What is an ESRI shapefile?
A shapefile is a geospatial file format containing vector data, such as polygons, lines and points. A shapefile does not contain complete maps, but only features such as roads or houses. In Maptionnaire, a shapefile is therefore categorized as a map overlay. You cannot use a shapefile on its own, but always need a background or basemap to layer it on.
Please note that you should try to keep the size of the shapefiles you use in one survey below 1 MB per file. Using larger files makes it difficult for respondents who use older devices and slower internet connections to access the questionnaire.
Have a shapefile that contains a lot of features? Or would you like to use several shapefiles on the same page, but are worried that they will make the page inaccessible? Turning the shapefiles into a WMS layer will solve these problems!
How to upload an ESRI shapefile to Materials?
Go to Materials, choose the Maps tab, and click the Add Map button on the upper right corner of the page. You can also upload the layer directly in the questionnaire editor in the Maps section of the main settings.
Choose Add ESRI Shapefile from the drop-down menu.
Click Upload and choose the shapefiles from your computer. Please note that the shapefiles must be in a ZIP file format. The ZIP file should include at least .shp, .shx, .dbf and .prj files. You can use any coordinate reference system for the shapefile as long as the projection description file (.prj) is included in the ZIP folder.
Once the file has been uploaded, you are able to edit its settings.
- Name the shapefile.
- Write a Description for it (to be displayed in the item card).
- Write a Control label or the layer name that will be used in the map menu of the questionnaire if several map layers are in use.
- Attribute the shapefile to its producers. The attribution is displayed on the lower right corner of the map.
- Combine layers: If you uploaded several shapefile layers in the same ZIP folder you can choose to combine the layers in which case they will be presented in a single layer, or keep them separate.
Next, you can make decisions related to the features in your shapefile. You can have just one feature, or several, in which case you should fill these settings for each of them.
- Give the feature a name (especially if you have several features)
- Name an ID key, especially if you want to use the shapefile as part of the Clickable map object element. The ID key is any key that distinguishes the elements in your shapefile from each other. For example, if your shapefile contains several points, each point will have a unique key; all of these keys will be listed under the same column in Properties. The name of the column is the ID key.
- If your shapefile contains labels for the different map elements and features, you should also name a Label key, which is the key for the label categorization in the shapefile's attribute table. Remember to also switch on Show feature labels. After naming that, you can make various decisions related to the visual presentation of the labels, such as their placement.
- You can also edit the visual presentation of the shapefile features, such as the color, size and opacity of lines and points.
Finally, click Create item, or Save if you are editing the settings after creating the item.
How to use a shapefile in a questionnaire?
You can add shapefiles in your questionnaire in the general settings of your questionnaire, under the Maps tab. When using a shapefile in a questionnaire, you have to choose it in the Map overlays section. For more detailed instructions, please see this link.