About Themes and Layers
Themes are groups of layers that focus on specific types of information. For example, the feature layers that contain rivers and streams would be included in the Hydrological theme.
Layer is a set of related geographic features such as streets, parcels, or rivers, along with their attributes. Features represents geographic entities as points, lines, and polygons. Each layer references a dataset and specifies how that dataset is displayed using symbols and text labels. When you add a layer to a map, you specify its dataset and set its map symbols and labeling properties. Layers can be used within themes or independently.
The theme (i.e. Grand Parc Mirabel Jonage) itself with its groups of layers.
Individual layers within a theme.
Create and edit Layers
Video tutorial - Create a new layer
The video provides a quick tutorial on how to create a new layer within Knowledge Hub.
How to create a new Layer?
Login with your Knowledge Hub account and open the "Personal" tab where you see two buttons: New Layer and New Theme. Select New Layer.
In the dialog box choose one of the available layer types:
- Vector layer - represents a particular type of feature or particular type of data
- Raster tile layer - a special kind of raster layer that uses standard web tile caches for its display
- WMS layer - a Web Map Service (WMS) layer is based on data from an Open Geospatial Consortium (OGC) WMS server. The WMS layer allows you to access these services over the Internet and add their content to a map.
The Table wizard opens, where you can give your layer a Name and other basic information. Note that the required data vary depending on the type of layer (in our case we have selected Vector layer). When finished click .
In the second step you need to add fields that relate to the records in your new layer.
Field properties (that can be altered) vary depending on the selected data type of field. To change the Type value, choose a new value from the drop-down list:
- Foreign ID - you can add referenced layer as attribute.
- Number - for fields with numeric values.
- Long text - for fields with text values.
- Rich text - associate rich text files with attributes.
- File - you can add image (.jpg), audio (.mp3) or other document (.doc, .xls, .pdf) files as attributes.
- Date and time - choose a date for an attribute value
- Style - set custom style.
- Yes/No - add selection control.
Set custom style and define how your features will be styled on the map
Include optional copyright notice
When you are finished, click to save your changes. The new layer can be found in the "Content" tab.
How to edit Layer properties?
To edit a layer's settings you have to open the layer's details. Under the "Content" (or "Personal", if applicable) tab click on the "Open details" icon.
Layer details are opened under the "Layer" tab.
To edit selected layer click the "Edit layer" icon, which opens Layer editor dialog.
If you want to delete layer click the "Delete" button
after which a notification is displayed where you can confirm or cancel deletion.
The tools for editing layer features can be found at the bottom of the tab. Which tools are available depend on the type of layer and its permissions.
Set of Layer tools:
|Home - reset the view.|
|Add point - add a point on the map.|
|Add line - add a line on the map.|
|Add polygon - add a polygon on the map.|
|Add codelist - add a codelist entry.|
|Activate layer - if the layer is not activated, enable it.|
|Add to favorites - add the selected layer to your favorites list.|
|Add to personal - add the selected layer to your personal list.|
|Export table - opens a layer export wizard to download data.|
|Open table with all layer features - opens all the layer's records as a list view under the map.|
|Import GPX files - upload the GPX file from your computer and import the data.|
To add an existing layer go to the "Content" tab and click the "+" icon on the right side of the green banner.
A dialog box opens, where you can see the list of layers to which you are allowed to access or are publicly accessible. Browse through the layer list or create a filter to limit the number of displayed layers. Select one of the layers (by clicking on it) and press the "Add" button (in top-right corner).
All added layers are visible in the "Content" tab.
Create and edit Themes
Video tutorial - Create a new theme
The video provides a quick tutorial on how to create a new theme within Knowledge Hub.
How to create a new Theme?
Login with your Knowledge Hub account and go to the "Personal" tab where you see two buttons: New Layer and New Theme. Select New Theme.
The theme wizard opens where you enter basic information about the Theme.
Here you can set the following options:
- Not allowed - private theme, not publicly accessible.
- View with link - access to the theme via URL link, for sharing with others but is not searchable.
- Only view - anyone can see the theme.
- Default view - e.g. current position of map and current zoom level.
- Digital elevation model table.
- Logo link URL - link to logo image.
- Copyrights - if your data contains copyright-protected material.
When you are finished press the "Save" button to create your new Theme.
Your new Theme opens in edit mode in the "Content" tab where you can add new groups which will contain layers.
To add new layer to the group click the icon on the group header.
This opens a Layer selection window where you can locate and select layers from the list. Click the "Add" button to confirm your selection.
The layer is added to the new group. Repeat as necessary then click .
How to edit Theme info?
If you want to edit general information (name, description, etc.) open the "Info" tab.
Click the Edit theme icon .
The content of the tab will open in edit mode.
When you finish editing, save changes by clicking the button.
How to edit Theme content?
Go to the "Content" tab where you can add or remove layers contained in the theme.
Click the Edit theme icon to edit or remove layers that are already added.
To add new layer to the group click the icon on the group header.
This opens a Layer selection window where you can locate and select layers from the list. Click the "Add" button to confirm selection.
If you want to remove layer form the group/theme, click the "X" icon next to the layer name.
You can select and review any of the publicly available themes. A list of all themes can be opened in the "Info" tab by clicking the "Open existing theme" button.
A dialog box opens, where you can view all the themes sorted by category (Personal, Favorite). Select one of the themes by clicking on it and click the "Select" button (in top-right corner) to open it.
Layers contained within the Theme are displayed on the map. The list of layers that are included in the theme is visible in the "Content" tab.