dataschema-text.js revision f805ad34c19740fa0c9729ce35fe59d191912f32
/**
* Provides a DataSchema implementation which can be used to work with
* delimited text data.
*
* @module dataschema
* @submodule dataschema-text
*/
/**
Provides a DataSchema implementation which can be used to work with
delimited text data.
See the `apply` method for usage.
@class DataSchema.Text
@extends DataSchema.Base
@static
**/
SchemaText = {
////////////////////////////////////////////////////////////////////////
//
// DataSchema.Text static methods
//
////////////////////////////////////////////////////////////////////////
/**
Applies a schema to a string of delimited data, returning a normalized
object with results in the `results` property. The `meta` property of
the response object is present for consistency, but is assigned an
empty object. If the input data is absent or not a string, an `error`
property will be added.
Use _schema.resultDelimiter_ and _schema.fieldDelimiter_ to instruct
`apply` how to split up the string into an array of data arrays for
processing.
Use _schema.resultFields_ to specify the keys in the generated result
objects in `response.results`. The key:value pairs will be assigned
in the order of the _schema.resultFields_ array, assuming the values
in the data records are defined in the same order.
_schema.resultFields_ field identifiers are objects with the following
properties:
* `key` : <strong>(required)</strong> The property name you want
the data value assigned to in the result object (String)
* `parser`: A function or the name of a function on `Y.Parsers` used
to convert the input value into a normalized type. Parser
functions are passed the value as input and are expected to
return a value.
If no value parsing is needed, you can use just the desired property
name string as the field identifier instead of an object (see example
below).
@example
// Process simple csv
var schema = {
resultDelimiter: "\n",
fieldDelimiter: ",",
resultFields: [ 'fruit', 'color' ]
},
data = "Banana,yellow\nOrange,orange\nEggplant,purple";
var response = Y.DataSchema.Text.apply(schema, data);
// response.results[0] is { fruit: "Banana", color: "yellow" }
// Use parsers
schema.resultFields = [
{
key: 'fruit',
parser: function (val) { return val.toUpperCase(); }
},
'color' // mix and match objects and strings
];
response = Y.DataSchema.Text.apply(schema, data);
// response.results[0] is { fruit: "BANANA", color: "yellow" }
@method apply
@param {Object} schema Schema to apply. Supported configuration
properties are:
@param {String} schema.resultDelimiter Character or character
sequence that marks the end of one record and the start of
another.
@param {String} [schema.fieldDelimiter] Character or character
sequence that marks the end of a field and the start of
another within the same record.
@param {Array} [schema.resultFields] Field identifiers to
assign values in the response records. See above for details.
@param {String} data Text data.
@return {Object} An Object with properties `results` and `meta`
@static
**/
// Parse results data
} else {
Y.log("Text data could not be schema-parsed: " + Y.dump(data) + " " + Y.dump(data), "error", "dataschema-text");
}
return data_out;
},
/**
* Schema-parsed list of results from full data
*
* @method _parseResults
* @param schema {Array} Schema to parse against.
* @param text_in {String} Text to parse.
* @param data_out {Object} In-progress parsed data to update.
* @return {Object} Parsed data object.
* @static
* @protected
*/
results = [],
// Delete final delimiter at end of string if there
}
// Split into results
if (fieldDelim) {
result = {};
item = results_in[i];
// FIXME: unless the key is an array index, this test
// for fields_in[key] is useless.
fields_in[j];
}
}
} else {
}
return data_out;
}
};