parser.js

   1 // ER diagram description parser
   2 class ErDiags
   3 {
   4     constructor(description)
   5     {
   6         this.entities = {};
   7         this.inheritances = [];
   8         this.associations = [];
   9         this.txt2json(description);
  10         // Cache SVG graphs returned by server (in addition to server cache = good perfs)
  11         this.mcdGraph = "";
  12         this.mldGraph = "";
  13         this.sqlText = "";
  14     }
  15
  16     static get TYPES()
  17     {
  18         // SQLite types without null (TODO: be more general)
  19         return ["integer","real","text","blob"];
  20     }
  21
  22     static get CARDINAL()
  23     {
  24         return {
  25             "*": "0,n",
  26             "+": "1,n",
  27             "?": "0,1",
  28             "1": "1,1"
  29         };
  30     }
  31
  32     //////////////////
  33     // PARSING STAGE 1
  34     //////////////////
  35
  36     // Parse a textual description into a json object
  37     txt2json(text)
  38     {
  39         let lines = text.split("\n");
  40         lines.push(""); //easier parsing: always empty line at the end
  41         let start = -1;
  42         for (let i=0; i < lines.length; i++)
  43         {
  44             lines[i] = lines[i].trim();
  45             // Empty line ?
  46             if (lines[i].length == 0)
  47             {
  48                 if (start >= 0) //there is some group of lines to parse
  49                 {
  50                     this.parseThing(lines, start, i);
  51                     start = -1;
  52                 }
  53             }
  54             else //not empty line: just register starting point
  55             {
  56                 if (start < 0)
  57                     start = i;
  58             }
  59         }
  60     }
  61
  62     // Parse a group of lines into entity, association, ...
  63     parseThing(lines, start, end) //start included, end excluded
  64     {
  65         switch (lines[start].charAt(0))
  66         {
  67             case '[':
  68                 // Entity = { name: { attributes, [weak] } }
  69                 let name = lines[start].match(/\w+/)[0];
  70                 let entity = { attributes: this.parseAttributes(lines, start+1, end) };
  71                 if (lines[start].charAt(1) == '[')
  72                     entity.weak = true;
  73                 this.entities[name] = entity;
  74                 break;
  75             case 'i': //inheritance (arrows)
  76                 this.inheritances = this.inheritances.concat(this.parseInheritance(lines, start+1, end));
  77                 break;
  78             case '{': //association
  79                 // Association = { [name], [attributes], [weak], entities: ArrayOf entity indices }
  80                 let relationship = { };
  81                 let nameRes = lines[start].match(/\w+/);
  82                 if (nameRes !== null)
  83                     relationship.name = nameRes[0];
  84                 if (lines[start].charAt(1) == '{')
  85                     relationship.weak = true;
  86                 this.associations.push(Object.assign({}, relationship, this.parseAssociation(lines, start+1, end)));
  87                 break;
  88         }
  89     }
  90
  91     // attributes: ArrayOf {name, [isKey], [type], [qualifiers]}
  92     parseAttributes(lines, start, end)
  93     {
  94         let attributes = [];
  95         for (let i=start; i<end; i++)
  96         {
  97             let field = { name: lines[i].match(/\w+/)[0] };
  98             if (lines[i].charAt(0) == '#')
  99                 field.isKey = true;
 100             let parenthesis = lines[i].match(/\((.+)\)/);
 101             if (parenthesis !== null)
 102             {
 103                 let sqlClues = parenthesis[1];
 104                 let qualifiers = sqlClues;
 105                 let firstWord = sqlClues.match(/\w+/)[0];
 106                 if (ErDiags.TYPES.includes(firstWord))
 107                 {
 108                     field.type = firstWord;
 109                     qualifiers = sqlClues.substring(firstWord.length).trim();
 110                 }
 111                 field.qualifiers = qualifiers;
 112             }
 113             attributes.push(field);
 114         }
 115         return attributes;
 116     }
 117
 118     // GroupOf Inheritance: { parent, children: ArrayOf entity indices }
 119     parseInheritance(lines, start, end)
 120     {
 121         let inheritance = [];
 122         for (let i=start; i<end; i++)
 123         {
 124             let lineParts = lines[i].split(" ");
 125             let children = [];
 126             for (let j=1; j<lineParts.length; j++)
 127                 children.push(lineParts[j]);
 128             inheritance.push({ parent:lineParts[0], children: children });
 129         }
 130         return inheritance;
 131     }
 132
 133     // Association (parsed here): { entities: ArrayOf entity names + cardinality, [attributes: ArrayOf {name, [isKey], [type], [qualifiers]}] }
 134     parseAssociation(lines, start, end)
 135     {
 136         let assoce = { };
 137         let entities = [];
 138         let i = start;
 139         while (i < end)
 140         {
 141             if (lines[i].charAt(0) == '-')
 142             {
 143                 assoce.attributes = this.parseAttributes(lines, i+1, end);
 144                 break;
 145             }
 146             else
 147             {
 148                 // Read entity name + cardinality
 149                 let lineParts = lines[i].split(" ");
 150                 entities.push({ name:lineParts[0], card:lineParts[1] });
 151             }
 152             i++;
 153         }
 154         assoce.entities = entities;
 155         return assoce;
 156     }
 157
 158     //////////////////
 159     // PARSING STAGE 2
 160     //////////////////
 161
 162     static AjaxGet(dotInput, callback)
 163     {
 164         let xhr = new XMLHttpRequest();
 165         xhr.onreadystatechange = function() {
 166             if (this.readyState == 4 && this.status == 200)
 167                 callback(this.responseText);
 168         };
 169         xhr.open("GET", "scripts/getGraphSvg.php?dot=" + encodeURIComponent(dotInput), true);
 170         xhr.send();
 171     }
 172
 173     // "Modèle conceptuel des données". TODO: option for graph size
 174     drawMcd(id, mcdStyle) //mcdStyle: bubble, or compact
 175     {
 176         let element = document.getElementById(id);
 177         mcdStyle = mcdStyle || "compact";
 178         if (this.mcdGraph.length > 0)
 179         {
 180             element.innerHTML = this.mcdGraph;
 181             return;
 182         }
 183         // Build dot graph input
 184         let mcdDot = 'graph {\n';
 185         // Nodes:
 186         Object.keys(this.entities).forEach( name => {
 187             if (mcdStyle == "bubble")
 188             {
 189                 mcdDot += name + '[shape=rectangle, label="' + name + '"';
 190                 if (this.entities[name].weak)
 191                     mcdDot += ', peripheries=2';
 192                 mcdDot += '];\n';
 193                 if (!!this.entities[name].attributes)
 194                 {
 195                     this.entities[name].attributes.forEach( a => {
 196                         let label = (a.isKey ? '#' : '') + a.name;
 197                         mcdDot += name + '_' + a.name + '[shape=ellipse, label="' + label + '"];\n';
 198                         mcdDot += name + '_' + a.name + ' -- ' + name + ';\n';
 199                     });
 200                 }
 201             }
 202             else
 203             {
 204                 mcdDot += name + '[shape=plaintext, label=<';
 205                 if (this.entities[name].weak)
 206                 {
 207                     mcdDot += '<table port="name" BORDER="1" ALIGN="LEFT" CELLPADDING="0" CELLSPACING="3" CELLBORDER="0">' +
 208                         '<tr><td><table BORDER="1" ALIGN="LEFT" CELLPADDING="5" CELLSPACING="0">\n';
 209                 }
 210                 else
 211                     mcdDot += '<table port="name" BORDER="1" ALIGN="LEFT" CELLPADDING="5" CELLSPACING="0">\n';
 212                 mcdDot += '<tr><td BGCOLOR="#ae7d4e" BORDER="0"><font COLOR="#FFFFFF">' + name + '</font></td></tr>\n';
 213                 if (!!this.entities[name].attributes)
 214                 {
 215                     this.entities[name].attributes.forEach( a => {
 216                         let label = (a.isKey ? '<u>' : '') + a.name + (a.isKey ? '</u>' : '');
 217                         mcdDot += '<tr><td BGCOLOR="#FFFFFF" BORDER="0" ALIGN="LEFT"><font COLOR="#000000" >' + label + '</font></td></tr>\n';
 218                     });
 219                 }
 220                 mcdDot += '</table>';
 221                 if (this.entities[name].weak)
 222                     mcdDot += '</td></tr></table>';
 223                 mcdDot += '>];\n';
 224             }
 225         });
 226         // Inheritances:
 227         this.inheritances.forEach( i => {
 228             i.children.forEach( c => {
 229                 mcdDot += c + ':name -- ' + i.parent + ':name [len="1.00", dir="forward", arrowhead="vee", style="dashed"];\n';
 230             });
 231         });
 232         // Relationships:
 233         let assoceCounter = 0;
 234         this.associations.forEach( a => {
 235             let name = !!a.name && a.name.length > 0
 236                 ? a.name
 237                 : '_assoce' + assoceCounter++;
 238             mcdDot += name + '[shape="diamond", style="filled", color="lightgrey", label="' + (!!a.name ? a.name : '') + '"';
 239             if (a.weak)
 240                 mcdDot += ', peripheries=2';
 241             mcdDot += '];\n';
 242             a.entities.forEach( e => {
 243                 mcdDot += e.name + ':name -- ' + name + '[len="1.00", label="' + ErDiags.CARDINAL[e.card] + '"];\n';
 244             });
 245             if (!!a.attributes)
 246             {
 247                 a.attributes.forEach( attr => {
 248                     let label = (attr.isKey ? '#' : '') + attr.name;
 249                     mcdDot += name + '_' + attr.name + '[len="1.00", shape=ellipse, label="' + label + '"];\n';
 250                     mcdDot += name + '_' + attr.name + ' -- ' + name + ';\n';
 251                 });
 252             }
 253         });
 254         mcdDot += '}';
 255         //console.log(mcdDot);
 256         ErDiags.AjaxGet(mcdDot, graphSvg => {
 257             this.mcdGraph = graphSvg;
 258             element.innerHTML = graphSvg;
 259         })
 260     }
 261
 262     // "Modèle logique des données"
 263     drawMld(id)
 264     {
 265         let element = document.getElementById(id);
 266         if (this.mldGraph.length > 0)
 267         {
 268             element.innerHTML = this.mcdGraph;
 269             return;
 270         }
 271         //UNIMPLEMENTED
 272         // TODO: analyze cardinalities (eat attributes, create new tables...)
 273         // mldDot = ...
 274         // this.graphMld = ...
 275     }
 276
 277     fillSql(id)
 278     {
 279         let element = document.getElementById(id);
 280         if (this.sqlText.length > 0)
 281         {
 282             element.innerHTML = this.sqlText;
 283             return;
 284         }
 285         //UNIMPLEMENTED (should be straightforward from MLD)
 286     }
 287 }