12 KiB
Named Maps
Named maps are essentially the same as anonymous maps except the MapConfig is stored on the server and the map is given a unique name. Two other big differences are: you can create named maps from private data and that users without an API Key can see them even though they are from that private data.
The main two differences compared to anonymous maps are:
-
auth layer
This allows you to control who is able to see the map based on a token auth -
templates
Since the MapConfig is static it can contain some variables so the client can modify the map's appearance using those variables.
Template maps are persistent with no preset expiration. They can only be created or deleted by a CartoDB user with a valid API_KEY (see auth section).
Create
Definition
```html POST /api/v1/map/named ```Params
- api_key is required
Arguments
- name: There can be at most one template with the same name for any user. Valid names start with a letter or a number, and only contain letters, numbers, dashes (-) or underscores (_).
- auth:
- method
"token"or"open"(the default if no"method"is given). - valid_tokens when
"method"is set to"token", the values listed here allow you to instantiate the named map.
- method
- placeholders: Variables not listed here are not substituted. Variables not provided at instantiation time trigger an error. A default is required for optional variables. Type specification is used for quoting, to avoid injections see template format section below.
- layergroup: the layer list definition. This is the MapConfig explained in anonymous maps. See MapConfig documentation for more info.
- view (optional): extra keys to specify the compelling area for the map. It can be used to have a static preview of a named map without having to instantiate it. It is possible to specify it with
center+zoomor with a bounding boxbbox. Center+zoom takes precedence over bounding box.- zoom The zoom level to use
- center
- lng The longitude to use for the center
- lat The latitude to use for the center
- bounds
- west: LowerCorner longitude for the bounding box, in decimal degrees (aka most western)
- south: LowerCorner latitude for the bounding box, in decimal degrees (aka most southern)
- east: UpperCorner longitude for the bounding box, in decimal degrees (aka most eastern)
- north: UpperCorner latitude for the bounding box, in decimal degrees (aka most northern)
Template Format
A templated layergroup allows the use of placeholders in the "cartocss" and "sql" elements of the "option" object in any "layer" of a layergroup configuration
Valid placeholder names start with a letter and can only contain letters, numbers, or underscores. They have to be written between the <%= and %> strings in order to be replaced.
Example
<%= my_color %>
The set of supported placeholders for a template will need to be explicitly defined with a specific type and default value for each.
Placeholder Types
The placeholder type will determine the kind of escaping for the associated value. Supported types are:
- sql_literal internal single-quotes will be sql-escaped
- sql_ident internal double-quotes will be sql-escaped
- number can only contain numerical representation
- css_color can only contain color names or hex-values
Placeholder default values will be used whenever new values are not provided as options at the time of creation on the client. They can also be used to test the template by creating a default version with new options provided.
When using templates, be very careful about your selections as they can give broad access to your data if they are defined losely.
Instantiate
Instantiating a map allows you to get the information needed to fetch tiles. That temporal map is an anonymous map.
Definition
```html POST /api/v1/map/named/:template_name ```Param
- auth_token optional, but required when
"method"is set to"token"
// params.json
{
"color": "#ff0000",
"cartodb_id": 3
}
The fields you pass as params.json depend on the variables allowed by the named map. If there are variables missing it will raise an error (HTTP 400)
- auth_token optional if the named map needs auth
Example
You can initialize a template map by passing all of the required parameters in a POST to /api/v1/map/named/:template_name.
Valid credentials will be needed if required by the template.
You can then use the layergroupid for fetching tiles and grids as you would normally (see anonymous map section). However you'll need to show the auth_token, if required by the template.
Using JSONP
There is also a special endpoint to be able to initialize a map using JSONP (for old browsers).
Definition
```bash GET /api/v1/map/named/:template_name/jsonp ```Params
- auth_token optional, but required when
"method"is set to"token" - config Encoded JSON with the params for creating named maps (the variables defined in the template)
- lmza This attribute contains the same as config but LZMA compressed. It cannot be used at the same time than
config. - callback: JSON callback name
This takes the callback function (required), auth_token if the template needs auth, and config which is the variable for the template (in cases where it has variables).
url += "config=" + encodeURIComponent(
JSON.stringify({ color: 'red' });
The response is in this format:
callback({
layergroupid: "dev@744bd0ed9b047f953fae673d56a47b4d:1390844463021.1401",
last_updated: "2014-01-27T17:41:03.021Z"
})
Update
Definition
```bash PUT /api/v1/map/named/:template_name ```Params
- api_key is required
Response
Same as updating a map.
Other Info
Updating a named map removes all the named map instances so they need to be initialized again.
Example
If any template has the same name, it will be updated.
If a template with the same name does NOT exist, a 400 HTTP response is generated with an error in this format:
{
"errors" : ["error string here"]
}
Delete
Delete the specified template map from the server and it disables any previously initialized versions of the map.
Definition
```bash DELETE /api/v1/map/named/:template_name ```Params
- api_key is required
Example
On success, a 204 (No Content) response will be issued. Otherwise a 4xx response with an error will be returned.
Listing Available Templates
This allows you to get a list of all available templates.
Definition
```bash GET /api/v1/map/named/ ```Params
- api_key is required
Example
Getting a Specific Template
This gets the definition of a template.
Definition
```bash GET /api/v1/map/named/:template_name ```Params
- api_key is required
Example
Use with CartoDB.js
Named maps can be used with CartoDB.js by specifying a named map in a layer source as follows. Named maps are treated almost the same as other layer source types in most other ways.
var layerSource = {
user_name: '{your_user_name}',
type: 'namedmap',
named_map: {
name: '{template_name}',
layers: [{
layer_name: "layer1",
interactivity: "column1, column2, ..."
}]
}
}
cartodb.createLayer('map_dom_id',layerSource)
.addTo(map_object);
CartoDB.js has methods for accessing your named maps.
- layer.setParams() allows you to change the template variables (in the placeholders object) via JavaScript
- layer.setAuthToken() allows you to set the auth tokens to create the layer