4.5. < AppML > reference manual

发布时间 ： 2025-10-25 13:33:38 UTC      

Page Views: 31 views

4.5.1. < AppML > data model: 

<appml security="security">

<datasource>
Datasource definition goes here
datasource>

<filters>
Filter definitions goes here (if any)
filters>

<update>
Update definitions goes here (if any)
update>

<anything>
Anything you want to add to the model
anything>

appml>
    
 
  4.5.2.  < AppML > Security  
 
 < AppML > Security is set through the security attribute in the < AppML > tag. 
 
 
 
<appml security="artists">

 
 
 
 The above application begins with security definition attributes, and only artists users are allowed to log in. 
 
 In this case, the user name logged in must be a member of the “artists” group. 
 
 
 
  4.5.3.  < datasource > element  
 
 The < datasource > element applied by < AppML > defines four different data types: 
 
 
 Child element (only one can be applied)  
 
  
  
 element 
 		  
 Description 
 		 
   
  
 < database > 
 		  
 Define data types 
 		 
 
  
 < xmlfile > 
 		  
 Define XML source files 
 		 
 
  
 < csvfile > 
 		  
 Define a comma-delimited text file 
 		 
  
 
 
 
 
  4.5.4.  < database > element  
 
 The < database > element defines the database 
 
 
 Child element  
 
  
  
 element 
 		  
 Description 
 		 
   
  
 < connection > 
 		  
 Link database name 
 		 
 
  
 < execute > 
 		  
 SQL statement executed before data retrieval (optional) 
 		 
 
  
 < sql > 
 		  
 SQL statements for retrieving data 
 		 
 
  
 < maintable > 
 		  
 Master table of the application (optional) 
 		 
 
  
 < keyfield > 
 		  
 Key field of the main table (optional) 
 		 
  
 
 
 
 
  4.5.5.  Data stored in the SQL database  
 
 This is the most common solution for data-oriented applications. 
 
 
 
<datasource>
<database>
<connection>CDDataBaseconnection>
<sql>SELECT Artist, Title, Country FROM CD_Catalogsql>
database>
datasource>
   
 The above model can select three data options (Artist, Title, Country) from the “CD_Catalog” table of the “CDDataBase” database. 
 
 The number of rows returned as a result is unknown. 
  
 
  4.5.6.  Data stored in XML files  
 
 < AppML > can read data from a XML file: 
 
 
 Example  
 
 
 
<appml>

<datasource>
<xmlfile src="cd_catalog.xml">

<record>CDrecord>

<item>
<name>Titlename>
<nodename>TITLEnodename>
item>

<item>
<name>Artistname>
<nodename>ARTISTnodename>
item>
<item>

<name>Countryname>
<nodename>COUNTRYnodename>
item>

xmlfile>
datasource>

appml>
   
  尝试一下 »  
 
 This method stores data in a XML file on the server. 
   
 
  4.5.7.  Data is stored in a text (Text) file  
 
 < AppML > can read data from a text file: 
 
 
 Example  
 
 
 
<appml>
<datasource>
<csvfile src="cd_catalog.txt">
<item>
<name>Titlename>
<index>1index>
item>
<item>
<name>Artistname>
<index>2index>
item>
<item>
<name>Pricename>
<index>5index>
item>
csvfile>
datasource>
appml>
   
  尝试一下 »  
 
 This method can store data in a text file on the server. 
   
 
  4.5.8.  You can create a database if you want.  
 
 < AppML > you can create a database if necessary: 
 
 
 
<database>
<connection>CDDataBaseconnection>
<execute>
CREATE TABLE CD_catalog (
CD_Id INT IDENTITY,
Title NVARCHAR(255),
Artist NVARCHAR(255),
Country NVARCHAR(255),
Company NVARCHAR(255),
Price NUMBER,Published INT)
execute>
database>
   
 Perfect the rapid prototyping model! 
   
                    
                
                

                    

                        

                            
                                文章链接
                            
                            ：
                            4.5. < AppML > reference manual 
                        

                    

                

            
        
        

            

    
        

            

                

                    
                        
                        
                            
Principles and Applications of WebGIS 

                        
                        
                             37
                        
                    
                    
                        

                            
 
 
 

                        

                    
                

                
            

        

    

    
        

            

                

                    
                        
                        
                            
Web框架 

                        
                        
                             942
                        
                    
                    
                        

                            
 
 
 

                        

                    
                

                
            

        

    

    
        

            

                

                    
                        
                        
                            
WEB基础 

                        
                        
                             287
                        
                    
                    
                        

                            
 
 
 

                        

                    
                

                
            

        

    

    
        

            

                

                    
                        
                        
                            
Principles, Technologies, and Methods of Geographic Information Systems 

                        
                        
                             102
                        
                    
                    
                        

                            
 
 
 In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.