Laurent, I can think about different ways you can test to tackle your
issues, provided you have two spatial layers that overlap (and without any
intermediate layer creation):
- recent QGIS introduce default values concept (
- i'm not really sure about its limitations though
- add a virtual field (
that you could later recalculate into a simple field
- use the Autofields plugin (http://plugins.qgis.org/plugins/AutoFields/)
- use the SpatialJoin plugin (http://plugins.qgis.org/plugins/spatialJoin/)

Except the SpatialJoin plugin option (which is internally based on it),
you'll need to write an expression likely based on refFunctions plugin
(e.g, geomintersects) someone mentioned above.


2016-12-21 19:23 GMT+01:00 Laurent Bourlet <laurentbourle...@gmail.com>:

> Hi,
> i thought it was more easy ...
> In fact , i don't use a GPS because these points don't need precision :
> they are only used to identify the parcels . And i would like to catch
> their identity ( a number for each parcel and the owner ) if possible with
> a dynamic spatialjoin...
> With booth data ( number of parcel and name of owner ) , i could talk with
> the fisc administration :-)
> Randy was right ...i didn't have the same EPSG for the two layers . It's
> now OK ! but without the feature "dynamic" .
> Indeed , i would avoid building many temporaries layers and i thought it
> existed a plugin for this  " dynamic" feature.
> If no , i will ask my users to make spatialjoins some time to time ...
> Waiting , i will try the solution of Bernd...
> Thank you anyway !
> laurent
> Le 21/12/2016 à 17:46, Bernd Vogelgesang a écrit :
>> Hi,
>> for me this sounds more like he is getting new points once in a while and
>> wants to join those attributes to the new points "automatically" from the
>> parcel layer.
>> The biggest problem for users is to rethink the workflow from the end to
>> the beginning and to know the limitations.
>> The outcome should be a point layer with the polygons attributes. If those
>> points (layer A) are from GPS as Randy assumes, they have to be
>> reprojected to the parcels layer (layer B) before being able to join them
>> spatially(layer C). The spatial join in the toolbox produces layer D.
>> Most probably, the resulting layer D is going to to be edited in some way
>> (adding notes about size, the progress, classifications, whatever), so you
>> will have to find a way to preserve those new attribute while being able
>> to
>> add new points without much trouble.
>> The processing toolbox is a good way to do these steps, though it produces
>> a lot of temporary files cluttering the project.
>> A better way for all those repetitive tasks, is to use the graphical
>> modeller, to create a workflow which only has to be triggered once new
>> points come in, and the resulting file can be saved as new a file e.g.
>> with the current date in the name, so you have kind of an archive and do
>> not
>> overwrite previous files (and destroy your work in case something goes
>> wrong).
>> So I can imagine a model with input layer A (new points in WGS84 without
>> attributes) and a parcel layer B (in whatever projection).
>> reproject layer A and C will be created as an intermediate step.
>> Next input layer is the latest result layer D, reprojected and with
>> attributes.
>> Merge layer C and D -> E. Now delete all columns which are from layer B
>> (from the last spatial join. Unfortunately, you can only delete one field
>> at a time in the modeller, so you'll will have to add the command several
>> times in a row to the model) -> Fn
>> Do the spatial join of Fn with B.
>> The last result G will now hold all points with the corresponding parcel
>> info plus additional fields you might have added to the points.
>> G will be the input D in the next run with fresh points.
>> So, do not add new points to the already existing collection of points in
>> WGS84 (it is never save to edit layers without backup), but just import
>> them as a new input set and then run the model with the parcel layer and
>> the last result layer.
>> The modeller is not as intuitive as it should be, but it can save you a
>> lot of time once you managed to set up a model.
>> Maybe I was completely wrong analysing the problem, but maybe someone
>> else has the problem that fits to my solution ;)
>> Cheers
>> Bernd
>> Am 21.12.2016, 14:07 Uhr, schrieb Randal Hale
>> <rjh...@northrivergeographic.com>:
>> 2 things:
>>> 1. In QGIS there is a processing toolbox (I assume you are one something
>>> as new as version 2.14.8). Open it (it's at the top -> Processing ->
>>> Toolbox). You can search for tools. Search for "join" and you should see a
>>> "Join Attributes by location". This is a spatial join.
>>> 2. THE MOST IMPORTANT THING. You mentioned you had collected points with
>>> a GPS. Possibly these points are in EPSG:4326. I'm going to guess that your
>>> parcel layer isn't. If you right click your parcel layer (in the layers
>>> panel) it will allow you to select properties. On the General Tab you will
>>> see the Coordinate Reference System mentioned and many times it is
>>> something like EPSG:xxxx . A Spatial Join must have the layers in the same
>>> coordinate system.
>>> If it is different - Right Click on your GPS points and "Save as". When
>>> the "Save vector layer as...." window comes up. Save it as a shapefile and
>>> MOST IMPORTANTLY change the CRS to match your parcel layer. Click on the
>>> small globe (that appears to be wearing a hat) and in the filter type in
>>> the number you see for your parcels. You can then select that projection
>>> and Save your file. It should save. You can then perform the "join by
>>> location".
>>> It should work. You are very close though so don't worry.
>>> Randy
>>> On 12/21/2016 01:24 AM, Erwan Conseil wrote:
>>>> Hi
>>>> In my layer B , I have the name of the owner and the number of the
>>>> parcel : this number , a polygon , have a WKT location . All this is in a
>>>> SHP . As I grab points in layer A directly in Qgis (2.18) , I have also a
>>>> SHP . And i need a dynamic join because I have no desire to make the
>>>> spatial join each time...
>>>> Regards
>>>> Laurent
>>>> Le 21 déc. 2016 à 01:30, Randal Hale <rjh...@northrivergeographic.com>
>>>>> a écrit :
>>>>> In your layer B - Do the Names of the Owners have a location (like a
>>>>> tax parcel) or are they a spreadsheet (like Microsoft Excel)?
>>>>> Randy
>>>>> On 12/20/2016 06:03 PM, Laurent Bourlet wrote:
>>>>>> Hi at all
>>>>>> I'm a beginner in Qgis and i would make a dynamic spatialjoin.
>>>>>> In fact , i have created a vector layer ( for example  A) and i grab
>>>>>> points in it when I'm outdoor ( these points are buildings unknowned by 
>>>>>> the
>>>>>> government and so these building are not taxed ...) . I have also a layer
>>>>>> (B) with the name of the owners of these lands .
>>>>>> You see what i would ?...
>>>>>> I would have these names transferred as attribut from B to A .
>>>>>> For that , i think about a spatialjoin with a dynamic feature . So i
>>>>>> have downloaded the two plugins "reffunction" and "spatialjoin".
>>>>>> But i have certainly maked something wrong because i don't succeed ...
>>>>>> Is it the good method ?
>>>>>> And If yes , and if exist a doc about these plugins ...i'll take it
>>>>>> :-))
>>>>>> regards
>>>>>> Laurent
>>>>>> ( pour les francophones ...je repère et saisis des points
>>>>>> représentants  des batiments construits et visibles par Google Map mais
>>>>>> inconnus par le cadastre et donc les impôts ...je voudrais donc enrichir 
>>>>>> la
>>>>>> couche de saisie par les références des parcelles et les noms des
>>>>>> propriétaires par une jointure spatiale dynamique ..à chaque point saisi 
>>>>>> ,
>>>>>> "monte" cette référence )
>>>>>> _______________________________________________
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>>>>> -- -----------------
>>>>> Randal Hale
>>>>> North River Geographic Systems, Inc
>>>>> http://www.northrivergeographic.com
>>>>> 423.653.3611 rjh...@northrivergeographic.com
>>>>> twitter:rjhale
>>>>> _______________________________________________
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