Comparing Mashup Platforms Using JSON & MySQL - Part 2 - Process JSON

30 03 2007

Technologies Used: PHP 5, MySQL 4.1.2, JavaScript, JSON

Software Used: PHP Designer, Aptana, Firebug, Firefox

There are a wide variety of ways to handle JSON that is returned from a server. One of these methods is to provide a callback function pass it to the JSON emiting webservice via REST. When used with static or dynamic script tags, you are no longer restricted to Cross Site Scripting (XSS) limits requireing that the source be on the same server as your webpage. The XSS limit seems particularly ill-suited for mash-ups. The callback function method is what I have choosen for my examples. You will also see a static script tag for these examples. That is to simplify them and make them easier to read. The general preference is to use dynamic script tags rather than static ones.

Actual JSON string returned:

handleJSON({”Observations”:[{"Station":{"number":"1","lat":"29.5762","lon":"-98.7041","total_sp":"9","Species":[{"common":"Mourning Dove","number":"1","code":"MODO","scientific":"Zenaida macroura"},{"common":"Eastern Phoebe","number":"1","code":"EAPH","scientific":"Sayornis phoebe"},{"common":"Carolina Chickadee","number":"1","code":"CACH","scientific":"Poecile carolinensis"},{"common":"Black-crested Titmouse","number":"3","code":"BCTI","scientific":"Baeolophus atricristatus"},{"common":"Carolina Wren","number":"1","code":"CARW","scientific":"Thryothorus ludovicianus"},{"common":"Bewick's Wren","number":"2","code":"BEWR","scientific":"Thryomanes bewickii"},{"common":"Rufous-crowned Sparrow","number":"1","code":"RCSP","scientific":"Aimophila ruficeps"},{"common":"Northern Cardinal","number":"3","code":"NOCA","scientific":"Cardinalis cardinalis"},{"common":"Brown-headed Cowbird","number":"1","code":"BHCO","scientific":"Molothrus ater"}]}},{”Station”:{”number”:”2″,”lat”:”29.574″,”lon”:”-98.7036″,”total_sp”:”5″,”Species”:[{"common":"Black-crested Titmouse","number":"1","code":"BCTI","scientific":"Baeolophus atricristatus"},{"common":"Carolina Wren","number":"1","code":"CARW","scientific":"Thryothorus ludovicianus"},{"common":"Ruby-crowned Kinglet","number":"1","code":"RCKI","scientific":"Regulus calendula"},{"common":"Northern Cardinal","number":"1","code":"NOCA","scientific":"Cardinalis cardinalis"},{"common":"Brown-headed Cowbird","number":"1","code":"BHCO","scientific":"Molothrus ater"}]}}]});

It is not very human readable, but it is highly machine readable.

Below is an extremely simple example of handling JSON and doing something with it.

<html>
<head>
<meta http-equiv=“Content-Type” content=“text/html; charset=iso-8859-1″ />
<title>Simple JSON Handling</title>
<script type=”text/javascript” charset=”utf-8″>
function showCoords(jsd){
var lat = jsd.Observations[0].Station.lat;
var lon = jsd.Observations[0].Station.lon;
var msg = ‘Lat:’ + lat + ‘, Lon:’ + lon;
alert(msg);
}
</script>
</head>
<body>
<script src=http://www.plateauwildlife.com/bbc-mgmt/getstations.php?action=getdata&cid=2&year=2006&func=showCoords type=”text/javascript” charset=”utf-8″></script>
</body>
</html>



See It In Action


The above example is not particulalry usefull for anything other than demostration purposes. We want to actually DO something with our JSON to move us closer to creating the actual mashup. The number thing which I intially strugled with when using JSON & callback functions was that you MUST define the callback function BEFORE your dynamic or static script tag.


Google Maps, Google Earth, Yahoo Maps, and Virtual Earth all take HTML for the contents of the info window when you rollover or click on a point.


ArcWeb Explorer (AWX), however doesn’t take HTML as info window content. AWX does take styled text, videos, picture, audio, & swf for info window content. To this end, if you want to embed rich non-HTML content, AWX allows for some extremelly interesting content to be blended together and presented with great ease. The documentation for text styling is lacking, so creating simple content is actually more dificult in this platform than the others.


I’ve created a javascript file which we can reference in any of the HTML docs that actually embed the mashup.


This file contains


    

  1. The main callback function
    2. 

  2. A function which builds an array of HTML tables containing the formated results from each station
    3. 

  3. A function which builds an array of jscript strings containg the weakly formated results from each station
    4. 



See The HTML Builder In Action






    //A global variable to assign the parsed JSON to


var jsobj;


 


//Main Callback handler.


//simple assignment to a global variable allows me to reuse and pass


//around the object without any server trips


function handleJSON(reply){


    jsobj=reply;


}


 


    function buildHTML(Observations){


    var info_win = new Array();


    // Build a table element with Station number & total species observed


    for(var i=0;i<Observations.length;i++){


        str = ‘<table border=”1″><tbody><tr class=”station”>’;


        str += ‘<td colspan=”2″>Station ‘+ Observations[i].Station.number + ‘</td></tr>’;


        str += ‘<tr class=”sta_total”><td colspan=”2″>Total Species - ‘ + Observations[i].Station.total_sp + ‘</td></tr>’;


       str += ‘<tr class=”obs_header”><td>Species</td><td>Number</td></tr>’;


        var details = “”;


        var arr = new Array();


        // assign each Species array to a local variable to reduce typing & increase readibility


        //build an string of <tr> elements containing the details of species observed


        arr = Observations[i].Station.Species;


            for (var y=0;y<arr.length;y++){


            details+=‘<tr class=”obs_detail”><td><a href=”http://www.google.com/search?q=%22′;


            details += arr[y].scientific.replace(/\s/,“+”);


            details += ‘%22″>’ + arr[y].common + ‘ (’ + arr[y].code + ‘)</a></td>’;


            details += ‘<td>’ + arr[y].number + ‘</td></tr>’;


            }


        str +=    details;


        str += ‘</table></tr></tbody></table>’;


        //add table element to array of table element html strings


        info_win[i]=str;


    }


return info_win;


}


 


function buildAWXtxt(Observations){


        var info_win = new Array();


    // Build a formated text list for each Station number & total species observed


    for(var i=0;i<Observations.length;i++){


        str = ‘Station ‘ + Observations[i].Station.number + ‘\n’;


        str += ‘Total Species - ‘ + Observations[i].Station.total_sp + ‘\n’;


       str += ‘Species          Number’;


        var details = new Array();


        // assign each Species array to a local variable to reduce typing & increase readibility


        //build an array formatted text data elements containing the details of species observed


        //using this convention, we can assign a url property to each species line


        //through .data{elements[]} in the properties for each marker 


        arr = Observations[i].Station.Species;


            for (var y=0;y<arr.length;y++){


            details[y] = arr[y].common + ‘ (’ + arr[y].code + ‘) - ‘ + arr[y].number + ‘\n’;


            }


        var obs_info = new Array([str,details]);


        //


        //add table element to array of table element html strings


        info_win[i]=obs_info;


    }


return info_win;


}




 


Previous Parts


1. Emit JSON


 


Next Parts


3. Arcweb Explorer Mashup


4. Yahoo Maps Mashup


5. Virtual Earth Mashup


6. Google Maps Mashup


				

				
								
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				Categories : AWX,  ArcWeb Mapping,  General Programming,  JSON,  Mashup,  MySQL,  Open Source,  PHP,  Survey Management,  Walkthroughs or Tutorials,  Web Development Tools,  Web Mapping
						
			

				
		

			
						
			

				
				
JetDbConnect - a class providing a simplified interface to JET OleDb compatible datasources using ADO.Net

				
					26
					03
					2007
				
				
				

					
I needed a way to run SQL queries on structured text files & Excel files. 


Download links available at end of post


For the last few months, I have been toiling away in the highly arcane world of fixed width text files. Very large ones at that (250-500mb). These come from text file data dumps of appraisal district databases. I need only a subset of these records. From there they go into Excel where they are cleaned up on a nearly line by line basis that can’t be handled consistently by RegEx since data is recorded so differently by each county. From there I want to summarize that data on a single household basis. I could go in Excel & do:


    

  1. Advanced filter, Unique Values (based on a unique household identifier)

  2. Use vlookup & sumif functions to copy and/or sum the data for each column
    3. 



However, this is rather time consuming since different data is provided by in different order and level of detail for each county. Also, for rolls with more than 25k records and over 100 fields these Excel formulas can take ~30min to complete. You then need to copy & paste values or you’ll have to wait a long time anytime a recalc is performed. Needed a programmatic way to deal with this data and to minimize the human time to just records which required actual human eyes to modify.


Admittedly, creating an OleDb connection, command, reader & even datatable using ADO.Net methods is a pretty simple thing. 


Dim connect As New OleDb.OleDbConnection
Dim strConnect As String = “Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\MyExcel.xls;Extended Properties=”"Excel 8.0;HDR=Yes;IMEX=1″”"
connect.ConnectionString = strConnect
Dim cmd As New OleDb.OleDbCommand(”SELECT * FROM [Sheet1$] WHERE City=’Austin’ AND LandValue > 30000″, connect)
Dim reader As OleDb.OleDbDataReader = cmd.ExecuteReader()
Dim dt As New DataTable
dt.Load(reader)




But I wanted something even simpler & significantly more flexible than that. I wanted an object that could handle any potential Jet datasource, field list, target table, and SQL Select statement. I wanted something that could be reused in a variety of different applications and not require any hard coding of these parameters or make me implement different ways to do this in each application. I needed a good object oriented design with high reusability. To this end I created the JetDbConnect.dll


Structure


 


Properties


    

  • Closed - OleDbConnection closed or open

  • ConnectionString (ReadOnly)

  • DataSource - the file path to your Jet compatible datasource. The ONLY property you must set either by assignment or through instantiation.

  • DbConnection (ReadOnly)

  • ExtendedProperties - if you need to use a Jet datasource that is not directly supported, here is where you would give the connection string parameters that would allow you to use it

  • StorageMethod - one of the 4 enums of the file types this handles directly (Text, Excel, Access, Dbase). Should never need to be set unless you have a really messed up filename.

  • TablesList - List of Strings of available tables in the datasource

  • TargetTable - The table from which to query data, only needed in Excel & Access. If not given for those then it picks 1st table on table list

  • TextFormat - enum: FixedWidth or Delimited. If not set assumes delimited with default delimiter set in your registry settings
    • 



Methods


    

  • New

      

    • () - Default

    • (DataSource as string, TextFormat Enum)

        

      • This is used ONLY with text-based datasources

      • DataSource = path to datasource

      • TextFormat Enum is one of the 2 members of this Enum
        • 

      

    • (DataSource as string, [TargetTable] as string)

        

      • This can be used with any datasource type.

      • If you use it with a text-based datasource, and it is not delimited with your default delimiter, then you will also have to set the TextFormat enum elsewhere BEFORE using one of the Command,Reader, or Records methods
        • 

      

      • 

    

  • Close() - manually close the connection. Not required but can be useful

  • CommandGetAll, ReaderGetAll, RecordsGetAll ([DataSource] as string, [TargetTable] as string)

      

    • All 3 methods take the same parameters, an optional datasource path and an optional target table name

    • These methods allow you to easily retrieve an OleDbCommand, OleDbReader, or DataTable containing all the records in your target table of your datasource

    • If you don’t set DataSource here and it has not been set elsewhere, this method will fail

    • If you don’t set TargetTable here and it is an Access or Excel datasource and TargetTable is not set elsewhere, then “Sheet1″ or the first member of TablesList will be used for Excel or Access datasources respectively
      • 

    

  • CommandGetSql, ReaderGetSql, RecordsGetSql (sqlWhere as string, [fields] as string, [DataSource] as string, [TargetTable] as string)

      

    • All 3 methods take the same parameters:

        

      • Required: sqlWhere string, ex. “zipcode=’78258′ AND land_value>10000″

      • Optional: fields. A comma delimited list of fields to return with the query. ex. “owner_name, zipcode, land_value”

      • Optional: DataSource & TargetTable - see above for how the default values are handled for these 2 parameters
        • 

      

    • These methods allow you to easily retrieve an OleDbCommand, OleDbReader, or DataTable containing just the records in your target table of your datasource which meet your SQL criteria and optionally to return only the specified fields

    • If you want ALL the fields, pass Nothing or Void for fields. An empty string will cause an error.
      • 

    

  • SchemaTable

      

    • Returns a Schema DataTable for the DataSource not a TargetTable.

    • If you want a Schema DataTable for a table then get it from an OleDbReader on that table
      • 

    

  • FromXml, ToXml

      

    • Provides methods for serializing & de-serializing the object.

    • Since only DataSource is required for text & Dbase files and DataSource & TargetTable for Access and Excel, I don’t see these methods as being particularly useful. However, I always like to implement them just in case I need to persist an object or compare an object to a previous state.
      • 

    

    • 



Usage


Examples:


Get an OleDbReader for all records in an Excel file from a named sheet


dim jetdb as new JetDbConnect(”C:\myfiles\ExcelFile.xls”, “Hays County”)


dim reader as OleDbReader = jetdb.ReaderGetAll()


-or-


dim jetdb as new JetDbConnect


dim reader as OleDbReader = jetdb.ReaderGetAll(”C:\myfiles\ExcelFile.xls”, “Hays County”)


note: the class automatically adds the required decorations so that Hays County becomes [Hays County$] as required for SQL statements on an Excel datasource




Get a DataTable with select records & fields from delimited text file


dim jetdb as new JetDbConnect(”C:\myfiles\some text file.txt”)


dim dt as DataTable = jetdb.RecordsGetSql(”zipcode=’78258′ AND land_value>10000″,”owner_name, zipcode, land_value”)


note: I did not need to ever specify the TargetTable attribute since it is automatically set to “some text file.txt” and the Data Source is actually set to “C:\myfiles”




Get a list of available Sheets and Ranges from an Excel file without the need for any Office libaries or applications


dim jetdb as new JetDbConnect(”C:\myfiles\ExcelFile.xls”)


dim tables as List(of string) = jetdb.TablesList




Downloads


Just the DLL


The Visual Studio 2005 project


				

				
								
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				Categories : .NET Windows App,  General Programming,  Open Source,  VS 2005
						
			

				
		

			
						
			

				
				
Dev Summit Final Day

				
					24
					03
					2007
				
				
				

					
Day 3 Thurs Mar 22


I’m finally getting a chance to blog about this now. Steve, I, and nearly 2 dozen other attendees got totally screwed by the storms in Phoenix. However, at least we didn’t have to sit on the tarmack for nearly 3 hours like the other group waiting at the same gate. Though, by the time I got home 25 hours after leaveing the conference, sleeping in the Phoenix airport and eating only pretzals and snack mix; that wait seemed pretty trivial. I hope everyone else also eventually got home safely.


General Thoughts


This was a short day. Only 2 sessions and then the lunch & closing session. It seemed that about 25-30% of the folks had already left and a number of the ESRI devs had left as well. The sessions seemed a bit less technical that those on Wensday.


Sessions Attended


Building & Using ArcGIS Server Map Caches (Best Practices)


The MapCache is a tile cache created by rasterization & tile cutting of the data you have presented in your MXD. The main take home points of this talk were:


    

  • Understand what a tiling schema is 1st
    • 

  • Design your tiling schema BEFORE trying to build on for production use
    • 

  • Design a SINGLE schema that will serve the entire organization and all your data layers. In other words: Level 10 = the same scale for regardless of which layer you are building from; Tile sizes should be equal across various data sources; Use same origin point for all caches.
    • 

  • Client can rapidly reproject data to any projection system so use one that makes the most sense for both your data and web services methods (ideally, Geographic).
    • 

  • DO NOT use png24. PNG8 best if you need transparency, JPG best if you don’t need transparencey.
    • 

  • Smaller tile sizes (128×12 8) do not neccessarily result in faster performance over the web, while they take 5 times as long to produce & take up significantly more storage space than large ones (512×512). Test to make sure performance improvement is worth the extra effort. Use the largeest tiel size you can.
    • 

  • Fuse as many layers together as possible to create your base map caches. Therefore instead of Intermitten Streams, Permanent Streams, Rivers, & Lakes all being separate caches, they would be a single Hydrography cache that would appear as a single layer in the map service.
    • 

  • Each zoom level should be cartographically distinct
    • 

  • Forcing an ExportMapImage call from a web service can be a big performance hit. Understand what would make a client do that and avoid it as much as possible.
    • 

  • Building large many leveled caches can be VERY time consuming (days-weeks for worldwide layers). Pick a small area, TEST-TEST-TEST and then TEST before doing the full export, instead of having to do it over & over.
    • 

  • Cache will build over the extent of your MXD if the layer(s) you are building a cache for don’t have data in the full extent, background color tiles will be created. A waste of CPU time & storage space.
    • 

  • Dynamic cache building (a la TileCache) is planned for future releases.
    • 



Creating Windows & Web Apps with WPF


This was not at all about GIS. It was strictly on WPF.


WPF is very powerful & can provide you with a lot of UI design patterns.


Security & Permissions can be tightly controlled. Each app runs in a security sandbox. App origin, app settings, and client settings all interact to chose the most restrictive security level for the app.


You can do stuff with this technology TODAY. But, it’s real power won’t be realized until Visual Studio ORCAS is released and Vista or .Net 3 runtimes are more widely accepted. The 1 code for web & desktop paradigm is only for IE6+ with .Net 3 runtime right now. Must use WPF/E for other browser support.


Closing Session


Open Q&A after lunch. No really hard questions were asked, but Steve & other continued to point out that the extra cost of putting the ADF on a separate server is just not reasonable, and that the overall cost of ArcGIS Server is too high.


				

				
								
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				Categories : ArcGIS,  ArcGIS Server,  Developer Summit,  Web Mapping
						
			

				
		

			
						
			

				
				
Comparing Mashup Platforms Using JSON & MySQL - Part 1 - Emit JSON

				
					23
					03
					2007
				
				
				

					
Technologies Used: PHP 5, MySQL 4.1.2, JavaScript, JSON


Software Used: PHP Designer, Aptana, Firebug, Firefox


While I was not particularly impressed with the ArcWeb Explorer & ArcWeb Services session on Tuesday, it did inspire me to want to do a mashup using my own data sources. I also wanted to compare the mashup creation process & end results across multiple possible mashup platforms. I decided to use JSON since all the mashup API’s are in Javascript and it is an output format that both Google & Yahoo web services provide. I am already using JSON with the data entry interface for our Breeding Bird Census data that Plateau Land & Wildlife collects each spring.


JSON (or JavaScript Object Notation) is a well described data exchange format that is rapidly gaining favor over XML for web service data transport as it is less verbose and automatically parsed by Javascript.


While I had already created a JSON object model for use with our survey management system, it was structured in a totally different way than what I really wanted for my mashup. I also wanted to demonstrate doing this from scratch.


Step 1 - Design your JSON Object (i.e. Class Structure)


You want to put some thought into designing your class structure that you will emit. JSON can represent arrays, classes, and arrays of classes. The Good news is that JSON is VERY flexible, The Bad news is that JSON is VERY flexible. A general rule to follow in determining where you should use an array or class is that indexed lists = arrays, anything else is a class, or a class property (key:value pair). I just used the high tech method of pen & paper to design my JSON object, but you could also use any XML schema generation tool, VS2005 Class Designer, VIsio, etc.


My desired end product is a map showing the location & number of each point count station, with different symbols if it has been surveyed or not. A mouse over or click event will bring up an html table of with information about species observed and provide a Google search link for the bird based on it’s scientific name. The common name usually gets you all kinds of results whereas the scientific name gets you good reference results.


Thus I need Station number, lat/lon for the station, total observed, number of each species observed and scientific name for each species.


JSON Object


{"Observations":

[{"Station":

{"number":"9", "lat":"30.9999",

 "lon":"-98.9999","total_species":"9",

{"Species":

[{"common":"American Robin",

"number":"9", "code":"AMRO",

"scientific":"Turdus migratorius "},

{species cont....}

] } }

]

}





Or in other words:


Array Observations contains Station classes with Properties


    

  1. number

  2. lat

  3. lon

  4. total_species

  5. Array Species contains unnamed object with Properties

      

    1. common

    2. number

    3. code

    4. scientific
      5. 

    

    6. 



Step 2 - Create your JSON Object (i.e. Class Structure)


There are a whole bunch of ways to do this and really depends on what language your are programing in on your server side code. It basically boils down to either populating a class and then parse it to JSON through a method or class in your language, or directly writing the JSON string from some data source.


I chose the later for this project because my PHP install didn’t have a built in method for this. But rolling your own is pretty easy.


    

  1. Get results set from SQL query

    

    2. 



function getData($cid,$myYear,$func) { 


//cid = client id, myYear=year of survey, func=callback function to handle response


//Get a count of unique species occurring on the property for each point survey station, even those which have no recorded observations


$q_species=”SELECT DISTINCT st.sta_num as station, COUNT(species) as species, st.lat, st.lon


FROM Stations as st LEFT JOIN (Surveys as su) USING (station_id)


WHERE (st.client_id=$cid AND (su.client_id=$cid OR su.client_id IS NULL) AND su.year=$myYear)


GROUP BY station ORDER BY station;”;


  


//Get the details of species observed at each station


$q_obs=”SELECT su.species, su.number, sp.code, sp.scientific, st.sta_num as station


FROM Surveys as su, Species as sp, Stations as st 


WHERE su.client_id=$cid AND su.year=$myYear AND su.species=sp.common 


AND su.station_id=st.station_id 


ORDER BY station, sp.species_id”;


  


//Create the results sets                      


$resSpecies = mysql_query($q_species);


$resObs = mysql_query($q_obs);


  


2. Create the JSON String 


//Loop through each Station & create the JSON string for that Station & it’s data


$myJSON= $func.’({”Observations”:[';


While ($c=mysql_fetch_array($resSpecies)){


$myJSON.= '{"Station":{"number":"'.$c["station"].’”, “lat”:”‘.$c["lat"].’”, “lon”:”‘.$c["lon"].’”, “total_sp”:”‘.$c["species"].’”, “Species”:[';


                 While ($s=mysql_fetch_assoc($resObs)){


                                   if ($s["station"]==$c["station"]){


$observations.=’{”common”:”‘.$s["species"].’”, “number”:”‘.$s["number"].’”, “code”:”‘.$s["code"].’”, “scientific”:”‘.$s["scientific"].’”},’;


                                }


                }


                $myJSON.=rtrim($observations, ‘,’).’]}},’;


                $observations=”";


                mysql_data_seek($resObs,0);


 }


  


$myJSON=rtrim($myJSON, ‘, ‘).’]});’;


return $myJSON;


} 






Step 3 - Emit JSON


This is the easiest part of all. Just return the JSON string using whatever the response function is for the language you are using. PHP can use the HTTP Send Request / Get Response functions to give you more control & learn more about what is happening on either side of the exchanges. But, I kept it simple and just echo-ed the string.




echo getData($cid,$myYear,$func);




NEXT STEPS:


>Make & Handle request in your webpage/webapp


>Create mashup


				

				
								
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				Categories : Uncategorized
						
			

				
		

			
						
			

				
				
Dev Summit Continues

				
					22
					03
					2007
				
				
				

					
Day 2 , Wed Mar 21


I was really hanging this morning, for someone who has a beer or glass of wine only occasionally, going beer for beer with professional buisness travelers is never a good idea. But it was free and pretty decent beer so I can’t complain too much.


General Thoughts


I got a whole lot more out of today’s sessions and meetings than the 1st day. The talks I attended went into more depth, the .Net SIG was good, and I took Brian & James’s advice and spent more time talking with devs in the Community center.


A few interesting things I learned in these informal conversations


    

  • ArcGIS Explorer (AGX) will NOT have a custom skining option. You can mess around with some config files and the AGX document to change color themes, but that is about it. So a custom branded AGX that looked completely like your product but was actually AGX under the art, won’t be easily done.
    • 

  • AGX has no inherent editing capabilities, no area measurement tool and no way to discover any attributes about data sources other than local vector sources. You have to capture mouse events and do that work yourself.
    • 

  • AGX has no way of directly interperting ArcGIS geometeries, you must provide a map/globe service that is spitting out rasterized data or convert that geometery to E2 geometery yourself.
    • 

  • ArcWeb Services can add an ArcIMS service & soon an ArcGIS Server service to maps, but GeoRSS feeds, PostGIS, WMS, OGC, local/server stored vectors (shapefiles,PGDB, GDB, SDE, etc) all have to be progamatically adding in by transforming and adding the geometery to the map yourself. The only other way to get those alternate sources in is to intergrate them with ArcIMS or ArcGIS Server. If you do have a WMS you could but it through the OGC/ArcIMS translator servlet and leverage it that way.
    • 

  • A large number of people have compalined about the highly fragmented documentation, poor indexing, incomplete docs, and lack of community comments on EDN & other ESRI help sites. It may just be conference talk but it looks like at least a few people at ESRI are begining to listen. Time will tell.
    • 



Sessions Attended


    

  • Programing Custom Tasks for ArcGIS Explorer
    • 

      

    • The task framework is not direct & intuitive. RTFM on that or you will really be lost. Not directly supported formats such as GeoRSS are not terribly difficult to transform into E2 geometeries and create content from a vast array of data sources. Just don’t expect AGX to do that for you. Deploying custom tasks is SUPER easy. Deploying a malicous task is also possible so watch what you download. They are looking for ways to patch that which won’t create Admin required installs. AGX2 is in the works and the more feedback you give them on the forums and directly, the better it will be.
      • 

    

  • Special Interest Group: .Net
    • 

      

    • A brief marketing talk about MS Visual Studio Team Foundation Server was followed up by Dave Bouwman’s great talk about wrapping feature classes, SDE, & GDB in .Net abstractions using well known code gen techinques from non-spatial DB. It pulled together some of his posts on the subject and made it all look like such a better way to code. I’ve actually used the same techinques on shapefiles using RapTier and either the Jet OleDb or the ESRI OleDb drivers. Shapefiles are not as ammenable to being edited in this manner as PGDB or other real database storage formats are. I can read the data very well and databind on it but updating the gives rather unpredictable results.
      • 

    • I would strongly recommend visiting Dave’s blog and checking out his talk and an resources it is an exicting concept. It also makes you wonder, why they don’t just offer Dave a position or short-term contract at ESRI to incorporate all they modern coding techniques in at least ArcGIS 10 if not 9.3. When you see simple object property assignments rather than the AO way of doing it and the self policing code it creates, you wonder why in the world would you want to do it the old way.
      • 

    • James Fee hit on the craziness that is the 9.2 server licensing & the unreasonable expectation to pay 1/2 of the 1st license cost (of ~20k at retail) to put the Web ADF on another machine. He was told, “We know people don’t like it, but that is the business model for today. We may be changing it in future releases but don’t hold your breath” (paraphrasing, not a direct quote).
      • 

    

  • Building & Deploying Enterprise Solutions with ArcGIS Server
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    • Not a lot of good tech meat here, just an eye opening talk about all the hoops & roadblocks that deploying ESRI server products in lerge organizations that don’t conform to ESRI’s way of doing things can cause.
      • 

    

  • Developing Custom Web Tasks using the .NET Web ADF
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    • A lot of technical meat in this session. It went a long way to demonstrate that doing interesting things using this framework is not going to be so easy. You really have to jump through a lot of hoops to make cool things happen, and you have to jump through too many hoops to make super simple things happen. They covered a lot of techniques, tips, & tricks for working with this and I highly recomend veiwing this session on the post-conference web site if available. Especially the code that way demonstrated at the last 3rd of the talk.
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  • ArcGIS Mobile SDK
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    • A super energetic talk was presented by Jeff & Mike. They have really worked hard to abstract all the underlying native C++ code into a 1st class .NET SDK. They have built a really nice toolkit for VisStudio & using it and the Mobile 5 libaries, you can get some nice applictions working with a very minimal amount of code. It relies heavily on MapCaches produced by ArcGIS Server and they didn’t go into creating those or pushing them out but I’m hoping to get that info in a later session. This was my favorite talk by ESRI thus far.
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				Comments : 1 Comment »
				

				
				

				Categories : .NET Windows App,  AGX,  AWX,  ArcGIS,  ArcGIS Explorer,  ArcGIS Server,  ArcWeb Mapping,  Developer Summit,  VS 2005
						
			

				
		

			
						
			

				
				
Thoughts on Dev Summit

				
					22
					03
					2007
				
				
				

					
Day 1 (for me) Tues, Mar 20


Due to airline maintance problems, I didn’t get to the Summit until after the Plenary session was over. So I can’t comment on that although several others can.


Rob Elkins - 1, 2, 4, 5

Dave Bouwman

The Steve0


General Thoughts


I was deeply disapointed with the 1st day of Tech Sessions that I attended. I figured that the Best Practices sessions would be general overviews, but the Deep Dives I attended weren’t very deep. This was probably made worse by the fact that they couldn’t get internet connections to work during the presentations. I should have followed James & Brian’s advice to just hang out in the Community Center and listen to Tech Talks and speak with the ESRI Devs themselves. The highlight of that day was getting to meet somany of the other geo bloggers and members of the ESRI team whose names I knew but had never seen or spoken to before.


Sessions Attended


Leveraging ArcWeb Services in GIS (Best Practices)


This was a nearly utter waste of time. They basically just walked through the docs, info & help from ArcWeb Services home page. This site is in fact far more informative than the talk was. The only truly interesting bit of info from this is that AWX v2 will be coming out later in the year. It is currently in alpha right now. This will allow direct connection to ArcGIS Server and possibly OGC web services.


Building AJAX-Based Web Apps with Server & .Net (Deep Dive)


Slight snorkel would have been appropiate. Again, you could learn as much and more from the SDK docs. The main take home message from this was that the out-of-the-box toolkit and base classes have ICallbackEvent handlers pre-cooked into them. Thus you don’t have to directly handle implementing the request & response callback functions in JavaScript. You just pass and recieve delimited text serializations. They delimited text was 30-40% faster than XML. JSON adds another 12-15% and will be directly supported soon (probably 9.3).


Deploying & Tuning ArcGIS Server / Leveraging GeoProces Framework in ArcGIS Engine .Net


The Server deployment was well attended and was also the subject of several very in depth Tech Talks. Grumblings about the licensing model and its pricing structure that actually discourges implementing the best practices models continue.


I caught the last half of the GP in Engine talk. That was rather interesting. Some compliants have been made about sending big tasks off to the GP only to have them fail or crash the coputer with no ryhme or reason. Appearently you can implement a listner that will talk to you about the status of your job as it is processing. That technique is not easily discoered through help docs.


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				Comments : 3 Comments »
				

				
				

				Categories : AWX,  ArcGIS,  ArcGIS Server,  Developer Summit