Windshaft-cartodb/04-named-maps.md at master

csubira 2d37d4bf9d Fix typo in named maps guide

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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. You can create Named Maps from private data, and users without an API Key can view your Named Map (while keeping your data private).

The Named Map workflow consists of uploading a MapConfig file to CARTO servers, to select data from your CARTO user database by using SQL, and specifying the CartoCSS for your map.

The response back from the API provides the template_id of your Named Map as the name (the identifier of your Named Map), which is the name that you specified in the MapConfig. You can which you can then use to create your Named Map details, or fetch XYZ tiles directly for Named Maps.

Tip: You can also use a Named Map that you created (which is defined by its name), to create a map using CARTO.js. This is achieved by adding the namedmap type layer source object to draw the Named Map.

The main differences, compared to Anonymous Maps, is that Named Maps include:

auth token
This allows you to control who is able to see the map based on an auth token, and create a secure Named Map with password-protection.
template map
The template map is static and may contain placeholders, enabling you to modify your maps appearance by using variables. Templates maps are persistent with no preset expiration. They can only be created, or deleted, by a CARTO user with a valid API KEY (See auth argument).

Uploading a MapConfig creates a Named Map. MapConfigs are uploaded to the server by sending the server a "template".json file, which contain the MapConfig specifications.

Note: There is a limit of 4,096 Named Maps allowed per account. If you need to create more Named Maps, it is recommended to use a single Named Map and change the variables using placeholders, instead of uploading multiple Named Map MapConfigs.

Create

Definition

POST /api/v1/map/named

Params

Params	Description
api_key	is required
MapConfig	a Named Map MapConfig is required to create a Named Map

template.json

The name argument defines how to name this "template_name".json. Note that there are some requirements for how to name a Named Map template. See the name argument description for details.

{
  "version": "0.0.1",
  "name": "template_name",
  "auth": {
    "method": "token",
    "valid_tokens": [
      "auth_token1",
      "auth_token2"
    ]
  },
  "placeholders": {
    "color": {
      "type": "css_color",
      "default": "red"
    },
    "cartodb_id": {
      "type": "number",
      "default": 1
    }
  },
  "layergroup": {
    "version": "1.0.1",
    "layers": [
      {
        "type": "cartodb",
        "options": {
          "cartocss_version": "2.1.1",
          "cartocss": "#layer { polygon-fill: <%= color %>; }",
          "sql": "select * from european_countries_e WHERE cartodb_id = <%= cartodb_id %>"
        }
      }
    ]
  },
  "view": {
    "zoom": 4,
    "center": {
      "lng": 0,
      "lat": 0
    },
    "bounds": {
      "west": -45,
      "south": -45,
      "east": 45,
      "north": 45
    },
    "preview_layers": {
      "0": true,
      "layer1": false
    }
  }
}

Arguments

Params	Description
name	There can only be 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 (_). This is specific to the name of your Named Map that is specified in the `name` property of the template file.

auth
\|_ method	`"token"` or `"open"` (`"open"` is the default if no method is specified. Use `"token"` to password-protect your map)
\|_ valid_tokens	when `"method"` is set to `"token"`, the values listed here allow you to instantiate the Named Map. See this example for how to create a password-protected map.
placeholders	Placeholders are variables that can be placed in your template.json file's SQL or CartoCSS.
layergroup	the layergroup configurations, as specified in the template. See MapConfig File Format for more information.
view (optional)	extra keys to specify the view 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` + `zoom` or with a bounding box `bbox`. Center+zoom takes precedence over bounding box. Also it is possible to choose which layers are visible or not with `preview_layers` indicating its visibility by layer index or id (visible by default).
---	---
\|_ 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)

Placeholder Format

Placeholders are variables that can be placed in your template.json file. Placeholders need to be defined with a type and a default value for MapConfigs. See details about defining a MapConfig type for Layergroup configurations.

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 inside the Named Maps API.

Example

<%= my_color %>

The set of supported placeholders for a template need to be explicitly defined with a specific type, and default value, for each placeholder.

Placeholder Types

The placeholder type will determine the kind of escaping for the associated value. Supported types are:

Types	Description
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 loosely.

Call

This is the call for creating the Named Map. It is sending the template.json file to the service, and the server responds with the template id.

curl -X POST \
   -H 'Content-Type: application/json' \
   -d @template.json \
   'https://{username}.carto.com/api/v1/map/named?api_key={api_key}'

Response

The response back from the API provides the name of your MapConfig as a template, enabling you to edit the Named Map details by inserting your variables into the template where placeholders are defined, and create custom queries using SQL.

{
  "template_id":"name"
}

Instantiate

Instantiating a Named Map allows you to fetch the map tiles. You can use the Maps API to instantiate, or use the CARTO.js createLayer() function. The result is an Anonymous Map.

Definition

POST /api/v1/map/named/{template_name}

Param

Param	Description
auth_token	`"token"` or `"open"` (`"open"` is the default if not specified. Use `"token"` to password-protect your map)

// params.json, this is required if the Named Map allows variables (if placeholders were defined in the template.json by the user)
{
 "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).

Note: It is required that you include a params.json file to instantiate a Named Map that contains variables, even if you have no fields to pass and the JSON is empty. (This is specific to when a Named Map allows variables (if placeholders were defined in the template.json by the user).

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 auth token will be needed, if required by the template.

Call

curl -X POST \
  -H 'Content-Type: application/json' \
  -d @params.json \
  'https://{username}.carto.com/api/v1/map/named/{template_name}?auth_token={auth_token}'

Response

{
  "layergroupid": "docs@fd2861af@c01a54877c62831bb51720263f91fb33:123456788",
  "last_updated": "2013-11-14T11:20:15.000Z"
}

Error

{
  "errors" : ["Some error string here"]
}

You can then use the layergroupid for fetching tiles and grids as you would normally (see Anonymous Maps).

Update

Definition

PUT /api/v1/map/named/{template_name}

Params

Param	Description
api_key	is required

Response

Same as updating a map.

Other Information

Updating a Named Map removes all the Named Map instances, so they need to be initialized again.

Example

Call

curl -X PUT \
  -H 'Content-Type: application/json' \
  -d @template.json \
  'https://{username}.carto.com/api/v1/map/named/{template_name}?api_key={api_key}'

Response

{
  "template_id": "@template_name"
}

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

Deletes the specified template map from the server, and disables any previously initialized versions of the map.

Definition

DELETE /api/v1/map/named/{template_name}

Params

Param	Description
api_key	is required

Example

Call

curl -X DELETE 'https://{username}.carto.com/api/v1/map/named/{template_name}?api_key={api_key}'

Response

{
  "errors" : ["Some error string here"]
}

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

GET /api/v1/map/named/

Params

Param	Description
api_key	is required

Example

Call

curl -X GET 'https://{username}.carto.com/api/v1/map/named?api_key={api_key}'

Response

{
   "template_ids": ["@template_name1","@template_name2"]
}

Error

{
  "errors" : ["Some error string here"]
}

Get Template Definition

This gets the definition of a requested template.

Definition

GET /api/v1/map/named/{template_name}

Params

Param	Description
api_key	is required

Example

Call

curl -X GET 'https://{username}.carto.com/api/v1/map/named/{template_name}?api_key={api_key}'

Response

{
  "template": {...} // see [template.json](#templatejson)
}

Error

{
  "errors" : ["Some error string here"]
}

JSONP for Named Maps

If using a JSONP (for old browsers) request, there is a special endpoint used to initialize and create a Named Map.

Definition

GET /api/v1/map/named/{template_name}/jsonp

Params

Params	Description
auth_token	`"token"` or `"open"` (`"open"` is the default if no method is specified. Use `"token"` to password-protect your map)
params	Encoded JSON with the params (variables) needed for the Named Map
lmza	You can use an LZMA compressed file instead of a params JSON file
callback	JSON callback name

Call

curl 'https://{username}.carto.com/api/v1/map/named/{template_name}/jsonp?auth_token={auth_token}&callback=callback&config=template_params_json'

Response

callback({
  "layergroupid":"c01a54877c62831bb51720263f91fb33:0",
  "last_updated":"1970-01-01T00:00:00.000Z"
  "cdn_url": {
    "http": "http://cdb.com",
    "https": "https://cdb.com"
  }
})

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:

callback({
  layergroupid: "dev@744bd0ed9b047f953fae673d56a47b4d:1390844463021.1401",
  last_updated: "2014-01-27T17:41:03.021Z"
})

CARTO.js for Named Maps

You can use a Named Map that you created (which is defined by its name), to create a map using CARTO.js. This is achieved by adding the namedmap type layer source object to draw the Named Map.

{
  user_name: '{username}', // Required
  type: 'namedmap', // Required
  named_map: {
    name: '{name_of_map}', // Required, the 'name' of the Named Map that you have created
    // Optional
    layers: [{
      layer_name: "sublayer0", // Optional
      interactivity: "column1, column2, ..." // Optional
    },
    {
      layer_name: "sublayer1",
      interactivity: "column1, column2, ..."
    },
      ...
    ],
    // Optional
    params: {
      color: "hex_value",
      num: 2
    }
  }
}

Note: Instantiating a Named Map over a createLayer does not require an API Key and by default, does not include auth tokens. If you defined auth tokens for the Named Map configuration, then you will have to include them.

CARTO.js has methods for accessing your Named Maps.

layer.setParams() allows you to change the template variables (in the placeholders object) via JavaScript

Note: The CARTO.js layer.setParams() function is not supported when using Named Maps for Torque. Alternatively, you can create a Torque layer in a Named Map
layer.setAuthToken() allows you to set the auth tokens to create the layer

Torque Layer in a Named Map

If you are creating a Torque layer in a Named Map without using the Torque.js library, you can apply the Torque layer by applying the following code with CARTO.js:

 // add cartodb layer with one sublayer
  cartodb.createLayer(map, {
    user_name: '{username}',
    type: 'torque',
    order: 1,
    options: {
            query: "",
            table_name: "named_map_tutorial_table",
            user_name: "{username}",
            tile_style: 'Map { -torque-frame-count:512; -torque-animation-duration:10; -torque-time-attribute:"cartodb_id"; -torque-aggregation-function:"count(cartodb_id)"; -torque-resolution:2; -torque-data-aggregation:linear; } #named_map_tutorial_table_copy{ comp-op: lighter; marker-fill-opacity: 0.9; marker-line-color: #FFF; marker-line-width: 1.5; marker-line-opacity: 1; marker-type: ellipse; marker-width: 6; marker-fill: #FF9900; } #named_map_tutorial_table_copy[frame-offset=1] { marker-width:8; marker-fill-opacity:0.45; } #named_map_tutorial_table_copy[frame-offset=2] { marker-width:10; marker-fill-opacity:0.225; }'      

            },
    named_map: {
      name: "{namedmap_example}",
      layers: [{
        layer_name: "t"
       }]
     }
    })
    .addTo(map)
    .done(function(layer) {

    });
}

Examples of Named Maps created with CARTO.js

Fetching XYZ Tiles for Named Maps

Optionally, authenticated users can fetch projected tiles (XYZ tiles or Mapnik Retina tiles) for your Named Map.

Fetch XYZ Tiles Directly with a URL

Authenticated users, with an auth token, can use XYZ-based URLs to fetch tiles directly, and instantiate the Named Map as part of the request to your application. You do not have to do any other steps to initialize your map.

To call a template_id in a URL:

/{template_id}/{layer}/{z}/{x}/{y}.{format}

For example, a complete URL might appear as:

"https://{username}.carto.com/api/v1/map/named/{template_id}/{layer}/{z}/{x}/{y}.png"

The placeholders indicate the following:

template_id is the response of your Named Map.
layers can be a number (referring to the ## layer of your map), all layers of your map, or a list of layers.
- To show just the basemap layer, enter the number value 0 in the layer placeholder "https://{username}.carto.com/api/v1/map/named/{template_id}/0/{z}/{x}/{y}.png"
- To show the first layer, enter the number value 1 in the layer placeholder "https://{username}.carto.com/api/v1/map/named/{template_id}/1/{z}/{x}/{y}.png"
- To show all layers, enter the value all for the layer placeholder "https://{username}.carto.com/api/v1/map/named/{template_id}/all/{z}/{x}/{y}.png"
- To show a list of layers, enter the comma separated layer value as 0,1,2 in the layer placeholder. For example, to show the basemap and the first layer, "https://{username}.carto.com/api/v1/map/named/{template_id}/0,1/{z}/{x}/{y}.png"

Get Mapnik Retina Tiles

Mapnik Retina tiles are not directly supported for Named Maps, so you cannot use the Named Map template_id. To fetch Mapnik Retina tiles, get the layergroupid to initialize the map.

Instantiate the map by using your layergroupid in the token placeholder:

{token}/{z}/{x}/{y}@{scale_factor}?{x}.{format}

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Named Maps

Create

Definition

Params

template.json

Arguments

Placeholder Format

Example

Placeholder Types

Call

Response

Instantiate

Definition

Param

Example

Call

Response

Error

Update

Definition

Params

Response

Other Information

Example

Call

Response

Delete

Definition

Params

Example

Call

Response

Listing Available Templates

Definition

Params

Example

Call

Response

Error

Get Template Definition

Definition

Params

Example

Call

Response

Error

JSONP for Named Maps

Definition

Params

Call

Response

CARTO.js for Named Maps

Torque Layer in a Named Map

Examples of Named Maps created with CARTO.js

Fetching XYZ Tiles for Named Maps

Fetch XYZ Tiles Directly with a URL

Get Mapnik Retina Tiles

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