Media

Principle

It is possible to provide documents through Lizmap. To do this, you simply:

• Create a directory called media (in lower case and without accents)

  • either at the same level as the QGIS project

  • or for some specific use-cases, one level up related to the QGIS project, to make it available for all folders (Use a single media folder for many Lizmap folders)

• Put documents in it : pictures, reports, PDFs, videos, HTML or text files

• Icons such as SVG for vector layers

• You can use subdirectories per layer or theme: the organization of media directory content is free.

Lizmap is using the directory for other purposes:

• Adding some javascript, media/js, see Adding your own JavaScript.

• Replacing the default theme, media/theme, see Creating simple themes.

• In the Edition in media/upload/layer_name for pictures uploaded from users.

• Providing documents

Then in Lizmap Web Client you can provide access to these documents for 2 things:

• the popups: the content of one or more field for each geometry can specify the path to the media. For example a photo or pdf field. See Popup.

• the link provided for each group or layer in the Lizmap plugin Layers tab.

Details of these uses is specified below.

Advertencia

Check your file permissions on the media folder. If the folder is not readable, an error will occur.

Dot and dot-dot

On Linux, when you see dot ., it means «this directory».

Two dots, .., one after the other, means «the directory immediately above the current one».

The two dots notation is used in QGIS and Lizmap to go one level up in the tree related to the QGIS project, see Use a single media folder for many Lizmap folders.

Use for links

It is possible to use a relative path to a document for layers or groups link. Links can be filled with the Lizmap plugin Layers tab after selecting the layer or group. See Configure your layers for the Web

The path should be written:

• Starting with media/

• Or with ../media/ if you want to use a single media folder, read Use a single media folder for many Lizmap folders

• With slashes / and not backslashes \

Some examples:

• media/my_layer/metadata_layer.pdf

• media/reports/my_report_on_the_layer.odt

• media/a_picture.png

On the Lizmap Web Client map, if a link has been set up this way for one of the layers, then an icon (i) will be placed to the right of the layer. Clicking this icon opens the linked document in a new browser tab.

Advertencia

For editing capabilities, in Layer properties ‣ Attributes Form, for the given field, you should choose Attachment widget and set the path relative to the project.

If the media is a picture, you should set the Integrated Document Viewer to Image.

Use for SVG

In the QGIS, you can use custom SVG, in your layouts, symbology etc.

QGIS will display a absolute path but in the project, a relative path is saved. In the screenshot below, you can notice the absolute path whereas if you open the QGS file in a text editor, it’s a relative path :

<prop v="../media/custom_svg/croissant.svg" k="name"/>

The path is starting with ../media, it’s using the media folder described below.

Use a single media folder for many Lizmap folders

It’s possible to use a single media folder located in the root data folder. As the folder is located in the parent folder of the QGIS project, it’s allowed to use ../media in the QGIS project, for instance in the attribute table of a layer to access a media file.

This will make files inside this media folder available for all folders, for instance for Javascript, images, PDF…

├── media
│   └── js
│   |    └── default
│   |       ├── another_script.js
│   |       └── one_script.js
│   └── photo_1.jpg
├── my_repository
│   ├── project_a.qgs
│   ├── project_a.qgs.cfg
│   ├── project_b.qgs
│   └── project_b.qgs.cfg
└── other_repo
    ├── media
    │   └── js
    │       ├── default
    │       │   └── script_for_all_projects_in_other_repo.js
    │       └── project_x
    │           └── script_for_project_x.js
    ├── project_x.qgs
    ├── project_x.qgs.cfg
    ├── project_y.qgs
    ├── project_y.qgs.cfg
    ├── project_z.qgs
    └── project_z.qgs.cfg

Use in popups

Principle

As described in the introduction above, you can use a media path in the spatial data layer.

For example, if you want that the popups associated with a layer displayed a picture that depends on each object, just create a new field that will contain the media path to the picture in each row of the layer attribute table, then activate popups for this layer.

Example

Here for example the attribute table of a layer landscape configured to display pictures in the popup. The user has created a picture field in which he places the path to the pictures and a pdf field in which he puts the paths to a pdf file describing the object corresponding to each line.

id	name	description	picture	pdf
1	Marsh	blabla	media/photos/photo_1.png	media/docs/paysage-1.pdf
2	Beach	blibli	media/photos/photo_2.png	media/docs/paysage-2.pdf
3	Moor	bloblo	media/photos/photo_3.png	media/docs/paysage-3.pdf

Nota

In this example, we see that the pictures and PDF file names are normalized. Please follow this example because it allows using the QGIS Field Calculator to create or update automatically the media column data for the entire layer.

Result

Here are the display rules in the popup:

• If you are using a auto popup:

  • If the path points to a picture, the image will be displayed in the popup. Clicking on the picture will display the original image in a new tab.

  • If the path points to a text file or HTML file, the file contents will be displayed in the popup.

  • For any other file types, the popup will display a link to the document that users can download by clicking on the link.

• If you are using a lizmap popup, ${name_of_the_field} will have the full URL to the media, starting by http. This needs to be encapsulated to some HTML, such as <img /> or <a href></a>.

• Then if your are using a qgis popup:

  • [% "name_of_the_field" %] will return only the value of the field, like media/test.pdf.

  • So for links, you need to use HTML, such as <a href="[% "name_of_field" %]">Link</a>.

  • And for images, you need <img> (with an optional link to open it fullscreen) such as

<a href="[% "name_of_field" %]" target="_blank">
    <img src="[% "name_of_field" %]" border="0">
</a>

Illustration

Below is an illustration of a Lizmap popup displaying a picture, a text and a link in the popup: