Hi,

in the link that you posted, GeoServer is being used to transfer the data from the PostGIS database to the html map with the openlayers library.

Are you using GeoServer or some other middleware to pull the data from the PostGIS database? I believe that a direct link between a database and an html page is not possible.

I am asking because in the example the settings of GeoServer are not posted, which is a rather tedious procedure, but basically you need to setup a layer link from data of the PostGIS database and then use this link to pull the wms (or some other type) layer to the html.

GP

Thanks for your response sir,

I am using geoserver as middleware to pull the PostGIS database using open layer. Actually I publish the PostGIS data to geoserver for WMS and WFS services.

Thanks

Alright then,

I guess the problem must be in the html-javascript side. You can try a few thing to see if the layer is getting pulled from the geoserver. In javascript you can use the command:

console.log();

to log stuff in the console. For instance you can try:

console.log(result);

after you add the map layer to check if the layer is coming correctly from the geoserver. Also check if the openlayers library is loading correctly.

The ol.js file should be in a directory named ol3 where your html file is.

PS: to see the console in a browser right click on the screen -> view source -> console.

Thanks for your answer sir,

Actually, I do all the instruction which you mentioned in previous answer. Still now I am not getting the result. I didn't get any error in console panel of page source. Also on browser I am getting only OSM map and two marker but not of my area of interest. 

Sir, I have a basic question that is, The tutorials I read or paper I refereed for this implementation all are using OSM map for shortest route but in my condition I am not using OSM data. Actually the data I am using is a vector layer created using georeferncing in QGIS and store in PostGIS database. 

So. My question is that, is it possible to do pgrouting application on our own layer created in QGIS rather than OSM data?  If  it is possible then what's going wrong in my code. The code is written as follows:

ol3 pgRouting client

clear

Hello again,

First of all, the OSM map has nothing to do with the vector layers that you add on the map. It is just a background map layer which most people use. This is added in these lines:

layers : [new ol.layer.Tile({

    source : new ol.source.OSM()

})],

Also, after that, an initial center and zoom is set:

view : new ol.View({

                center : [74.60139, 16.84438],

                zoom : 10

}),

Now, in this example, it is supposed to provide a route between two points that a user clicks on the map. After that a query runs on the geoserver and the result is projected to the map as a wms layer. I understand this is not what you want to achieve.

Notice that in your code you add the layer inside a map click event:

map.on('click', function(event) {

                ……

});

That means that whatever happens the layer will be added to the map after you click on the map. In addition, the layer is specifically added after the second click. Watch the if statement:

if (startPoint.getGeometry() == null) {

                ….

} else if (destPoint.getGeometry() == null) {

                … (here is the second click!)

}

Finally, the layer gets some parameters from the points clicked:

var viewparams = [

      'x1:' + startCoord[0], 'y1:' + startCoord[1],

      'x2:' + destCoord[0], 'y2:' + destCoord[1]

];

params.viewparams = viewparams.join(';');

in order to run the query in the geoserver.

Well, you don’t need all that. Actually, if you just want to add a wms layer from a geoserver you need something like in this example:

http://openlayers.org/en/latest/examples/wms-image.html?q=geoserver

Just delete the line ‘extent: ….’ In the layer properties and replace the url with your local geoserver:

url: 'http://localhost:8080/geoserver/wms',

and the layer parameters:

params: {'LAYERS': 'workspace:layer'},

where you should put your workspace and corresponding layer.

Try that and see if you get any errors or result.

G

http://openlayers.org/en/latest/examples/wms-image.html?q=geoserver

Thanks sir,

The suggestion that you give me in your answer is all about adding wms layer of geoserver to our code.

But, Actually I want to implement the routing application using postgis, geoserver and open layer. It is supposed to provide a route between two points that a user clicks on the map. After that a query runs on the geoserver and the result is projected to the map as a wms layer. That I want to do but not achieve. Can you give me some reference code to do the routing.

Ok sorry, my mistake, I thought you just needed to present the results of some queries to the html map.

It is possible to run pgrouting with your own data, and as you said it works fine in geoserver when you run the queries. So lets check if the data that are send to the geoserver are working.

You can put a console log to check the viewparams.

console.log(viewparams);

or maybe even on params console.log(params);

just before the creation of the result layer. Then see if the parameters work in the SQL statement of the pgrouting view in the GeoServer. Just run the SQL query with the coordinates that you got from the console log. If that works fine then something is wrong with the connection between the javascript and GeoServer. If the SQL query doesn't work then something must be wrong with the network.

Alternatively, you can try something else. Try to send to the geoserver coordinates that you know that work (from the queries that you run and worked) to see if the layer is projected. To do that change the viewparams to your known coordinates:

var viewparams = [

      'x1:' + 'put your coords in here', 'y1:' + 'put your coords in here',

      'x2:' + 'put your coords in here', 'y2:' + 'put your coords in here'

];

Actually When I run console.log(viewparams) then I got the error VM72:1 Uncaught ReferenceError: viewparams is not defined(…) How should I remove.

Strange.

Check the variable spelling and make sure that you call the console log inside the second click event, because that is when the viewparams variable is created. Put it after this line:

params.viewparams = viewparams.join(';');

and better yet do a console log for params since this is what will be send to the GeoServer anyway.

Hi George Panagiotopoulos,I encountered the same problem, But for me, i checked and the data that are send to the geoserver work very well. Even the result is returned but nothing is displayed.

Thank you in advance

But if I remove this statement : params.viewparams = viewparams.join(';'); the default route appears.

the default route is the route with defaults coordinates that I set in geoserver.

Dear Imrane,

from what I saw in your code, the queries that you are executing in postgis are in different projection systems.

This:

SELECT * from pgr_route_entreAEtB('rtss_rvq',707638.180795492,322271.843950542,688187.240281371,321124.722855781)

I am guessing is in EPGS:3857 and this:

SELECT * from pgr_route_entreAEtB('rtss_rvq',-71.4670944213867,46.877794945067336,-71.21646881103514,46.89046619925003)

is probably in EPSG:4326

If your data in postGIS are in EPSG:3857 then it seems to me that you don't need to use the transform function in your code.

Try removing it and see what happens. Also, try to transform those coordinates manually in some online converter to EPSG:3857 and run the query with those values.

Let me know how it goes!

Hi Mr. George Panagiotopoulos, thank you a lot for your response,

I tried your recommandation. My projection system in postGIS is EPSG:3798

I have converted  pgr_route_entreAEtB('rtss_rvq',-71.4670944213867,46.877794945067336,-71.21646881103514,46.89046619925003) from EPSG:4326 to

SELECT * from pgr_route_entreAEtB('rtss_rvq',688217.473645,321057.385222,707333.896521,322132.865222)  in EPSG:3798 (my postGIS data format) but I obtained the follow error:

ERREUR: Target vertex was not found.

État SQL :XX000

Contexte : fonction PL/pgsql pgr_route_entreaetb(character varying,double precision,double precision,double precision,double precision), ligne 53 à FOR sur une instruction EXECUTE

And I set the coordinates in the following way: 

var viewparams = [

'x1:' + '707638.180795492', 'y1:' + '322271.843950542',

'x2:' + '688187.240281371', 'y2:' + '321124.722855781'

];  these coordinates work well in the postGIS request

in browser's console i have 

command: console.log(params);

Object

FORMAT:"image/png"

LAYERS:"gestR:rs_R_V"

viewparams :

"x1:707638.180795492;y1:322271.843950542;x2:688187.240281371;y2:321124.722855781"

__proto__

:Object

command: console.log(result):

vk

Ga:false

T:Object

closure_uid_359341927:3954

g:1

j:null

l:null

o:Object

olm_5985:Object

ta:Object

ua:undefined

__proto__:Fi

but nothing showing on the map