org.autoplot.datasource.URISplit

Class for containing the elemental parts of a URI, and utility routines for working with URIs. We need a working definition of well-formed and colloquial URIs:

 = well-formed URIs =
   :?
   :[?]
   :
   * they are valid URIs: they contain no spaces, etc.
 == params ==
   ampersand-delimited (&) list of name=value pairs, or just value.
   vap+cdaweb:ds=ac_k0_epm&H_lo&timerange=2010-01
 = colloquial URIs =
   * these are Strings that can be converted into URIs.
   * spaces in file names are converted into %20. 
   * spaces in parameter lists are converted into pluses.
   * pluses in parameter lists are converted into %2B.
   * note that if there are pluses but the URI is valid, then pluses may be left alone. 
 

URISplit( )

PARAM_TIME_RANGE

time range subset.

PARAM_TIME_RESOLUTION

PARAM_RANK2

subset of rank 2 data. For example, columns of excel workbook or ascii table. rank2=[3,5] or rank2=Bx-Bz

PARAM_REC_COUNT

used for the number of records to read.

PARAM_ARG_0

first positional parameter, typically interpreted the same as PARAM_ID

PARAM_ID

typically the dataset id.

PARAM_FILE_POLL_UPDATES

some datasources support periodic checks to see if data sources have updated, such as: AggregatingDataSource AbstractDataSources (most of those based on files)

vapScheme

scheme for Autoplot, if provided. e.g. vap+cdf.

scheme

scheme for resource, e.g. "file" or "https"

surl

the complete, modified surl. file:///home/jbf/mydata.qds this is the resource name, and doesn't contain the vapScheme.

resourceUri

the resource that is handled by the DataSource. This may be null if surl doesn't form a valid uri.

authority

the resource uri up to the authority, e.g. http://autoplot.org

path

the resource uri including the path part.

file

contains the resource string up to the query part.

ext

the file/resource extention, like ".cdf" or ".dat".

params

contains the parameters part, a ampersand-delimited set of parameters. For example, column=field2&rank2.

filters

additional processes to be applied to the URI. For example, slice0(0) means slice the dataset at this point.

resourceUriCarotPos

position of the caret after modifications to the surl are made. This is with respect to surl, the URI for the datasource, without the "vap" scheme.

formatCarotPos

position of the caret after modifications to the surl are made. This is with respect to formatted URI, which probably includes the explicit "vap:" scheme.

format

format the URI using vapScheme, file and params. If file is missing but params is present, then return params: vap+cdaweb:ds=myds If file is present, then format with file and params: vap+cdf:file://tmp/my.cdf?myVar Else, just use the surl that is in there already. Note if split.params is non-null, it will be appended with a question mark, even if empty.

Parameters

Returns:

format

convenience method for creating URIs.

Parameters

Returns:

See Also:

formatParams

spaces and other URI syntax elements are URL-encoded. Note some calls of this routine should check for an empty string result and then set split.params=null instead of "", to avoid the extraneous question mark.

Parameters

Returns:

getParam

convenient method for getting a parameter in the URI.

Parameters

Returns:

guardedSplit

only split on the delimiter when we are not within the exclude delimiters. For example, x=getDataSet("http://autoplot.org/data/autoplot.cdf?Magnitude&noDep=T")&y=getDataSet('http://autoplot.org/data/autoplot.cdf?BGSEc&slice1=2')&sqrt(x)

Parameters

Returns:

implicitVapScheme

return the vap scheme in split.vapScheme or the one inferred by the extension. Returns an empty string (not "vap") if one cannot be inferred. e.g: /home/jbf/myfile.jyds --> vap+jyds vap+txt:/home/jbf/myfile.csv --> vap+txt This was introduced as part of the effort to get rid of extraneous "vap:"s that would be added to URIs.

Parameters

Returns:

isUriEncoded

We need a standard way to detect if a string has already been URL encoded. The problem is we want valid URIs that are also readable, so just using simple encode/decode logic is not practical. This means:

• no spaces
• contains %[0-9][0-9]

Parameters

Returns:

makeAbsolute

ensure that the reference, which may be relative, is absolute. NOTE this is only implemented for unix filenames. TODO: Windows. For example:

• /tmp/,foo.dat → /home/t/foo.dat
• /tmp/,/home/jbf/foo.dat → /home/jbf/foo.dat

Parameters

Returns:

makeCanonical

make the URI canonical, with the vap+<ext>: prefix. This will also now sort the parameters, when this can be done.

Parameters

Returns:

makeColloquial

make the URI colloquial, e.g. removing "vap+cdf:" from "vap+cdf:file:///tmp/x.cdf" URIs that do not have a resource URI are left alone.

Parameters

Returns:

maybeAddFile

add "file:/" to a resource string that appears to reference the local filesystem. return the parsed string, or null if the string doesn't appear to be from a file.

Parameters

Returns:

parse

added to avoid widespread use of parse(uri.toString). This way its all being done with same code, and keep the URI abstraction.

Parameters

Returns:

parse

split the url string into components. This does not try to identify the vap scheme, since that might require interaction with the server to get mime type. This inserts the scheme "file://" when the scheme is absent. The string http://www.example.com/data/myfile.nc?myVariable is split into:

• scheme, http
• authority, http://www.example.com
• path, the directory with http://www.example.com/data/
• file, the file, http://www.example.com/data/myfile.nc
• ext, the extenion, .nc
• params, myVariable or null

Parameters

Returns:

parse

split the UI string into components, keeping track of the caret position when characters are inserted. This does not try to identify the vap scheme, since that might require interaction with the server to get mime type. This inserts the scheme "file://" when the scheme is absent. For example, the string http://www.example.com/data/myfile.nc?myVariable is split into:

• vapScheme, vap+nc
• scheme, http
• authority, http://www.example.com
• path, the directory with http://www.example.com/data/
• file, the file, http://www.example.com/data/myfile.nc
• ext, the extension, .nc or null.
• params, myVariable or null.
• filters, the fragment of the URI following hash character.

Parameters

Returns:

parseParams

Split the parameters (if any) into name,value pairs. URLEncoded parameters are decoded, but the string may be decoded already. Items without equals (=) are inserted as "arg_N"=name. This will check that each parameter is unique.

Parameters

Returns:

parseParams

Split the parameters (if any) into name,value pairs. URLEncoded parameters are decoded, but the string may be decoded already. Items without equals (=) are inserted as "arg_N"=name.

Parameters

Returns:

parseTimeRange

Helper method to get the timerange from the URI

Parameters

Returns:

putParam

convenient method for adding or replacing a parameter to the URI.

Parameters

Returns:

removeParam

convenient method to remove a parameter (or parameters) from the list of parameters

Parameters

Returns:

setOtherSchemes

allow parsing of script:, bookmarks:, pngwalk:, etc

Parameters

Returns:

toString

Returns:

uriDecode

convert "+" to " ", etc, by using URLDecoder and catching the UnsupportedEncodingException that will never occur. We have to be careful for elements like %Y than are not to be decoded. TODO: we need to use standard escape/unescape code, possibly changing %Y to $Y beforehand.

Parameters

Returns:

uriEncode

convert " " to "%20", etc, by looking for and encoding illegal characters. We can't just aggressively convert...

Parameters

Returns: