Building a RegEx Testing Page
| Sometimes it's a lot easier to craft a regular expression if you have an interactive environment to play with. The example listings for this chapter include a convenient regular expression "tester" page for creating or troubleshooting your regular expressions. You can also use this tester page to work through some of the RegEx syntax examples in the final section of this chapter, "Crafting Your Own Regular Expressions." To use the page, follow these steps:
TIP If you need to jog your memory on a particular metacharacter, you can click the Help link to bring up the RegEx portion of the ColdFusion documentation. TIP If your regular expression contains subexpressions, choose the Show Subexpressions option to display the actual values matched by each subexpression. Listing 13.12 provides the code for the Regular Expression Tester. You are invited to adapt the page to suit your needs. Listing 13.12. RegExTester.cfm <!--- Filename: RegExTester.cfm Author: Nate Weiss (NMW) Purpose: A page for crafting, testing, and debugging regular expressions ---> <!--- Form parameters ---> <cfparam name="FORM.regEx" type="string" default=""> <cfparam name="FORM.searchText" type="string" default=""> <cfparam name="FORM.searchTextFile" type="string" default=""> <cfparam name="FORM.searchTextURL" type="string" default=""> <cfparam name="FORM.ShowSubExpr" type="boolean" default="no"> <cfparam name="FORM.CaseSensitive" type="boolean" default="No"> <!--- Location of the RexEx pages within the ColdFusion documentation ---> <cfset regExDocURL = "http://livedocs.macromedia.com/coldfusion/6/" & "Developing_ColdFusion_MX_Applications_with_CFML/regexp.htm"> <!--- If the user is uploading a file ---> <cfif FORM.searchTextFile neq ""> <!--- Obtain a temporary file to store the uploaded text in ---> <cfset tempFileName = getTempFile(getTempDirectory(), "rgx")> <!--- Accept the file upload ---> <cffile action="upload" filefield="FORM.searchTextFile" destination="#tempFileName#" nameconflict="Overwrite"> <!--- Read the contents of the file into the FORM.SearchText variable ---> <cffile action="read" file="#tempFileName#" variable="FORM.SearchText"> <!--- Delete the temporary file ---> <cffile action="delete" file="#tempFileName#"> <!--- If the user is providing a URL to get the search text from ---> <cfelseif left(FORM.searchTextURL, 4) eq "http"> <!--- Fetch the text over HTTP ---> <cfhttp method="get" url="#FORM.searchTextURL#"> <!--- If we appear to have connected succesfully to the URL ---> <cfif cfhttp.fileContent neq "Connection Failure"> <!--- Use the fetched text from here on ---> <cfset FORM.searchText = cfhttp.fileContent> </cfif> </cfif> <html> <head><title>Regular Expression Test Page</title></head> <body> <!--- Some styles to make the page look nice ---> <style> body {font-family:arial;font-size:12px} input {font-size:11px} textarea {font-size:11px} th {background:#8888FF;color:white;text-align:left} td {background:#CCCC99;color:black;font-size:12px} td.RowA {background:#CCCC99} td.RowB {background:#EEEEBB} </style> <cfoutput> <!--- Create a self-submitting form ---> <FORM ACTION="#CGI.script_name#" METHOD="post" ENCTYPE="multipart/form-data"> <table border="1" cellPadding="4" cellSpacing="0" width="550"> <tr> <th >Regular Expression Tester</th> </tr> <tr> <td > <!--- Text input for the regular expression itself ---> <b>Enter a regular expression:</b><br> <input name="regEx" type="text" size="65" style="font-size:13px" value="#htmlEditFormat(FORM.regEx)#"> <!--- Submit button to start the search ---> <input type="submit" value="Match Now" style="font-weight:bold"><br> <!--- Checkbox to control case-sensitivity ---> <input type="checkbox" name="casesensitive" <cfif FORM.caseSensitive>checked</cfif> value="yes"> <label for="casesensitive">Case sensitive</label> <!--- Radio buttons to display matches vs. subexpressions ---> <input type="radio" name="showSubExpr" <cfif not FORM.showSubExpr>checked</cfif> value="no"><label for="showSubExprNo">Show matched text</label> <input type="radio" name="showSubExpr" <cfif FORM.showSubExpr>checked</cfif> value="yes"><label for="showSubExprYes">Show subexpressions</label> <a href="#regExDocURL#" target="RegExDocs">Help</a> <!--- Textarea where user can type the text to search ---> <p><b>And the text you wish to search:</b><br> <textarea name="searchText" wrap="off" cols="70" rows="6"> #htmlEditFormat(FORM.searchText)# </textarea><br> <!--- Text input for providing a URL ---> Or, provide a file or URL to get the text from:<br> URL: <input name="searchTextURL" type="text" size="35"> <!--- File input for uploading a text file to search ---> File: <input name="searchTextFile" type="file" size="30"> </td> </tr> </table> </form> </cfoutput> <!--- When the form is submitted... ---> <cfif FORM.regEx neq ""> <!--- Include UDF library of regular expression functions ---> <!--- This allows us to use the REFindMatches() function ---> <cfinclude template="RegExFunctions.cfm"> <!--- If the RegEx is using "multiline mode", adjust the text ---> <!--- so that only linefeed characters are used to separate lines ---> <cfif left(FORM.regEx, 4) eq "(?m)"> <cfset FORM.searchText = adjustNewlinesToLinefeeds(FORM.searchText)> </cfif> <cftry> <!--- Perform the regular expression search ---> <!--- Results are returned as a query object with three columns: ---> <!--- "Pos" - the position of the match ---> <!--- "Len" - the length of the match ---> <!--- "Found" - the actual text of the match ---> <cfset matchQuery = reFindMatches(FORM.regEx, FORM.searchText, FORM.caseSensitive)> <!--- If any errors occur ---> <cfcatch type="Expression"> <!--- If it has to do with regular expression, show friendly message ---> <cfif CFCATCH.message contains "malformed regular expression"> <p><b>Sorry, there is a problem with your regular expression.</b><br> <cfoutput>#CFCATCH.Detail#<br></cfoutput> <cfabort> <cfelse> <cfrethrow> </cfif> </cfcatch> </cftry> <cfoutput> <!--- Display the number of matches found ---> Matches Found: #matchQuery.RecordCount#<br> <!--- If there is at least one match... ---> <cfif matchQuery.recordCount gt 0> <!--- Display the matches in a simple HTML table ---> <div style="height:200px;overflow-y:auto;width:550"> <table border="0" cellPadding="2" cellSpacing="0" width="550"> <tr> <cfif FORM.showSubExpr> <cfloop from="1" to="#matchQuery.SubExprCount#" index="i"> <th>Sub-Expr #i#</th> </cfloop> <cfelse> <th width="*">Match</th> <th width="50">Position</th> <th width="50">Length</th></tr> </cfif> </tr> <cfloop query="matchQuery"> <!--- Alternating row colors ---> <cfset class = iif(currentRow mod 2 eq 0, "'RowA'", "'RowB'")> <tr> <cfif FORM.showSubExpr> <cfloop from="1" to="#matchQuery.SubExprCount#" index="i"> <td width="#round(100/matchQuery.SubExprCount)#%"> #htmlEditFormat(matchQuery["SubExpr#i#"][currentRow])# </td> </cfloop> <cfelse> <td width="450"> #htmlEditFormat(matchQuery.Found)# </td> <td width="50">#matchQuery.pos#</td> <td width="50">#matchQuery.len#</td> </cfif> </tr> </cfloop> </table> </div> </cfif> </cfoutput> </cfif> </body> </html> NOTE Listing 13.12 makes use of the reFindMatches() and adjustNewlinesToLinefeeds() functions discussed in the previous section, "Some Convenient RegEx UDFs." As such, it requires the RegExFunctions.cfm UDF library file to be present. |
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