person {
Private string name;
Private int age;
Private date [] appointments;
// Getters and setters... be sure to add getter and setter
}

// Then you can call this from JavaScript like this:
VaR P = {
Name: "Fred Bloggs ",
Age: 42,
Appointments: [new date (), new date ("1 Jan 2008")]
};
Remote. setperson (P );

Because setperson () is modified using void, callback is not required in Javascript, even if you write a callback function
And DWR will not pass any value back.
You can also write
Remote. setperson (null, P );

Asynchronous loading prompt
The DWR standard displays Gmail-style loading message prompts. You can call
The loading message prompts, but it cannot be called before page onload. Because the loading principle still uses an hide
To accommodate loading messages.
In DWR, you can complete the Gmail-style loading settings with only one simple step.
<Head>
<SCRIPT>
Function Init (){
Dwrutil. useloadingmessage ();
}
</SCRIPT>
...
</Head>
<Body onload = "Init ();">

Of course, you may not be able to modify the <body> element in the CMS mode.
<SCRIPT>
Function Init (){
Dwrutil. useloadingmessage ();
}

If (window. addeventlistener ){
Window. addeventlistener ("LOAD", init, false );
}
Else if (window. attachevent ){
Window. attachevent ("onLoad", init );
}
Else {
Window. onload = Init;
}
</SCRIPT>

You can also dynamically create a layer (with ID = "disabledzone") that contains a prompt message.
Below are two improved programs

The first one allows you to modify your own prompt message
Function useloadingmessage (Message ){
VaR loadingmessage;
If (Message) loadingmessage = message;
Else loadingmessage = "loading ";

Dwrengine. setprehook (function (){
VaR disabledzone = $ ('disabledzone ');
If (! Disabledzone ){
Disabledzone = Document. createelement ('div ');
Disabledzone. setattribute ('id', 'disabledzone ');
Disabledzone. style. Position = "absolute ";
Disabledzone. style. zindex = "1000 ";
Disabledzone. style. Left = "0px ";
Disabledzone. style. Top = "0px ";
Disabledzone. style. width = "100% ";
Disabledzone. style. Height = "100% ";
Document. Body. appendchild (disabledzone );
VaR messagezone = Document. createelement ('div ');
Messagezone. setattribute ('id', 'messagezone ');
Messagezone. style. Position = "absolute ";
Messagezone. style. Top = "0px ";
Messagezone. style. Right = "0px ";
Messagezone. style. Background = "red ";
Messagezone. style. color = "white ";
Messagezone. style. fontfamily = "Arial, Helvetica, sans-serif ";
Messagezone. style. Padding = "4px ";
Disabledzone. appendchild (messagezone );
VaR text = Document. createtextnode (loadingmessage );
Messagezone. appendchild (text );
}
Else {
$ ('Messagezone'). innerhtml = loadingmessage;
Disabledzone. style. Visibility = 'visable ';
}
});

Dwrengine. setposthook (function (){
$ ('Disabledzone '). style. Visibility = 'ddn ';
});
}

2nd images can be used as prompt messages
Function useloadingimage (imagesrc ){
VaR loadingimage;
If (imagesrc) loadingimage = imagesrc;
Else loadingimage = "ajax-loader.gif ";
Dwrengine. setprehook (function (){
VaR disabledimagezone = $ ('disabledimagezone ');
If (! Disabledimagezone ){
Disabledimagezone = Document. createelement ('div ');
Disabledimagezone. setattribute ('id', 'disabledimagezone ');
Disabledimagezone. style. Position = "absolute ";
Disabledimagezone. style. zindex = "1000 ";
Disabledimagezone. style. Left = "0px ";
Disabledimagezone. style. Top = "0px ";
Disabledimagezone. style. width = "100% ";
Disabledimagezone. style. Height = "100% ";
VaR imagezone = Document. createelement ('img ');
Imagezone. setattribute ('id', 'imagezone ');
Imagezone. setattribute ('src', imagesrc );
Imagezone. style. Position = "absolute ";
Imagezone. style. Top = "0px ";
Imagezone. style. Right = "0px ";
Disabledimagezone. appendchild (imagezone );
Document. Body. appendchild (disabledimagezone );
}
Else {
$ ('Imagezone'). src = imagesrc;
Disabledimagezone. style. Visibility = 'visible ';
}
});
Dwrengine. setposthook (function (){
$ ('Disabledimagezone'). style. Visibility = 'hiddy ';
});
}

Dwrutil. todescriptivestring () is used for any HTML control on the debug page.
Dwrutil. todescriptivestring (P1, P2)
P1 indicates the ID of the control you want to bebug
P2 (Int = {0, 1, 2 })
Where 0, the single line debugging information is returned.
1/2 return multi-line debugging information

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

Get Started for Free

Sales Support

1 on 1 presale consultation

Chat Contact Sales
After-Sales Support

24/7 Technical Support 6 Free Tickets per Quarter Faster Response

Open a Ticket
Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.

Learn More