Add new coloring attributes via Xena
====================================

https://tumormap.ucsc.edu/?...

HTTP GET

This API takes data for one or more attributes on Xena and adds them as
values to color an existing map.


Example URL
-----------

Line breaks and spaces added for clarity. The string should be URI-encoded.
::

 http://tumormap.ucsc.edu/?
    xena=addAttr&
    p=PancanAtlas/XenaPancanAtlas&
    layout=RPPA&
    hub=https://pancanatlas.xenahubs.net/data/&
    dataset=TCGA_pancancer_10852whitelistsamples_68ImmuneSigs.xena&
    attr=some-categorical-attribute&
    cat=low&
    color=00ff00&
    cat=medium&
    color=000000&
    cat=high&
    color=ff0000

Where:

* **xena** : the type of xena query, one of: [addAttr]
* **p** : a unique map/project identifier
* **layout** : name of a particular layout of nodes within a map
* **dataset** : name of a dataset on the Xena hub
* **attr** : attribute name within the dataset
* **hub** : the URL of the Xena hub
* **cat** : optional; a category name belonging to the attribute
* **color** : optional; a color belonging to the above category in the form 'ff00aa' or 'FF00AA'. Notice there is no '#'.


Response success
----------------

This is returned as HTTP 200.

Response error
--------------

Response errors have some HTTP code other than 200, with JSON content, such as::

 {
    "error": "Some message."
 }