{"id":5223,"date":"2018-05-10T20:40:15","date_gmt":"2018-05-10T18:40:15","guid":{"rendered":"http:\/\/www.sigterritoires.fr\/?p=5223"},"modified":"2018-10-17T12:10:48","modified_gmt":"2018-10-17T10:10:48","slug":"qgis-and-web-an-update","status":"publish","type":"post","link":"https:\/\/www.sigterritoires.fr\/index.php\/en\/qgis-and-web-an-update\/","title":{"rendered":"QGis and WEB: an update"},"content":{"rendered":"

The WEB\u00a0is no\u00a0longer\u00a0reserved\u00a0for large\u00a0accounts.\u00a0The\u00a0technical\u00a0means\u00a0and the\u00a0costs\u00a0of the solutions\u00a0are\u00a0no\u00a0longer an obstacle for\u00a0everyone\u00a0to\u00a0publish on the WEB\u00a0their\u00a0data\u00a0and\u00a0maps.\u00a0 But this development has gone hand in hand with a multiplication of technical solutions and the main obstacle, today, is to choose the best solution to one\u2019s needs. We will discuss here a rather general overview, but which, I hope, will help you to make a suitable choice.<\/p>\n

Maps<\/strong>\u00a0and \/<\/strong>\u00a0or<\/strong>\u00a0data<\/strong>?<\/p>\n

The first question is, always, WHAT? What do you want to publish? You can stream maps, ie the equivalent of what you see in your QGis interface on the computer. The user retrieves the URL of your map and he finds a simplified GIS interface and a map formatted by you. He can zoom, display or cancel the different layers but he does not have direct access to your data. You publish the result of your work, not the means you have used.<\/p>\n

You can, also, choose to put on line your data, i.e. to render accessible data layers, without any special format. In this case, the user will perform a WFS or WMS connection to your data and he will be able to integrate it into his own projects by coupling it with his own data.<\/p>\n

According to\u00a0the\u00a0tools\u00a0selected,\u00a0you\u00a0can\u00a0do\u00a0either\u00a0one or\u00a0both.<\/p>\n

Quantity?<\/strong><\/p>\n

The\u00a0second\u00a0question\u00a0is\u00a0HOW MANY?\u00a0Without trying to\u00a0predict the exact megaoctet,\u00a0you\u00a0need to\u00a0know in\u00a0advance whether\u00a0you\u00a0want\u00a0to share\u00a0your raster\u00a0data\u00a0or\u00a0not.\u00a0If\u00a0you\u00a0restrict yourself to the vector data, then\u00a0your data\u00a0volumes\u00a0will,\u00a0in\u00a0principle,be\u00a0well\u00a0below the limits of the proposed tools.\u00a0\u00a0On the other side,\u00a0if\u00a0you\u00a0work\u00a0with\u00a0raster\u00a0data\u00a0(images,\u00a0mnt\u00a0, etc)\u00a0you\u00a0will exceed\u00a0these\u00a0limits from\u00a0the very beginning.<\/p>\n

Investment<\/strong>?<\/p>\n

The\u00a0cost\u00a0of the\u00a0chosen\u00a0solution\u00a0is not\u00a0limited\u00a0to\u00a0the software\u00a0or hosting costs.\u00a0The\u00a0main\u00a0cost\u00a0will be\u00a0your\u00a0time.\u00a0Let\u2019s\u00a0assume that\u00a0you\u00a0already\u00a0know\u00a0QGis.\u00a0You\u00a0have already solve where to put on\u00a0line\u00a0your\u00a0maps\u00a0and \/\u00a0or\u00a0data\u00a0by using a plugin in\u00a0QGis\u00a0.\u00a0You\u00a0will, also, have other solutions that imply an investment in time and effort to learn how to use other software.\u00a0 Some\u00a0solutions will\u00a0work\u00a0on\u00a0your computer,\u00a0others will\u00a0require to install\u00a0a\u00a0Web\u00a0server.\u00a0If\u00a0your\u00a0world is\u00a0limited\u00a0to Windows,\u00a0you\u00a0are\u00a0likely\u00a0to have\u00a0to use Linux.<\/p>\n

So try\u00a0to\u00a0stay\u00a0as\u00a0close\u00a0as possible to\u00a0your\u00a0needs.<\/p>\n

Putting your data<\/strong>\u00a0on<\/strong>\u00a0line.<\/strong><\/p>\n

Putting your geographic data on line is performed through\u00a0the so called\u00a0WFS\u00a0or\u00a0WMS\u00a0streams.\u00a0These\u00a0two strange\u00a0terms\u00a0simply\u00a0refer\u00a0to\u00a0two\u00a0standard\u00a0data\u00a0exchange\u00a0protocols.\u00a0The first, WFS, is the\u00a0vector data?\u00a0The\u00a0second,\u00a0WMS refers to\u00a0raster\u00a0data\u00a0\u00a0but\u00a0also\u00a0to the vector data\u00a0vector\u00a0displayed as\u00a0images\u00a0(\u00a0similar to \u00a0sending\u00a0a\u00a0copy of your vector layers by using a screen shot).<\/p>\n

\"\"<\/p>\n

 <\/p>\n

Geoserver<\/strong><\/p>\n

All\u00a0the solutions\u00a0regarding\u00a0QGis\u00a0that we\u00a0will address here\u00a0allow\u00a0to\u00a0make your WMS and WFS fluxes of your data available to the WEB.\u00a0But\u00a0if\u00a0you\u00a0have\u00a0a\u00a0WEB\u00a0server\u00a0the\u00a0best\u00a0solution\u00a0is\u00a0to\u00a0put\u00a0in\u00a0place Geoserver.\u00a0This is an Open Source\u00a0software,\u00a0free, powerful and very,\u00a0it\u00a0will be a good\u00a0investment.\u00a0For\u00a0basic\u00a0use,\u00a0you\u00a0won\u2019t\u00a0need\u00a0more\u00a0than one\u00a0day\u00a0to\u00a0install, configure and start\u00a0putting\u00a0in\u00a0place\u00a0your\u00a0data\u00a0feeds.<\/p>\n

You\u00a0can\u00a0to put\u00a0on\u00a0line shapefile<\/a> layers\u00a0but\u00a0if\u00a0you\u00a0truly want\u00a0to\u00a0harness\u00a0the\u00a0power of\u00a0Geoserver\u00a0it is advisable to couple it with PostgreSQL \/\u00a0Postgis<\/a>\u00a0.<\/p>\n

For\u00a0more\u00a0information\u00a0on\u00a0this\u00a0solution, I\u00a0invite\u00a0you\u00a0to read\u00a0the article\u00a0\u00a0\u00a0\u00ab\u00a0<\/a>\u00a0\u00a0<\/a>\u00a0Start\u00a0with\u00a0Geoserver<\/a>\u00a0\u00a0<\/a>\u00a0\u00ab\u00a0<\/a>\u00a0.<\/p>\n

Putting<\/strong>\u00a0on<\/strong>\u00a0line<\/strong>\u00a0your<\/strong>\u00a0maps<\/strong>\u00a0and<\/strong>\u00a0\u00a0data<\/strong><\/p>\n

QGis<\/strong>\u00a0Cloud<\/strong><\/p>\n

\"\"<\/p>\n

 <\/p>\n

QGis\u00a0Cloud\u00a0is\u00a0a\u00a0QGis\u00a0plugin\u00a0associated\u00a0with a cloud service.\u00a0The plugin allows\u00a0you\u00a0to\u00a0load\u00a0your QGis\u00a0project\u00a0in the cloud, load\u00a0your\u00a0data\u00a0on\u00a0a\u00a0cloud basis and\u00a0to get\u00a0in\u00a0return\u00a0a\u00a0URL which\u00a0allows\u00a0you to visualize\u00a0your\u00a0map with\u00a0a\u00a0simplified\u00a0interface GIS\u00a0and\u00a0a\u00a0URL to\u00a0access\u00a0the WMS feed of\u00a0your\u00a0data.\u00a0Therefore the map\u00a0is\u00a0\u00a0accessible with a simple\u00a0WEB\u00a0browser\u00a0and, by\u00a0default\u00a0, the public\u00a0can\u00a0connect to the Cloud WMS stream to\u00a0integrate\u00a0your\u00a0data\u00a0in\u00a0their\u00a0own\u00a0projects\u00a0.<\/p>\n

With\u00a0some very simple\u00a0adjustments,\u00a0you\u00a0can put\u00a0on\u00a0line\u00a0your\u00a0 vector\u00a0layers\u00a0(WFS) and,\u00a0even,\u00a0allow\u00a0users\u00a0to\u00a0update\u00a0the\u00a0data\u00a0(WFS-T).<\/p>\n

You\u00a0do not have\u00a0to\u00a0take care\u00a0of server\u00a0side by adopting this\u00a0solution.\u00a0QGis\u00a0Cloud\u00a0manages the\u00a0databases\u00a0and\u00a0online setting\u00a0tools\u00a0of the map.<\/p>\n

So much for now.\u00a0Now,\u00a0what\u00a0are\u00a0the disadvantages\u00a0of\u00a0this\u00a0option?\u00a0First\u00a0of all\u00a0the\u00a0data\u00a0volumes.\u00a0If you are using the free option, your project cannot exceed 50MB.Therefore you cannot include raster layers in your project. This\u00a0does\u00a0not\u00a0apply\u00a0to a raster\u00a0base map\u00a0like\u00a0Goggle Satellite, OSM, Bing, etc. because\u00a0QGis\u00a0Cloud\u00a0allows you\u00a0to\u00a0define\u00a0one\u00a0of\u00a0these\u00a0sources\u00a0as a\u00a0base map\u00a0excluding its data volume (the\u00a0map is\u00a0not\u00a0loaded\u00a0into\u00a0your\u00a0database).<\/p>\n

Nevertheless you can upgrade to\u00a0the paid option\u00a0\u00a0(fee) and\u00a0you\u00a0will be\u00a0entitled to 500Mo for a price of 65 \u20ac \/\u00a0month\u00a0, and you have the possibility of adding\u00a020 \u20ac \/\u00a0month\u00a0per\u00a0gigabyte\u00a0additional\u00a0.<\/p>\n

But\u00a0if\u00a0you\u00a0add the\u00a0cost\u00a0of\u00a0hosting\u00a0a\u00a0server\u00a0complete\u00a0, at OVH for\u00a0example\u00a0, which\u00a0runs\u00a0for\u00a0a\u00a0Pro option with 250 GB for\u00a0less\u00a0than 10 \u20ac per\u00a0month\u00a0,\u00a0let’s be\u00a0honest\u00a0,\u00a0this\u00a0solution\u00a0is\u00a0valid,\u00a0only, for\u00a0projects\u00a0relatively\u00a0small\u00a0or\u00a0for\u00a0those\u00a0who\u00a0prefer to\u00a0pay\u00a0a lot for an easy solution instead of investing\u00a0\u00a0in the management of a\u00a0server\u00a0, because\u00a0all\u00a0the solutions that\u00a0follow\u00a0involve\u00a0setting\u00a0up a\u00a0server.<\/p>\n

For more\u00a0information\u00a0on\u00a0this\u00a0solution, I\u00a0invite\u00a0you\u00a0to read\u00a0the article\u00a0\u00a0\u00a0Submit<\/a>\u00a0your<\/a>\u00a0 QGis maps\u00a0on the web with\u00a0QGis\u00a0Cloud<\/a>\u00a0.<\/p>\n

QGis<\/strong>\u00a0server<\/strong><\/p>\n

\"\"<\/p>\n

 <\/p>\n

This is\u00a0the\u00a0server\u00a0version\u00a0of the QGis\u00a0project.\u00a0You\u00a0will\u00a0need\u00a0a\u00a0physical\u00a0server\u00a0and set \u00a0on\u00a0this Apache 2.4 server\u00a0(\u00a0minimum\u00a0versions\u00a0), PHP 5.5, and\u00a0PostgresSQL\u00a09.3,\u00a0before\u00a0installing the\u00a0QGis\u00a0Server.<\/p>\n

The principle is simple (even if installation can, suddenly, become a nightmare): you create your project using QGis Desktop, you transfer your data and project on your server, and then, you set up manually the online setting of your project by modifying the PostgreSQL database tables of QGis Server administration.<\/p>\n

The user\u00a0can\u00a0access\u00a0your\u00a0map\u00a0as well as the\u00a0WFS and\u00a0WMS\u00a0streams.\u00a0With\u00a0this\u00a0solution\u00a0you\u00a0surmount\u00a0the\u00a0data volume problem.<\/p>\n

The interface\u00a0in the\u00a0browser\u00a0is\u00a0a\u00a0simplified\u00a0GIS interface\u00a0(zoom,\u00a0measurement\u00a0,\u00a0display\u00a0of\u00a0attributes\u00a0).<\/p>\n

For more\u00a0information\u00a0about\u00a0QGis\u00a0Server,\u00a0see\u00a0you\u00a0to\u00a0the article\u00a0\u00a0\u00a0Install\u00a0QGis\u00a0Server on Windows 10<\/a><\/p>\n

Putting on<\/strong>\u00a0line<\/strong>\u00a0\u00a0your maps<\/strong><\/p>\n

QGis2Web<\/strong><\/p>\n

\"\"<\/p>\n

 <\/p>\n

With\u00a0this\u00a0solution\u00a0you\u00a0have\u00a0the\u00a0opportunity\u00a0to\u00a0put\u00a0on\u00a0line\u00a0your\u00a0maps\u00a0but\u00a0not the WFS and WMS streams.<\/p>\n

QGis2WXeb\u00a0is\u00a0a\u00a0QGis\u00a0Desktop\u00a0plugin.\u00a0This plugin\u00a0\u00a0allows\u00a0you to export\u00a0your\u00a0QGis local project \u00a0on a\u00a0classic\u00a0HTML\u00a0server\u00a0.\u00a0No\u00a0particular\u00a0software\u00a0is\u00a0needed in the\u00a0server\u00a0.<\/p>\n

The\u00a0map\u00a0will use a\u00a0LeafLet\u00a0code\u00a0or\u00a0OpenLayers\u00a0,\u00a0optionally\u00a0,\u00a0contained\u00a0in\u00a0an\u00a0HTML page.\u00a0Your\u00a0data\u00a0will\u00a0included\u00a0 a\u00a0data with a\u00a0file\u00a0GeoJSON\u00a0format.\u00a0Just\u00a0copy on \u00a0your\u00a0server\u00a0the html page and the\u00a0json\u00a0file\u00a0for\u00a0your\u00a0map to\u00a0be\u00a0in\u00a0line\u00a0.<\/p>\n

The\u00a0big\u00a0advantage\u00a0is that nothing has to be added to the server.\u00a0\u00a0Another advantage \u00a0is\u00a0that\u00a0this\u00a0solution\u00a0is\u00a0an easy first step to\u00a0address\u00a0the\u00a0last\u00a0of the options we\u00a0will see\u00a0afterwards.\u00a0In\u00a0fact\u00a0, the\u00a0generation of\u00a0the OpenLayers\u00a0\u00a0or\u00a0Leaflet\u00a0code can\u00a0be used as\u00a0a basis\u00a0for\u00a0developing\u00a0pages with\u00a0much richer\u00a0functionality.<\/p>\n

The main\u00a0disadvantage\u00a0is the absence of\u00a0 WFS or WMS\u00a0stream and the fact\u00a0that freezes\u00a0the\u00a0data\u00a0while\u00a0copying it\u00a0whenever\u00a0they\u00a0are\u00a0being used\u00a0in a\u00a0project\u00a0.<\/p>\n

For more\u00a0information\u00a0on QGis2Web,\u00a0see\u00a0you\u00a0to\u00a0the article\u00a0\u00a0\u00a0How to export\u00a0your<\/a> QGis <\/u>\u00a0project<\/a>\u00a0\u00a0in\u00a0html page\u00a0in\u00a0two\u00a0clicks\u00a0: Qgis2Leaf.<\/a><\/p>\n

And<\/strong>\u00a0if<\/strong>\u00a0you<\/strong>\u00a0must<\/strong>\u00a0go<\/strong>\u00a0further<\/strong><\/p>\n

If\u00a0your\u00a0needs\u00a0exceed\u00a0what\u00a0has\u00a0been discussed\u00a0so far\u00a0,\u00a0you\u00a0must\u00a0consider\u00a0leaving\u00a0aside\u00a0QGis\u00a0as the\u00a0basis of\u00a0your\u00a0mapping\u00a0on the WEB.\u00a0Several\u00a0architectures\u00a0are available.\u00a0For a start,\u00a0you\u00a0can\u00a0start\u00a0with Postgres \/\u00a0Geoserver\u00a0\/\u00a0OpenLayers\u00a0.\u00a0In\u00a0any\u00a0case\u00a0architecture\u00a0will include\u00a0necessarily\u00a0:<\/p>\n