Get the leaflet map working with CAs

[hxu]

Partially implemented in MapCtrl

[2blam]

I asked Land Survey students to get some idea about the coordinate system. I used another approach to generate the geojson. Please check https://github.com/2blam/HK-geojson The map can show constituency area in Hong Kong. When the mouse clicked on the polygon, it shows the corresponding CA names. @vincentlaucy see if it can help and put it to frontend

[debuggingfuture]

Thanks @2blam,

Example for ref:
http://tombatossals.github.io/angular-leaflet-directive/examples/geojson-example.html

Ideally IMO we can reuse the same map, when click to DC we increase zoom
level and polygons are drawn to geojson of CA inside. zoom out to draw DC
again.
which is more dynamic than
http://www.census2011.gov.hk/en/constituency-area-cnw.html

On Tue, Jan 28, 2014 at 7:01 PM, 2blam notifications@github.com wrote:

I asked Land Survey students to get some idea about the coordinate system.
I used another approach to generate the geojson. Please check
https://github.com/2blam/HK-geojson The map can show constituency area in
Hong Kong. When the mouse clicked on the polygon, it shows the
corresponding CA names. @vincentlaucy https://github.com/vincentlaucysee if it can help and put it to frontend

Reply to this email directly or view it on GitHubhttps://github.com//issues/10#issuecomment-33468766
.

[hxu]

Sounds like a good strategy to me. So to summarize:

• Draw DC on map, lightly colored, so that you can see the underlying map. Hover highlights it
• Clicking on a DC zooms in and draws CAs. lightly colored, and hover highlights the shapes

However, once zoomed into the CA, I would say that you need at least one links next to the map: a Zoom out or Back link to return to the DC view.

The other link may be to Select all, if you wanted to select more than one CA, but it would actually be better if you could do this without zooming into the CA view at all.

Also, I think any implementation should allow toggling of selecting more than one CA. In some cases, we only want to be able to select one CA. In other cases, we may want to select more than one.

[hxu]

@vincentlaucy are you working on the maps tonight? If not, I will take a look at it in a bit.

[debuggingfuture]

Not working at it at the moment. Can see anything to help on sun
Am 31.01.2014 19:25 schrieb "hxu" notifications@github.com:

@vincentlaucy https://github.com/vincentlaucy are you working on the
maps tonight? If not, I will take a look at it in a bit.

Reply to this email directly or view it on GitHubhttps://github.com//issues/10#issuecomment-33786784
.

[hxu]

OK, no worries, it's a holiday, people should be with their families :-).

Just thinking out loud as I work through this: Taking a look at the geojson files, it looks like we still need to do a few things:

• GeoJSON objects for district councils and constituency areas need their unique identifiers in their features hashes.
• Can probably strip the rest of the properties from the features hash, though at some point it may be useful to have the area and perimeters of each area.
• GeoJSON files need to be smaller -- Constituency Areas file is currently 4MB. Should run it through TopoJSON

Next, to implement the actual interface, I will make a directive for the map. Going to plan it out with a spec and tests first, but it should probably implement the following features:

• Click to select individual CAs
• Ability to select all CAs within a district at once
• Show CAs or Districts based on zoom? Not sure about this one yet
• Different styling for selected vs. non-selected CAs
• Needs two way binding outside of directive, so that other objects can detect which CAs are selected.

[debuggingfuture]

@2blam did a simplification inside qgis and got a smaller geojson
https://github.com/2blam/HK-geojson
Am 31.01.2014 20:51 schrieb "hxu" notifications@github.com:

OK, no worries, it's a holiday, people should be with their families :-).

Just thinking out loud as I work through this: Taking a look at the
geojson files, it looks like we still need to do a few things:

• GeoJSON objects for district councils and constituency areas need
  their unique identifiers in their features hashes.
• Can probably strip the rest of the properties from the featureshash, though at some point it may be useful to have the area and perimeters
  of each area.
• GeoJSON files need to be smaller -- Constituency Areas file is
  currently 4MB. Should run it through TopoJSONhttp://bost.ocks.org/mike/simplify/

Next, to implement the actual interface, I will make a directive for the
map. Going to plan it out with a spec and tests first, but it should
probably implement the following features:

• Click to select individual CAs
• Ability to select all CAs within a district at once
• Show CAs or Districts based on zoom? Not sure about this one yet
• Different styling for selected vs. non-selected CAs
• Needs two way binding outside of directive, so that other objects
  can detect which CAs are selected.

Reply to this email directly or view it on GitHubhttps://github.com//issues/10#issuecomment-33791447
.

[hxu]

Ah okay, I remember now. Thanks for reminding me.

On Fri, Jan 31, 2014 at 8:59 PM, vincentlaucy notifications@github.comwrote:

@2blam did a simplification inside qgis and got a smaller geojson
https://github.com/2blam/HK-geojson
Am 31.01.2014 20:51 schrieb "hxu" notifications@github.com:

OK, no worries, it's a holiday, people should be with their families :-).

Just thinking out loud as I work through this: Taking a look at the
geojson files, it looks like we still need to do a few things:

• GeoJSON objects for district councils and constituency areas need
  their unique identifiers in their features hashes.
• Can probably strip the rest of the properties from the featureshash,
  though at some point it may be useful to have the area and perimeters
  of each area.
• GeoJSON files need to be smaller -- Constituency Areas file is
  currently 4MB. Should run it through TopoJSON<
  http://bost.ocks.org/mike/simplify/>

Next, to implement the actual interface, I will make a directive for the
map. Going to plan it out with a spec and tests first, but it should
probably implement the following features:

• Click to select individual CAs
• Ability to select all CAs within a district at once
• Show CAs or Districts based on zoom? Not sure about this one yet
• Different styling for selected vs. non-selected CAs
• Needs two way binding outside of directive, so that other objects
  can detect which CAs are selected.

Reply to this email directly or view it on GitHub<
https://github.com/hxu/hk_census_explorer/issues/10#issuecomment-33791447>

.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/10#issuecomment-33791842
.

[hxu]

Fixed by pull request