Arbitrary size content item generation

A method for generating layout data for a content item template comprising:

• receiving, at one or more data processors, a landing page URL, a first dimensional value, and a second dimensional value;
• receiving, at one or more data processors, a content item template having a set of elements for creating a content item;
• generating, using one or more data processors, a placeholder for each element of the set of elements of the content item template based, at least in part, on the first dimensional value and the second dimensional value;
• determining, using one or more data processors, a space allocation for each element of the set of elements based, at least in part, on the generated placeholders for each element of the set of elements;
• determining, using one or more processors, if a conflict exists based on the determined space allocations for each element of the set of elements;
• and
• storing, in a database, layout data associated with the first dimensional value and the second dimensional value for the content item template based on the determined space allocations and responsive to determining no conflict exists.

A computer readable storage device storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• receiving a request for a content item from a client device comprising a first dimensional value for a content item slot, a second dimensional value for the content item slot, and contextual data;
• determining a landing page URL for a content item to be served responsive to the request from the client device;
• determining content item data for the content item based on the landing page URL and the received contextual data;
• and
• outputting a content item template, the determined content item data, and a script to generate the content item from the content item template and the determined content item data by the client device.