Robert the Mapper's Super Blog

..or Government use.. oh..

2008-08-29T20:58:00.000-07:00

Sadly, my awesome precinct mashup was put on hold for several weeks. I had been happy with how the map was turning out and thought about putting it more prominatly somewhere on the County website. I didn't think much about it until I accidentally came across a reference to the Terms of Use on a forum post.

(ii) Commercial or Government use: If you would like to develop or host an Application that is designed to access and use the service for commercial or government use, you must enter into a separate MWS/VE agreement.

oops.. I swapped a few e-mail with Microsoft and verified that the County would need to buy some sort of licence to use the API. Since the county is already heavily invested in ERSI's products a VE licence was not an option. Crap..

This project started as a personal project and so it shall be again! I've set up a site to host the project and am in the process of moving it over. Now the site should fall under the free non-commercial use. I think..?

(i) Non-commercial use:
Right to use: Subject to your compliance with this agreement, you may develop or host an online application (an “Application”) that is designed to access and use the service to display results for non-commercial use, using only methods and means of access that are documented in the SDKs described at the end of this agreement (“SDKs”). Your Application and content in your Application must be available publicly without restriction (for example, login or password must not be required). We may require access credentials to use the service, and may require use of transaction tracking methods for some or all uses of the service, as described in the SDK.

The site's new location will be at www.robertthemapper.com .

Precinct Mashup Part 2 - Exporting to Georss.xml

2008-08-04T21:20:00.000-07:00

I finally got a semi-working version up here. You may need to refresh the page. For some reason the initial load is bombing out somewhere. I haven't looked into it yet.

My first attempt at creating a geoRSS.xml file for Virtual Earth only involved a handful of points so it didn’t take too long to write the file with XML Notepad. My precinct project uses over 100 features, half of which are complex polygons. I needed to automate the xml file creation, but I didn't find many helpful tools online for doing this. Even if I did find a tool (ArcGIS 9.3 has a KML export tool), it probably wouldn't be flexible enough.

The cool thing about using xml files to view custom data is that you can fill the tags with html to use for mouse events. For example, the <decription> tag holds the HTML that fills the mouseover pop-up for my poll site pushpins and the about box for the selected precinct. The HTML for the description tag is built using field values from the ArcGIS feature class I created. For each feature I added field values for a picture, atl image text, poll address, precinct name and a pdf file name.

My precinct polygons and poll site points files follow the following format:

<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0" xmlns:georss="http://www.georss.org/georss" xmlns:gml="http://www.opengis.net/gml" xmlns:Cml2GeoRssHelper="urn:Cml2GeoRssHelper">
<channel>
<title>file title</title>
<description />
<item>
<title>title text</title>
<description>description text and HTML</description>
<georss:point>lat, long (decimal degrees)</georss:point>
</item>
</channel>
</rss>

The xml is created in ArcMap by looping though each feature and writing them to a text file. Here's the VBA I used to create my precinct polygon file. It's nothing special; I'm a mapper not a programmer!

Set pMxApp = Application
Set pMxDoc = Application.Document
Set pMap = pMxDoc.FocusMap
Set pfeaturelayer = pMap.Layer(0)
Set pfeaturecursor = pfeaturelayer.featureclass.Search(Nothing, False)
Set pfeature = pfeaturecursor.NextFeature
coords = ""

Dim pFileSystem As Object
Dim pFile As Object
Dim ppointcollection As IPointCollection

Set pFileSystem = CreateObject("Scripting.FileSystemObject")
Set pFile = pFileSystem.CreateTextFile("G:\gisusers\Robert\CODE WORK\VE_PROJECTS\VOTER\precincts.xml", True)


pFile.WriteLine "<?xml version=""1.0"" encoding=""utf-8""?>"
pFile.WriteLine "<rss version=""2.0"" xmlns:georss=""http://www.georss.org/georss"" xmlns:gml=""http://www.opengis.net/gml"" xmlns:Cml2GeoRssHelper=""urn:Cml2GeoRssHelper"">"
pFile.WriteLine "  <channel>"
pFile.WriteLine "    <title>BERKELEY COUNTY PRECINCTS</title>"
pFile.WriteLine "    <description />"

Do While Not pfeature Is Nothing
'check if feature is a polygon
If pfeature.Shape.GeometryType = esriGeometryPolygon Then
   Set pPolygon = pfeature.Shape 'get the polygon
   Set ppointcollection = pPolygon 'get its vertices
   For I = 0 To ppointcollection.PointCount - 1 'loop thru all vertices
       'create new point of the vertice
       Set pnt = ppointcollection.Point(I)
       coords = coords & " " & pnt.Y & " " & pnt.X

   Next I

TITLE = pfeature.Value(3)
NAME = pfeature.Value(9)
POLL = pfeature.Value(10)
ADDRESS = pfeature.Value(11)
IMAGE = pfeature.Value(14)
MAP = pfeature.Value(16)
IMAGE_ALT = pfeature.Value(15)

pFile.WriteLine "    <item>"
pFile.WriteLine "      <title PRECINCT = """ & UCase(POLL) & """>" & pfeature.Value(3) & "</title>"
pFile.WriteLine " <description>&lt;table width=""170"" border=""0"" cellspacing=""2"" cellpadding=""0""&gt;&lt;tr&gt;&lt;td&gt;&lt;span class = ""info_precinct""&gt;" & TITLE & "&lt;/span&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;Poll Site:&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;img src=""images/red_dot_icon.png"" align=""absmiddle"" border=""0"" /&gt;  &lt;span class = ""infopoll"" &gt;" & POLL & "&lt;/span&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;span class = ""infoaddr""&gt;" & ADDRESS & "&lt;/span&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;img width=""165"" src=" & IMAGE & " alt="" "" align=""top""/&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;span class=""link"" onclick=""javascript:zoomtopoll('" & POLL & "');""&gt;Zoom to Street Level&lt;/span&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;a href=""" & MAP & """&gt;Download Precinct Map&lt;/a&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;"
pFile.WriteLine "  </description>"
pFile.WriteLine "      <georss:polygon>" & coords & "</georss:polygon>"
pFile.WriteLine "    </item>"
coords = ""
End If
Set pfeature = pfeaturecursor.NextFeature
Loop

pFile.WriteLine "  </channel>"
pFile.WriteLine "</rss>"
pFile.Close

The result looks like this. One thing to remember when filling the xml tags with HTML is that you will need to convert < and > to > and < .

The final xml files can be loading into virtual earth using the: VEMap.ImportShapeLayerData Method

Precinct Mashup Part 1

2008-08-01T20:15:00.000-07:00

This is my second Virtual Earth "mashup" project. I had some success with my first project but never properly finished it. Too much work and too little time for a small audience (unlike my blog).

I've been excited by the possibilities of the Virtual Earth API and wanted to come up with a project that would fulfill a mapping need not covered by our IMS site. After some recent map requests, I decided voting precincts and poll locations would be a nice and simple project that would be useful to a potentially large audience.

The county IMS site doesn't include precincts; they would just be lost in the collection of other layers that never get noticed or turned on. There's still a large chunk of users that just don't get the concept of turning on and off layers in the table of contents. IMS is also slow as hell and boring.

Mashup projects seem to really shine when they are focused and simple.

Here's a small list of features I had in mind:

precinct polygons
poll location points with pictures
links to pdf precinct maps
address search tool
precinct search list
links to other voting resources
sexy web 2.0 flash

The first step was getting the voting data into Virtual Earth compatable georss xml files. I ended up writing some VBA code to translate the ArcGIS feature classes into xml. That sounds impressive! It will be the topic of my next post. woooo