ohif-viewer/Packages/viewerbase/lib/parsingUtils.js
2016-11-04 09:08:57 -02:00

78 lines
3.3 KiB
JavaScript

import {dicomParser} from 'meteor/cornerstone';
/**
* A small set of utilities to help parsing DICOM element values.
* In the future the functionality provided by this library might
* be incorporated into dicomParser library.
*/
export const parsingUtils = {
/**
* Check if supplied argument is a valid instance of the dicomParser.DataSet class.
* @param data {Object} An instance of the dicomParser.DataSet class.
* @returns {Boolean} Returns true if data is a valid instance of the dicomParser.DataSet class.
*/
isValidDataSet: function(data) {
return (data instanceof dicomParser.DataSet);
},
/**
* Parses an element tag according to the 'AT' VR definition.
* @param data {Object} An instance of the dicomParser.DataSet class.
* @param tag {String} A DICOM tag with in the format xGGGGEEEE.
* @returns {String} A string representation of a data element tag or null if the field is not present or data is not long enough.
*/
attributeTag: function(data, tag) {
if (this.isValidDataSet(data) && tag in data.elements) {
let element = data.elements[tag];
if (element && element.length === 4) {
let parser = data.byteArrayParser.readUint16,
bytes = data.byteArray,
offset = element.dataOffset;
return 'x' + ('00000000' + (parser(bytes, offset) * 256 * 256 + parser(bytes, offset + 2)).toString(16)).substr(-8);
}
}
return null;
},
/**
* Parses the string representation of a multi-valued element into an array of strings. If the parser
* parameter is passed and is a function, it will be applied to each element of the resulting array.
* @param data {Object} An instance of the dicomParser.DataSet class.
* @param tag {String} A DICOM tag with in the format xGGGGEEEE.
* @param parser {Function} An optional parser function that can be applied to each element of the array.
* @returns {Array} An array of floating point numbers or null if the field is not present or data is not long enough.
*/
multiValue: function(data, tag, parser) {
if (this.isValidDataSet(data) && tag in data.elements) {
let element = data.elements[tag];
if (element && element.length > 0) {
let string = dicomParser.readFixedString(data.byteArray, element.dataOffset, element.length);
if (typeof string === 'string' && string.length > 0) {
if (typeof parser !== 'function') {
parser = null;
}
return string.split('\\').map(function(value) {
value = value.trim();
return parser !== null ? parser(value) : value;
});
}
}
}
return null;
},
/**
* Parses a string to an array of floats for a multi-valued element.
* @param data {Object} An instance of the dicomParser.DataSet class.
* @param tag {String} A DICOM tag with in the format xGGGGEEEE.
* @returns {Array} An array of floating point numbers or null if the field is not present or data is not long enough.
*/
floatArray: function(data, tag) {
return this.multiValue(data, tag, parseFloat);
}
};